Revista do IC do RS 2003

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Revista do IC do RS 2003

  1. 1. Revista Médica do Instituto de Cardiologia Ano 3 / Volume 1 - www.cardiologia.org.br
  2. 2. ______________________________________________ INDICE 2003 DYNAMICS OF THE PULMONARY VENOUS FLOW IN THE FETUS AND ITS ASSOCIATION VASCULAR DIAMETER Paulo ZIELINSKY, Antônio L. PICCOLI Jr, Eduardo I. GUS, João Luiz MANICA, Fabíola SATLER, Luiz Henrique NICOLOSO, Stelamaris LUCHESE, Silvana MARCANTONIO, Marlui SCHEID, Do- mingos M. HATEM. Circulation 2003;108:2377-2380 COMPARISON OF LEFT VENTRICULAR ELECTROMECHANICAL MAPPING AND LEFT VENTRICULAR ANGIOGRAPHY: DEFINING PRACTICAL STANDARTS FOR ANALYSIS OF NOGATM MAPS. Rogério SARMENTO-LEITE, Guilherme V. SILVA, Hans F.R. DOHMAN, Ricardo M. ROCHA, Hans J.F. DOHMAN, Nelson Durval S.G. MATTOS, Luis Antonio CARVALHO, Carlos A.M. GOTTSCHALL. Texas Heart Institute Journal 2003;30:19-26 Impact of renal denervation on renal content of GLUT1, albuminuria, and urinary TGF-B1 in streptozotocina-induced diabetic rats. Beatriz D. SCHAAN, Sílvia LACCHINI, Marcello C. BERTOLUCI, Maria C. IRIGOYEN, Ubiratan F. MACHADO, Helena SCHMID. Neuroscience: Basic and Clinical 2003;104:88-94 RIGHT VENTRICLE BRONCHOGENIC CYST. Paulo R. PRATES, , Abud HOMSI-NETO, Marinez BARRA, João Ricardo M. SANT’ANNA, Renato A.K. KALIL, Ivo A. NESRALLA. Texas Heart Institute Journal 2003;30(1):71-73. NEW LEAD FOR IN UTERO PACING FOR FETAL CONGENITAL HEART BLOCK. Renato S. ASSAD, Paulo ZIELINSKY, Renato A.K. KALIL, Gustavo G. LIMA, Anna M. ARAMAYO. Journal Thoracic and Cardiovascular Surgery 2003;126(1):300-302 O PAPEL DA PROTEÍNA QUINASE C NO DESENVOLVIMENTO DAS COMPLICAÇÕES VASCULARES DO DIABETES MELLITUS. Beatriz D. SCHAAN. Arquivos Brasileiros de Endocrinologia e Metabologia 2003;47(6):654-662 PULSATILIDADE VENOSA PULMONAR EM FETOS DE MÃES DIABÉTICAS: UM ESTUDO DOPPLER-ECOCARDIOGRÁFICO PRÉ-NATAL. Paulo ZIELINSKY, Antonio L. PICCOLI Jr, Lucas TEIXEIRA, Eduardo I. GUS, João L. MANICA, Fabíola SATLER, Humberto VAZ, Luiz Henrique NICOLOSO, Stelamaris LUCHESE, Marlui SCHEID, Silvana MARCANTONIO, Domingos M. HATEM. Arquivos Brasileiros de Cardiologia 2003; 81(6): 600-603 FATORES PREDITIVOS DE COMPLICAÇÕES APÓS O IMPLANTE DE “STENTS” CORONARIANOS. Alexandre S. QUADROS, Carlos A.M. GOTTSCHALL, Rogério SARMENTO-LEITE, Miguel GUS, Rodrigo WAINSTEIN, André BUSSMANN. Arquivos Brasileiros de Cardiologia 2003;80(5): 531-537 ASSOCIAÇÃO ENTRE A DOENÇA ATEROSCLERÓTICA CORONARIANA E A ESPESSURA MÉDIO- INTIMAL DA CARÓTIDA COMUM ATRAVÉS DA ULTRA-SONOGRAFIA. Eduardo M. ROSA, Caroline KRAMER, Iran CASTRO. Arquivos Brasileiros de Cardiologia 2003;80(6):585-8 BEHAVIOUR OF THE “SEPTUM PRIMUM” MOBILITY IN THIRD TRIMESTER FETUSES WITH MYOCARDIAL HYPERTROPHY. Cora FIRPO, Paulo ZIELINSKY. Ultrasound in Obstetrics & Gynecology 2003;21:445-50
  3. 3. ________________________________DISSERTAÇÕES A Teoria do Autocuidado no Manejo dos Fatores de Risco (Obesidade, Hipertensão e Tabagismo) em Pacientes Pós-Infarto Agudo do Miocárdio. Autor: Silvia GOLDMEIER - Orientador: Prof. Dr. Iran CASTRO Variações da Função Diastólica do Ventrículo Esquerdo de Acordo com a Idade Através da Ecocardiografia com Doppler Tissular. Márcia D. PEDONE - [Orientador: Prof. Dr. Iran CASTRO] Correlação e concordância entre medidas ecocardiográficas obtidas durante o exame no ecocardiógrafo, com medidas de imagens digitalizadas em estação de trabalho dedicada. Maria Amélia B. HATEM - [Orientador: Prof. Dr. Iran CASTRO] Aferição da Taxa de Eritroblastos e dos Parâmetros do Equilíbrio Acidobásico no Sangue da Veia Umbilical no Nascimento Capacitação da Enfermagem na Aplicação da Metodologia. Maria Antonieta MORAES [Orientador: Prof. Dr. Ivo BEHLE] O Uso do Balão Intra-Aórtico no Pré-Operatório de Cirurgia de Revascularização Miocárdica Associada à Disfunção Ventricular Grave. Marcelo KERN [Orientador: Prof. Dr. João Ricardo Sant’Anna] Triiodotironina Oral na Prevenção da Redução do Hormônio da Tireóide em Cirurgia Cardíaca Valvar em Adultos. Ana Paula Arbo MAGALHÃES [Orientador: Profª. Drª. Beatriz D. SCHAAN] Associação do perfil lipídico, da proteína C reativa ultra sensível, do fibrinogênio e da glicemia com a evolução intra e pós-hospitalar de pacientes com síndrome isquêmica agudas. Elizabeth DUARTE [Orientador: Profª. Drª. Vera L. PORTAL] Prevalência de Hipertensão Arterial Sistêmica em uma População acima de 40 anos em Caxias do Sul. José Antonio V. MASCIA [Orientador: Prof. Dr. Mauro R.S. MOURA] Banca avaliadora: Prof. Dr. Celso Blacher / UFRGS; Prof. Dr. Iran Castro / FUC; Profª. Drª. Vera L. PORTAL / FUC. Alternativa Prática do Uso de Amiodarona Oral na Prevenção de Fibrilação e Flutter Atrial no Pós-Operatório de Cirurgia de Revascularização Miocárdica. Rafael ALCALDE [Orientador: Prof. Dr. Iran CASTRO] Distribuição do Fluxo em Artérias Pulmonares na Anastomose de Blalock-Taussig Modificada Conforme Modelo Computadorizado. Francisco MICHIELIN FILHO [Orientação: Prof. Dr. João Ricardo M. SANT’ANNA] Ablação da condução atrioventricular por cateter de radiofreqüência em pacientes com fibrilação atrial: efeitos na qualidade de vida. Carlos Antônio KALIL [Orientador: Prof. Dr. Renato A.K. Kalil]
  4. 4. _____________________________________________________________EDITORIAL A REVISTA MÉDICA DO INSTITUTO DE CARDIOLOGIA DO RIO GRANDE DO SUL/ FUNDAÇÃO UNIVERSITÁRIA DE CARDIOLOGIA foi criada por Rubem Rodrigues como o Órgão de divulgação cultural e científico desta Instituição, tendo retratado artigos de grande utilidade cultural nas áreas de Cardiopatia Isquêmica (Vol 1 Nº 1e 2) Prevenção em Cardiologia (Vol 1 Nº 3) e Cardiologia Pediátrica e Fetal (Revista Vol 2 Nº 2 - Cardiologia Pediátrica e Fetal II) tendo contribuído para a divulgação da ciência cardiovascular e da melhoria da prática cardiológica em nosso meio. Recentemente, a revista sofreu as conseqüências das dificuldades econômicas de nosso país e teve sua divulgação interrompida por falta de patrocinadores. Inconformados com a impossibilidade de levar adiante o projeto iniciado pelo Prof. Rubem e tão bem conduzido posteriormente pelo Editor Nelson C. Nonohay com auxílio de um excelente Conselho Editorial tendo como Presidente Ivo A. Nesralla, Cardiologia Clínica Oscar Dutra, Cardiologia Setorial Nestor S. Daudt e Epidemiologia Iseu Gus , os professores do curso de pós-graduação reunidos decidiram manter a revista em um formato eletrônico, sem custos e com a intenção de divulgar a produção intelectual da Instituição. Esta mudança de foco deve ficar bem definida para os nossos leitores e associados, particularmente os que não atuam no âmbito acadêmico. As modificações em nosso perfil editorial foram motivadas pela impossibilidade econômica de manter a revista em papel e os artigos menos voltados às questões utilitárias e sim à investigação cardiovascular inovadora, provenientes de teses da nossa pós-graduações e das publicações realizadas por nossa massa crítica acadêmica em revistas nacionais e internacionais. Assim pretendemos dar continuidade a revista atualizando nossos leitores do que tem-se produzido em publicações na casa, de forma concentrada e acessível. Por motivos alheios a nossa vontade não podemos em um primeiro número dispor toda a demanda reprimida de publicações realizadas por membros desta casa, assim pedimos colaborações no sentido de nos balizar as publicações que lhes forem mais prementes de serem divulgadas neste meio de comunicação. Aproveitamos para lembrar a todos que a pesquisa no IC/FUC depende de verbas e que o novo FAPICC esta aceitando qualquer tipo de doação, assim como a possibilidade de comerciais nesta página são bem-vindas, bastando entrar em contato conosco, icfuc@cardiologia.org.br Dr. Iran Castro Prof. do Programa de Pós-Graduação IC/FUC, Editor Dr. Renato A. K. Kalil Diretor Científico do IC/FUC
  5. 5. Dynamics of the Pulmonary Venous Flow in the Fetus and Its Association With Vascular Diameter Paulo Zielinsky, MD, PhD; Antônio Piccoli, Jr, MD; Eduardo Gus, MD; João Luiz Manica, MD; Fabíola Satler, MD; Luiz Henrique Nicoloso, MD, MSc; Stelamaris Luchese, MD, MSc; Silvana Marcantonio, MD, MSc; Marlui Scheid, MD; Domingos Hatém, MD, MSc Background—The usual positioning of the Doppler sample volume to assess fetal pulmonary vein flow is in the distal portion of the vein, where the vessel diameter is maximal. This study was performed to test the association of the pulmonary vein pulsatility index (PVPI) with the vessel diameter. Methods and Results—Twenty-three normal fetuses (mean gestational age, 28.6Ϯ5.3 weeks) were studied by Doppler echocardiography. Pulmonary right upper vein flow was assessed adjacent to the venoatrial junction (“distal” position) and in the middle of the vein (“proximal” position). The vessel diameter was measured by 2D echocardiography with power Doppler, and the PVPI was obtained by the ratio (maximal velocity [systolic or diastolic peak]Ϫminimal velocity [presystolic peak])/mean velocity. The statistical analysis used t test and exponential correlation studies. Mean distal diameter was 0.33Ϯ0.10 cm (0.11 to 0.57 cm), and mean proximal diameter was 0.16Ϯ0.08 cm (0.11 to 0.25 cm) (PϽ0.0001). Mean distal PVPI was 0.84Ϯ0.21 (0.59 to 1.38), and mean proximal PVPI was 2.09Ϯ0.59 (1.23 to 3.11) (PϽ0.0001). Exponential inverse correlation between pulmonary vein diameter and pulsatility index was highly significant (PϽ0.0001), with a determination coefficient of 0.439. Conclusions—In the normal fetus, the pulmonary venous flow pulsatility decreases from the lung to the heart, and this parameter is inversely correlated to the diameter of the pulmonary vein, which increases from its proximal to its distal portion. This study emphasizes the importance of the correct positioning of the Doppler sample volume, adjacent to the venoatrial junction, to assess pulmonary venous flow dynamics. (Circulation. 2003;108:2377-2380.) Key Words: fetus Ⅲ echocardiography Ⅲ blood flow Ⅲ physiology Ⅲ vessels Fetal Doppler echocardiography is an expanding field, and functional studies are now an essential part of the routine examination. The paramount importance of the events taking place in the left atrium, such as flow through the foramen ovale, coming from the ductus venosus, mitral flow patterns, and flow from the pulmonary veins, are directly related to left atrial pressure and volume and to left ventricular relaxation and compliance. Analysis of the pulmonary vein flow has been used along with other parameters in the assessment of fetal diastolic function.1,2 The pulmonary vein pulsatility index (PVPI) reflects the relative impedance to the forward flow and is believed to be better comparable than absolute values of individual waveforms and independent of the insonation angle.3 The standard position of the Doppler sample volume to obtain the pulmonary vein flow is in the distal portion of the vein, adjacent to the venoatrial junction, where the vessel diameter is maximal. Morphometric studies of the pulmonary venous vasculature confirm that the pulmonary veins show a tapering pattern from the left atrium to the hylum,4,5 and mathematical models show that the flow wave is altered by the change in the cross-sectional area of the vessel.6–10 It seemed logical to suppose that if the Doppler sampling were performed more proximally, in a region where the pulmonary vein size was smaller, the results could be different, possibly expressing an increased impedance to the forward flow where the vessel was narrower. Thus, this study was performed to test the hypothesis that the PVPI should be lower in the venoatrial junction than at a more proximal site and that this behavior should be correlated to the progressive decrease in the vessel diameter from the left atrium toward the lung. Methods Twenty-three normal fetuses, with a mean gestational age of 28.6Ϯ5.3 weeks (20 to 36 weeks) were studied by cross-sectional and Doppler echocardiography. Any maternal or fetal abnormalities excluded the patient from the study. Commercially available equip- ment with 2D, M-mode, pulsed, and continuous Doppler; color flow mapping; and power angio-Doppler capabilities was used. Considering the established reproducibility of transthoracic pul- monary venous Doppler flow indices,11 intraobserver and interob- server variability was not calculated. Received April 28, 2003; revision received July 11, 2003; accepted July 11, 2003. From the Fetal Cardiology Unit, Institute of Cardiology of Rio Grande do Sul, Porto Alegre, Brazil. Correspondence to Dr Paulo Zielinsky, Instituto de Cardiologia do Rio Grande do Sul, Unidade de Pesquisa, Av Princesa Isabel, 370, Santana, Porto Alegre Zip 90.620-001. E-mail pesquisa@cardnet.tche.br or zielinsky@cardiol.br © 2003 American Heart Association, Inc. Circulation is available at http://www.circulationaha.org DOI: 10.1161/01.CIR.0000093195.73667.52 2377
  6. 6. Pulmonary venous flow was assessed in the upper right vein at 2 different sites: adjacent to the opening to the left atrium (“distal” position) and in the middle of the vein (“proximal” position), below the level of the middle lobe vein.12 The vessel diameter was measured at the 2 sites by 2D echocardiography enhanced with power Doppler (Figure 1). PVPI was obtained by the pulsed Doppler ratio, as follows: (maximal velocity [systolic or diastolic peak]Ϫminimal velocity [presystolic peak])/mean velocity, electron- ically calculated by the equipment after manual tracing of the pulmonary waveforms during the entire cardiac cycle (Figure 2). The mean of 5 measurements was considered, in the absence of fetal breathing movements. Informed consent was obtained in every case. Statistical analysis used t test and exponential correlation studies, with a confidence limit of 99%. Results Mean distal internal diameter was 0.33Ϯ0.10 cm (0.11 to 0.57 cm), with a median of 0.32 cm, and mean proximal diameter was 0.16Ϯ0.08 cm (0.11 to 0.25 cm), with a median of 0.16 cm (PϽ0.0001) (Figure 3). There was no statistical difference between mean systolic (S wave) and diastolic (D wave) peak velocities at the 2 sites (distal Sϭ0.20Ϯ0.09 m/s [0.17 to 0.58 m/s], proximal Sϭ0.22Ϯ0.08 m/s [0.14 to 0.52 m/s]; distal Dϭ0.21Ϯ0.09 m/s [0.14 to 0.53 m/s], proximal Dϭ0.19Ϯ0.14 m/s [0.10 to 0.53 m/s]). Mean peak presystolic velocity (A wave) was significantly higher in the distal position (Aϭ0.12Ϯ0.04 m/s [0.06 to 0.16 m/s]) than at the proximal site (AϭϪ0.12Ϯ0.07 m/s [Ϫ0.13 to 0.09 m/s]) (Pϭ0.002). Figure 1. Right upper pulmonary (PULM) vein imaging in a 33-week fetus by 2D echocardiography enhanced by power Doppler. Notice progressive increase of vessel diameter toward left atrium (LA). Figure 2. Doppler tracing of a typical distal pulmonary vein flow. Velocities were electronically calculated after manual tracing of waveforms. Presystolic velocity is 0.09 m/s, and calculated pul- satility index is 1.21. Figure 3. Diagram showing median distal and proximal pulmo- nary vein (PV) diameters. Horizontal bars above and below median boxes represent maximal and minimal values of PV diameter. 2378 Circulation November 11, 2003
  7. 7. Mean distal PVPI was 0.84Ϯ0.21 (0.59 to 1.38), with a median of 0.77, and mean proximal PVPI was 2.09Ϯ0.59 (1.23 to 3.11), with a median of 2.22 (PϽ0.0001) (Figure 4). Exponential inverse correlation between pulmonary vein diameter and pulsatility index was highly significant (PϽ0.0001), with a determination coefficient of 0.439 (Fig- ure 5). Discussion Studies on human embryonic and fetal lungs demonstrate that the pulmonary arteries form by vasculogenesis,13 but there is less information on the early development of the pulmonary veins. Studies on maturation of pulmonary venous smooth muscle suggest that a developmentally regulated remodeling of the vein walls may reduce resistance to blood flow in fetal life.14 It has also been shown that the development of the airways and pulmonary veins occurs at different times and that the branching patterns of these structures are not inter- dependent.15–17 The common pulmonary vein develops within the sinus venosus segment18 and is later incorporated into the morphological left atrium.19 Morphometric studies in ani- mals4 and in humans5 demonstrate that the branching patterns of the pulmonary veins show many orders of tapering, from the left atrium, where the diameter of the vessel (and its cross-sectional area) is maximal, toward the pulmonary bed, where it is minimum. An experimental hemodynamic study showed that the pulmonary vein pressure varied depending on the recording site, resembling pulmonary artery pressure closer to the pulmonary capillary bed and left atrial pressure closer to the venoatrial junction.20 The same rationale applies when the flow velocities from the lung to the heart are considered, with the pulmonary vein diameter at the different sites probably being the main determinant, as is demonstrated in the present study. Other factors involved have been evalu- ated, such as left atrium relaxation and compliance and left ventricular function.21–27 Pulmonary vein relaxation, medi- ated by C-type natriuretic peptide, is uniform and thus does not allow segmental variations.28 The effects of vessel tapering in the pulmonary circulation have been studied by nonlinear models,6,10 and the role of the vessel cross-sectional area in the flow wave dynamics has also been assessed.7 A theoretical model designed to evaluate the wave transmission in a stenotic tube suggests that nonse- vere stenoses may cause significant wave reflections,8 which is consistent with the idea that the flow impedance is related to the diameter of the tube. Because Doppler analysis of the pulmonary venous wave- forms is widely used in clinical practice,1–3,29–35 it is imper- ative to have the sample volume correctly positioned in the distal portion of the pulmonary vein, near the venoatrial junction, to achieve reliable results, because this fetal study showed that the presystolic velocity decreases and the pulsa- tility index increases when a more proximal site is sampled. It has been demonstrated that, in the normal fetus, the pulsatility of the pulmonary vein decreases along the way from the lung to the heart and that this parameter is inversely correlated to the cross-sectional diameter of the pulmonary vein, which increases from the proximal to the distal portion of the vessel. References 1. Hong YM, Choi JY. Pulmonary venous flow from fetal to neonatal period. Early Hum Dev. 2000;57:95–103. 2. Crowe DA, Allan LD. Patterns of pulmonary venous flow in the fetus with disease of the left heart. Cardiol Young. 2001;11:369–374. 3. Lenz F, Chaoui R. Reference ranges for Doppler-assessed pulmonary venous blood flow velocities and pulsatility indices in normal human fetuses. Prenat Diagn. 2002;22:786–791. 4. Gan RZ, Tian Y, Yen RT, et al. Morphometry of the dog pulmonary venous tree. J Appl Physiol. 1993;75:432–440. 5. Huang W, Yen RT, McLaurine M, et al. Morphometry of the human pulmonary vasculature. J Appl Physiol. 1996;81:2123–2133. 6. Lucas CL. Fluid mechanics of the pulmonary circulation. Crit Rev Biomed Eng. 1984;10:317–393. 7. Demiray H. Waves in initially stressed fluid-filled thick tubes. J Biomech. 1997;30:273–276. 8. Stergiopulos N, Spiridon M, Pythoud F, et al. On the wave transmission and reflection properties of stenoses. J Biomech. 1996;29:31–38. 9. Huang W, Tian Y, Gao J, et al. Comparison of theory and experiment in pulsatile flow in cat lung. Ann Biomed Eng. 1998;26:812–820. 10. Segers P, Verdonck P. Role of tapering in aortic wave reflection: hydraulic and mathematical model study. J Biomech. 2000;33:299–306. Figure 4. Diagram showing median distal and proximal PVPIs. Horizontal bars above and below median boxes represent maxi- mal and minimal values of PVPI. Figure 5. Diagram depicting inverse correlation between PVPI and vessel diameter. Zielinsky et al Fetal Pulmonary Vein Diameter and Flow Dynamics 2379
  8. 8. 11. Hole T, Urheim S, Skjaerpe T. Intra- and inter-observer reproducibility of transthoracic pulmonary venous Doppler flow indices after acute myo- cardial infarction. Eur J Echocardiogr. 2002;3:32–38. 12. Yazar F, Ozdogmus O, Tuccar E, et al. Drainage patterns of middle lobe vein of right lung: an anatomical study. Eur J Cardiothorac Surg. 2002; 22:717–720. 13. Hall SM, Hislop AA, Pierce CM, et al. Prenatal origins of human intrapulmonary arteries: formation and smooth muscle maturation. Am J Respir Cell Mol Biol. 2000;23:194–203. 14. Fasouliotis SJ, Achiron R, Kivilevitch Z, et al. The human fetal venous system: normal embryologic, anatomic, and physiologic characteristics and developmental abnormalities. J Ultrasound Med. 2002;21: 1145–1158. 15. DeMello DE, Reid LM. Embryonic and early fetal development of human lung vasculature and its functional implications. Pediatr Dev Pathol. 2000;3:439–449. 16. Hislop AA. Airway and blood vessel interaction during lung devel- opment. J Anat. 2002;201:325–334. 17. Hall SM, Hislop AA, Haworth SG. Origin, differentiation, and maturation of human pulmonary veins. Am J Respir Cell Mol Biol. 2002;26:333–340. 18. Blom NA, Gittenberger-de-Groot AC, Jongeneel TH, et al. Normal devel- opment of the pulmonary veins in human embryos and formulation of a morphogenetic concept for sinus venosus defects. Am J Cardiol. 2001; 87:305–309. 19. Webb S, Kanani M, Anderson RH, et al. Development of the human pulmonary vein and its incorporation into the morphologically left atrium. Cardiol Young. 2001;11:632–642. 20. Appleton CP. Hemodynamic determinants of Doppler pulmonary venous flow velocity components: new insights from studies in lightly sedated normal dogs. J Am Coll Cardiol. 1997;30:1562–1574. 21. Barbier P, Solomon S, Schiller NB, et al. Determinants of forward pulmonary vein flow: an open pericardium pig model. J Am Coll Cardiol. 2000;35:1947–1959. 22. Talbert DG, Johnson P. The pulmonary vein Doppler flow velocity waveform: feature analysis by comparison of in vivo pressures and flows with those in a computerized fetal physiological model. Ultrasound Obstet Gynecol. 2000;16:457–467. 23. Smiseth OA, Thompson CR, Lohavanichbutr K, et al. The pulmonary venous systolic flow pulse: its origin and relationship to left atrial pressure. J Am Coll Cardiol. 1999;34:802–809. 24. Rajagopalan B, Friend JA, Stallard T, et al. Blood flow in pulmonary veins, I: studies in dog and man. Cardiovasc Res. 1979;13:667–676. 25. Rajagopalan B, Friend JA, Stallard T, et al. Blood flow in pulmonary veins, II: the influence of events transmitted from the right and left sides of the heart. Cardiovasc Res. 1979;13:677–683. 26. Rajagopalan B, Bertram CD, Stallard T, et al. Blood flow in pulmonary veins, III: simultaneous measurements of their dimensions, intravascular pressure and flow. Cardiovasc Res. 1979;13:684–692. 27. Hellevik LR, Segers P, Stergiopulos N, et al. Mechanism of pulmonary venous pressure and flow waves. Heart Vessels. 1999;14:67–71. 28. Lakshminrusimha S, D’Angelis CAD, Russell JA, et al. C-type natriuretic peptide system in fetal ovine pulmonary vasculature. Am J Physiol Lung Cell Mol Physiol. 2001;281:L361–L368. 29. Rossi A, Loredana L, Cicoira M, et al. Additional value of pulmonary vein parameters in defining pseudonormalization of mitral inflow pattern. Echocardiography. 2001;18:673–679. 30. Graziano JN, Heidelberger KP, Ensing GJ, et al. The influence of a restrictive atrial septal defect on pulmonary vascular morphology in patients with hypoplastic left heart syndrome. Pediatr Cardiol. 2002;23: 146–151. 31. Lenz F, Machlitt A, Hartung J, et al. Fetal pulmonary venous flow pattern is determined by left atrial pressure: report of two cases of left heart hypoplasia, one with patent and the other with closed interatrial commu- nication. Ultrasound Obstet Gynecol. 2002;19:392–395. 32. Yalcin F, El-Amrousy M, Muderrisoglu H, et al. Pulmonary venous flows reflect changes in left atrial hemodynamics during mitral balloon val- votomy. Angiology. 2002;53:323–327. 33. Palazzuoli A, Puccetti L, Pastorelli M, et al. Transmitral and pulmonary venous flow study in elite male runners and young adults. Int J Cardiol. 2002;84:47–51. 34. Yang H, Jones M, Shiota T, et al. Pulmonary venous flow determinants of left atrial pressure under different loading conditions in a chronic animal model with mitral regurgitation. J Am Soc Echocardiogr. 2002:15(10 pt 2):1181–1218. 35. Ito T, Harada K, Takada G. Changes in pulmonary venous flow patterns in patients with ventricular septal defect. Pediatr Cardiol. 2002;23: 491–495. 2380 Circulation November 11, 2003
  9. 9. Clinical Investigation Comparison of Left Ven- tricular Electromechanical Mapping and Left Ventricular Angiography Defining Practical Standards for Analysis of NOGA™ Maps We performed this prospective cohort study to correlate the findings of left ventricular angiography (LVA) and NOGA™ left ventricular electromechanical mapping (LVEM) in the evaluation of cardiac wall motion and also to establish standards for wall motion assess- ment by LVEM. Fifty-five patients (35 men; mean age, 60.4 ± 11.8 years) eligible for elec- tive left cardiac catheterization underwent LVA and LVEM. Wall motion scores, LV ejection fractions (LVEF), and LV volumes derived from LVA versus LVEM data were compared and analyzed statistically. Receiver operating characteristic (ROC) curves were used to assess the accuracy of LVEM in distinguishing between normal, hypoki- netic, and akinetic/dyskinetic wall motion. Mean LVEM procedure time was 37 ± 11 min- utes. The LVEM and LVA findings differed for mean LVEF (55% ± 13% vs 36% ± 9%), mean end-systolic volume (56 ± 13 mL vs 36 ± 10 mL), and mean end-diastolic volume (174 ± 104 mL vs 123 ± 65 mL). Mean wall motion scores (± SD) for normokinetic, hypo- kinetic, and akinetic/dyskinetic segments were 13.9% ± 5.6%, 8.3% ± 5.2%, and 3.2% ± 3.1%, respectively. Cutpoints for differentiating between wall motion types were 12% and 6%. The ROC curves showed LVEM to have a 93% accuracy in differentiating be- tween normokinetic and akinetic/dyskinetic segments and a 73% accuracy between normokinetic and hypokinetic segments. These data suggest that LVEM can differenti- ate between normal and abnormal cardiac wall motion, although it is more accurate at differentiating between normokinetic and akinetic/dyskinetic motion than between normokinetic and hypokinetic motion. (Tex Heart Inst J 2003;30:19-26) eft ventricular electromechanical mapping (LVEM) using NOGA™ soft- ware (Biosense-Webster; Diamond Bar, Calif) is a new technology that re- constructs 3-dimensional maps of the left ventricle (LV) from data acquired at multiple points on the endocardium. The NOGA software is used to compare the location of an endocardial point in systole and diastole and calculate its move- ment in relation to other surrounding points. This movement is expressed as linear local shortening (LLS), which is a validated measure of myocardial mechanical function.1-3 Through reconstruction of the LV endocardial contour, the system has the capability to provide hemodynamic data such as LV ejection fraction, end- systolic volume, and end-diastolic volume.4 Left ventricular angiography (LVA) was the 1st method used to assess LV wall motion contractility and hemodynamic parameters.5,6 Other methods used for this purpose now include 2- and 3-dimensional (2-D and 3-D) echocardiography, ra- dionuclide ventriculography, computed tomography, and magnetic resonance imaging.7 Left ventricular angiography is still widely used for LV assessment and re- mains one of the gold standards for wall motion analysis. Previous studies have demonstrated a moderate correlation between LVEM and LVA in terms of global and regional contractile LV function and volume measure- ments.8-10 To determine whether this correlation remains valid for LVEM findings obtained with use of a newer version of the NOGA software (v. 4.0), which in- corporates a different LLS algorithm, we analyzed and correlated the findings of LVEM and LVA in a prospective cohort study. In addition, as the primary end point, we sought to establish standard values for wall motion assessment (in com- Rogerio Sarmento-Leite, MD, PhD Guilherme V. Silva, MD Hans F.R. Dohman, MD Ricardo Mourilhe Rocha, MD Hans J.F. Dohman, MD Nelson Durval S.G. de Mattos, MD Luis Antonio Carvalho, MD Carlos A.M. Gottschall, MD Emerson C. Perin, MD, PhD Key words: Angiography; diagnostic imaging/ instrumentation; electro- mechanical mapping; electrophysiology/methods; heart/anatomy/physiology; heart catheterization; heart ventricle/physiology; imaging processing, computer- assisted From: Texas Heart Institute at St. Luke’s Episcopal Hospital (Drs. Perin, Sarmento-Leite, and Silva), Houston, Texas; Hospital Pro-Cardíaco (Drs. Carvalho, de Mattos, F.R. Dohman, J.F. Dohman, and Rocha), Rio de Janeiro, Brazil; and Instituto de Cardiologia do Rio Grande do Sul (Dr. Gottschall), Porto Alegre, Brazil Address for reprints: Emerson C. Perin, MD, 6624 Fannin, Suite 2220, Houston, TX 77030 E-mail: eperin@crescentb.net © 2003 by the Texas Heart ® Institute, Houston Texas Heart Institute Journal Comparison of LV Electromechanical Mapping and LV Angiography 19 L
  10. 10. parison with LVA findings) that can be used routinely in the analysis of LV electromechanical maps. Patients and Methods Study Design and Inclusion Criteria We conducted a cohort prospective study of 55 pa- tients who underwent mapping procedures after elec- tive left cardiac catheterization at 2 centers (Texas Heart Institute, Houston, Texas; and Hospital Pro- Cardíaco, Rio de Janeiro, Brazil). Electromechanical mapping was performed after LVA. The LVEM proce- dures were performed only in patients who were clini- cally stable; excluded were those patients who had severe peripheral vascular disease, atrial fibrillation, aortic stenosis, suspected thrombus in the left ventri- cle, or acute myocardial infarction. The study protocol was approved by the ethics committees of both hospi- tals. There was no industry support for this study. The procedures were explained, and informed written con- sent was obtained from all patients before they were enrolled in the study. NOGA Mapping System andTechnique A NOGA electromechanical map of the left ventricle is constructed by the acquisition of a series of points at multiple locations on the LV endocardial surface gated to a surface electrocardiogram. NOGA LVEM uses ultra-low magnetic fields (10-5 –10-6 tesla) that are generated by a triangular magnetic pad positioned be- neath the patient. The intersection of the magnetic fields with a location sensor just proximal to the de- flectable tip of a 7F mapping catheter helps to deter- mine the location and orientation of the catheter tip inside the left ventricle. An algorithm is used by the NOGA system to calculate and analyze the movement of the catheter tip or the location of an endocardial point throughout systole and diastole. That move- ment is then compared with the movement of neigh- boring points in an area of interest. The resulting value, which is called linear local shortening (LLS) and is expressed as a percentage, is representative of the mechanical function of the left ventricle at that point. Data points are obtained only when the catheter tip is in stable contact with the endocardium. This contact is determined automatically by the NOGA system using the following criteria: 1) point loop sta- bility (LS), defined as the trajectory of a specific point during 2 consecutive cardiac cycles (a low value, in- dicating good-quality data, is preferable); 2) cycle length (CL) stability, defined as the difference between the CL of a specific point and the average CL of the previously recorded 100 beats; 3) local activation time (LAT) stability, defined as the difference between the LAT of a point and the LATs of points previously re- corded (variation should be no more than 3 ms); and 4) location stability (LcS), defined as the variability in the location of the catheter tip during the cardiac cycle (between end systole and end diastole). The mapping catheter also incorporates electrodes that measure en- docardial electrical signals (unipolar or bipolar volt- age). Voltage values are assigned to each point acquired during mapping of the LV, and an electrical map is constructed. Each data point has an LLS value and a voltage value. When the map is complete, all the data points are integrated by the NOGA workstation and are presented in a 3-D color-coded reconstruction of the endocardial surface, and in 9- and 12-segment bull’s-eye views that show average values for LLS and voltage data in each segment (Fig. 1). These maps can be spatially manipulated in real time on a Silicon Graphics workstation (Mountain View, Calif). The 3-D representations acquired during the cardiac cycle are used to calculate LV volumes. The NOGA system uses the largest volume as the end-diastolic vol- ume (EDV) and the smallest volume as the end-sys- tolic volume (ESV). The LV ejection fraction (LVEF) is calculated as (EDV – ESV)/EDV. The NOGA sys- tem also uses, as predetermined by the operator, a tri- angle fill threshold (FT) that determines the extent to which the computer algorithm will interpolate data into (or “fill in”) the space between adjacent points. In the present study, a triangle FT of 15 mm was used (the standard recommended by the manufacturer to ensure map completeness). After the acquisition of points, postprocessing analysis is performed with a se- ries of filters in the moderate setting to eliminate inner points, points that do not fit the standard stability cri- teria (LcS <4 mm; LS <6 mm; and CL <10%), points acquired during ST-segment elevation, and points not related to the left ventricle (for example, those on the atrium). Volume 30, Number 1, 200320 Comparison of LV Electromechanical Mapping and LV Angiography Fig. 1 A representative, 3-dimensional, color-coded recon- struction of the endocardial surface (left) and 9- and 12- segment bull’s-eye views (right top and bottom, respectively). LLS = linear local shortening
  11. 11. Left Ventricular Angiography Protocol Left ventricular angiography was performed through the femoral approach using a 5F pigtail catheter (Cor- dis; Miami Lakes, Fla), which was marked at 1-cm intervals for accurate calculation of the LV volumes and LVEFs according to the area-length formula.11 All LVAs were obtained in 2 planes—a 30° right anterior oblique (RAO) view and a 60° left anterior oblique (LAO) view—during a period of stable sinus rhythm. Ventricular volume was not measured during or after a premature beat. Wall motion was evaluated in the RAO view by 2 independent experienced observers. Segments visible in the angiographic RAO view (that is, anterobasal, anteromedial, apical, inferomedial, and posterobasal) were compared with the corresponding 5 segments of the LVEM bull’s-eye view. Wall motion in each myocardial segment was scored as follows: 0 = dyskinetic; 1 = akinetic; 2 = hypokinetic; and 3 = nor- mokinetic. Left Ventricular Electro- mechanical Mapping Protocol Left ventricular electromechanical mapping was per- formed as follows. All patients were heparinized (70 U/kg) after biplane LVA and before LVEM. The map- ping catheter curve (B, D, or F) was selected on the basis of LV size. The catheter (7F) was advanced un- der fluoroscopic guidance to the descending thoracic aorta, where its tip was fully deflected and then subse- quently advanced around the aortic arch and across the aortic valve into the left ventricle. Inside the left ventricle, the deflection was relaxed and the catheter tip was oriented toward the LV apex. The initial data point was acquired at the LV apex, and 2 points were acquired—one at the base of the septum and one at the lateral wall—to complete an initial triangle defin- ing the borders of the LV. Subsequent points were ac- quired until all endocardial segments were uniformly sampled (ideally, 3 points in each of 12 segments, according to the NOGA™ Mapping Excellence Pro- gram*). Each data point was filtered on-line, immedi- ately after acquisition, and during postprocessing analysis with use of the parameters described above. Map Analysis The LVEMs were analyzed using data on the mechan- ical function of the myocardium (LLS), which has been extensively validated in previous studies.1-3 The data from the maps were compared with data ob- tained by angiography. Angiography provides a 2-D image of the left cardiac chamber that historically has been compared with images produced by emerging technologies such as echocardiography, radionuclide studies, and MRI.7 To compare wall motion as represented by LVEM versus LVA, the anterobasal, anteromedial, apical, in- feromedial, and posterobasal segments on the RAO angiogram (Fig. 2) were matched with those on the corresponding 5 segments of the 9-segment LVEM bull’s-eye view. (Again, according to the NOGA™ Mapping Excellence Program, each LVEM segment should contain at least 3 points after initial filtering and postprocessing analysis.) The segments were di- vided into 3 groups according to wall motion score: Group I (0 or 1, akinetic or dyskinetic); Group II (2, hypokinetic); and Group III (3, normokinetic). Texas Heart Institute Journal Comparison of LV Electromechanical Mapping and LV Angiography 21 ∗ The NOGA™ Mapping Excellence Program was created by Biosense-Webster in order to verify and ensure the quality of NOGA maps. It has been developed and implemented by the authors in conjunction with Biosense-Webster. Fig. 2 Schematic illustrations show the 5 myocardial segments evaluated by left ventricular angiography and left ventricular electromechanical mapping (top) and corresponding bull’s-eye view (bottom) for comparison. AB = anterobasal; AM = anteromedial; Ap = apical; IM = infero- medial; PB = posterobasal
  12. 12. LVA, compared, and classified into 3 groups. Group I (akinetic/dyskinetic) comprised 9 segments; Group II (hypokinetic), 68 segments; and Group III (normo- kinetic), 198 segments. Table III shows the mean LLS (± SD) values for each group. Using discriminant analysis, the cutpoints for differentiation between nor- mokinetic, hypokinetic, and akinetic/dyskinetic seg- ments by LLS were set at 12% and 6% (Table IV). As shown by ROC curves (Figs. 9 and 10), the LLS val- ues determined by LVEM had an accuracy of 93% in differentiating between normokinetic and akinetic/ dyskinetic myocardial segments and an accuracy of 73% in differentiating between normokinetic and hy- pokinetic myocardial segments. Statistical Analysis Left ventricular ejection fraction and volume data were presented as the mean ± standard deviation (SD). The mean values obtained by LVEM and LVA were com- pared using the unpaired Student’s t-test. A P value of <0.5 was considered significant for all comparisons. Correlation coefficients were reported in terms of the Pearson correlation index (r), and correction index- es for each variable were created. The Bland-Altman technique was used to determine the agreement be- tween continuous measurements acquired by LVEM and LVA. For each group of wall motion scores, the mean LLS (± SD) was determined. Boundaries for classification of wall motion as normal, hypokinetic, and akinetic/dyskinetic were derived by discriminant analysis. This analytic technique finds the 2 bound- aries that predict classification into a group (in this case, 1 of the 3 groups determined by LVEM wall mo- tion score). The Scheffé test was also used for multiple comparisons of wall motion. Receiver operating char- acteristic (ROC) curves were used to assess the sensi- tivity and specificity of LVEM for distinguishing between normokinetic and hypokinetic and between normokinetic and akinetic/dyskinetic wall motion. Results The study population consisted of 55 consecutive pa- tients who were scheduled for elective left heart catheterization, during which LVEM was performed (Table I). The mean age was 60.4 ± 11.8 years (range, 42–86 years), and there were more men (35 [64%]) than women. The average LVEM procedure time was 37 ± 11 minutes. After application of a moderate automatic filter, a mean of 62 ± 12 points was ob- tained in each mapping to render a representative 3- D reconstruction of the LV. There were no deaths or major complications associated with LVEM (such as malignant ventricular arrhythmias or LV perforation requiring pericardiocentesis). One patient had a left ventricular perforation that resulted in a small post- procedural pericardial effusion. This complication was managed conservatively and was followed with serial echocardiography until it resolved; pericardiocentesis was not necessary. The mean values for EF, EDV, and ESV, obtained by LVEM and LVA, are shown in Table II. The Pear- son correlation index and graphs for each variable are shown in Figs. 3–5. A moderate-to-good correlation was found between LVEM and LVA findings; how- ever, as shown by Bland-Altman analysis (Figs. 6–8), clinical disagreement and lack of interchangeability was found between all measured parameters for both methods. In the 55 cases studied, the wall motion scores in a total of 275 segments were determined by LVEM and Volume 30, Number 1, 200322 Comparison of LV Electromechanical Mapping and LV Angiography TABLE I. Characteristics of 55 Patients at Baseline No. of Patient Characteristic Pts. (%) Mean age (y) 60.4 ± 11.8* Sex Male 35 (64) Female 20 (36) History Diabetes 11 (20) Hypertension 36 (65) Smoking 27 (49) Hyperlipidemia 41 (75) Myocardial infarction 25 (45) Cerebral vascular disease 4 (7) Peripheral vascular disease 5 (9) Bypass graft 19 (35) PTCA 27 (49) Mean LV ejection fraction 55% ± 13%* Associated procedures Diagnostic catheterization 33 (60) DMR 2 (4) PCI 20 (36) *Mean ± SD DMR = direct myocardial revascularization; LV = left ventricular; PCI = percutaneous coronary intervention; PTCA = percutane- ous transluminal coronary angioplasty TABLE II. Mean Values for LVA and LVEM Findings Cardiac Component LVA LVEM Ejection fraction (%) 55 ± 13 36 ± 9 End-diastolic volume (mL) 174 ± 104 123 ± 65 End-systolic volume (mL) 56 ± 13 36 ± 10 All data are presented as mean ± SD. LVA = left ventricular angiography; LVEM = left ventricular electromechanical mapping
  13. 13. Fig. 3 Pearson correlation index for ejection fraction (EF) as determined by left ventricular angiography (LVA) and left ventricular electromechanical mapping (LVEM). Fig. 4 Pearson correlation index for end-diastolic volume (EDV) as determined by left ventricular angiography (LVA) and left ventricular electromechanical mapping (LVEM). Fig. 5 Pearson correlation index for end-systolic volume (ESV) as determined by left ventricular angiography (LVA) and left ventricular electromechanical mapping (LVEM). Fig. 6 Bland-Altman association for ejection fraction (EF) as determined by left ventricular angiography (LVA) and left ventricular electromechanical mapping (LVEM). Fig. 7 Bland-Altman association for end-diastolic volume as (EDV) determined by left ventricular angiography (LVA) and left ventricular electromechanical mapping (LVEM). Fig. 8 Bland-Altman association for end-systolic volume (ESV) as determined by left ventricular angiography (LVA) and left ventricular electromechanical mapping (LVEM). Texas Heart Institute Journal Comparison of LV Electromechanical Mapping and LV Angiography 23
  14. 14. Discussion The present study was designed to compare the as- sessment of global and regional function of the left ventricle by 2 different techniques: LVEM and LVA. Both techniques are invasive and yield quantitative and qualitative information about the performance of the left ventricle. However, LVEM creates an on- line, real-time 3-D reconstruction of the endocardial surface and has proven value for assessing both myo- cardial viability12 and the mechanical function of myo- cardial segments. Several studies have focused on the ability of LVEM to distinguish between normal and infarcted myo- cardium, to enable comparison of hemodynamic parameters, and to perform wall motion analysis. Nonetheless, no practical cutpoints for LVEM analy- sis of wall motion had previously been established.8-10 Therefore, as the primary end point of a study of the largest LVEM cohort in the literature, we have corre- lated the findings of LVEM and LVA by analyzing only those LVEM segments that were also well visual- ized by LVA and well matched to the same regions of the LVEM bull’s-eye views. The values used to define wall motion in the pres- ent study were similar to those already described in the literature. However, the mean values (± SD) that we established for normokinetic, hypokinetic, and akinetic/dyskinetic wall motion (13.9% ± 5.6%, 8.3% ± 5.2%, and 3.2% ± 3.1%, respectively) over- lapped and sometimes made it difficult to differen- TABLE III. Wall Motion Classification and Mean LLS Values Wall Motion Segments LLS Pattern (n = 275) (%) Group I - Akinetic/dyskinetic 9 3.2 ± 3.1 Group II - Hypokinetic 68 8.3 ± 5.2 Group III - Normokinetic 198 13.9 ± 5.6 Data are presented as mean ± SD. P <0.05 for all comparisons. LLS = linear local shortening TABLE IV. Cutpoints for Differentiation of Wall Motion by LLS According to Discriminant Analysis Wall Motion Pattern LLS (%) Group I - Akinetic/dyskinetic <6% Group II - Hypokinetic ≥6% or <12% Group III - Normokinetic ≥12% LS = linear local shortening Fig. 9 Receiver operating characteristic curve for the differ- entiation between normokinetic and akinetic/dyskinetic seg- ments by local linear shortening (LLS). Area under the curve = 0.93; threshold <6%; sensitivity, 89%; specificity, 88% Fig. 10 Receiver operating characteristic curve for the differ- entiation between normokinetic and hypokinetic segments by local linear shortening (LLS). Area under the curve = 0.73; threshold <12%; sensitivity, 68%; specificity, 62% tiate between normokinetic and hypokinetic tissue. This was well exemplified by the ROC curve (Fig. 10), which showed a weak accuracy of 73%. These find- ings agree with the data of Lessick and colleagues,13 who compared echocardiography with LVEM data and reported an accuracy of 69%. On the other hand, our cutpoints allowed excellent differentiation be- tween normokinetic and akinetic/dyskinetic myo- cardial areas, with an accuracy of 93% (Fig. 9). Volume 30, Number 1, 200324 Comparison of LV Electromechanical Mapping and LV Angiography
  15. 15. demarcation of appropriate “target” zones for treat- ment is one of the keys to the success of our proce- dure. Therefore, by defining practical LLS thresholds for assessing mechanical activity in the present study, we believe we have made it easier to target viable myo- cardium (that is, tissues with low LLS and preserved electrical activity) using the NOGA system and so op- timize therapy. Moreover, even though the system is somewhat limited in its ability to differentiate wall motion, this limitation appears to be restricted to se- verely dilated or very hypertrophic ventricles. In such cases, performing a complete LVEM is already tech- nically challenging. We believe that this limitation can be overcome by devising mapping procedures that are more careful and detailed. In conclusion, our data indicate that there is a mod- erate correlation between LVA and LVEM findings and that LVEM can differentiate between normal and abnormal cardiac wall motion. However, it appears that LVEM is severely limited in its ability to measure LV hemodynamics, which will limit its widespread use for this purpose. Nevertheless, our findings are important, because they add to the current knowledge about the interpretation of LVEM findings, and be- cause they have important implications for the use of LVEM in conjunction with intramyocardial therapies in which optimal treatment delivery requires the accu- rate targeting of viable (normokinetic) versus nonvi- able (akinetic/dyskinetic) segments. References 1. Ben-Haim SA, Osadchy D, Schuster I, Gepstein L, Hayam G, Josephson ME. Nonfluoroscopic, in vivo navigation and mapping technology. Nat Med 1996;2:1393-5. 2. Gepstein L, Hayam G, Ben-Haim SA. A novel method for nonfluoroscopic catheter-based electromechanical mapping of the heart. In vitro and in vivo accuracy results. Circula- tion 1997;95:1611-22. 3. Smeets JL, Ben-Haim SA, Rodriguez LM, Timmermans C, Wellens HJ. New method for nonfluoroscopic endocardial mapping in humans: accuracy assessment and first clinical results. Circulation 1998;97:2426-32. 4. Gepstein L, Hayam G, Shpun S, Ben-Haim SA. Hemody- namic evaluation of the heart with a nonfluoroscopic elec- tromechanical mapping technique. Circulation 1997;96: 3672-80. 5. Dodge HT, Sandler H, Baxley WA, Hawley RR. Usefulness and limitations of radiographic methods for determining left ventricular volume. Am J Cardiol 1966;18:10-24. 6. Viamonte M Jr. Innovations in angiography. Radiol Clin North Am 1971;9:361-8. 7. Greenberg SB, Sandhu SK. Ventricular function. Radiol Clin North Am 1999;37:341-59,vi. 8. Bossi I, Black AJ, Choussat R, Cassagneau B, Farah B, La- borde JC, et al. Biosense NOGA electro-mechanical mapping accurately predicts left-ventricular wall motion at cineven- triculography [abstract]. Am J Cardiol 1999;84(6A):95P. 9. Thambar ST, Sharaf BL, Miele NJ, Williams DO. Assess- ment of global and regional wall motion by NOGA three- dimensional electro-mechanical mapping: a correlation The discrepancy in accuracy of differentating be- tween normokinetic and hypokinetic tissue and be- tween normokinetic and akinetic/dyskinetic tissue may be due to several factors. First, it can be very dif- ficult in some cases, especially in dilated or very hy- pertrophic ventricles, to perform a complete LVEM because the catheter cannot uniformly reach all areas of the left ventricle. As a result, mapping may be in- complete, and the average of the mapped values for a determined region may be misrepresented. Second, data suggesting low contractility of basal areas of the LV may in part represent the presence of fibrous tissue in perivalvular areas. Future development of LVEM in terms of performance and analysis may improve upon the completeness of mapping and make the interpre- tation of the data more accurate. As shown in a recent study by Van Langenhove and coworkers,14 the hemodynamic data obtained by LVEM has its limitations. In their study, the correla- tion between ESV and EF measurements obtained by LVEM versus LVA was moderate (r = 0.67 and r = 0.78, respectively), and the correlation between EDV measurements was poor (r = 0.40).14 These results dif- fer somewhat from ours, which showed better corre- lations for measurements of ESV (r = 0.81) and EDV (r = 0.71) and a worse correlation for measurements of EF (r = 0.56). Except for this difference, the results of our Bland-Altman analysis and the results from Van Langenhove’s study were similar, demonstrating that the dispersion of values is great and that the real clini- cal application of EDV and EF measurements sup- plied by LVEM is questionable, even when correction formulas are applied. Therefore, we do not advocate the routine use of the NOGA method as an alterna- tive to other established methods for assessing LVEF. Similar problems with overlap of wall motion val- ues obtained by LVEM have been found in other se- ries.8-10,15 For example (although their comparison was between the findings of LVEM and nuclear perfusion studies), Kornowski’s group12 recorded normal and ab- normal LLS values (normal, 12.5% ± 2.8%; abnor- mal, 3.4% ± 3.4%), that were very similar to ours in the present study (normal, 13.9% ± 5.6%; abnormal, 3.2% ± 3.1%). Despite its limitations, LVEM may assume an im- portant role in new therapies that directly target isch- emic heart disease. Such therapies aim to promote angiogenesis or restore contractility through the trans- plantation of stem cells16 and myoblasts17,18 or by injec- tion of growth factors.19 The future success of these and similar therapies depend profoundly on carefully controlled clinical trials that apply appropriate meth- ods and end points. In that regard, the NOGA map- ping system has an advantage over other potential therapeutic delivery systems (especially those involv- ing surgery), because it is less invasive. In theory, the Texas Heart Institute Journal Comparison of LV Electromechanical Mapping and LV Angiography 25
  16. 16. with the “gold standard” contrast left ventriculogram. Cir- culation 1999;100(18):I-23. 10. Van Langenhove G, Smits PC, Serrano P, Kosuma K, Kay IP, Albertal M, et al. Assessment of regional LV wall mo- tion: a comparison between computerized LV angiography and nonfluoroscopic electromechanical mapping. Circula- tion 1999;100(18):I-725. 11. Kennedy JW, Trenholme SE, Kasser IS. Left ventricular vol- ume and mass from single-plane cineangiocardiogram. A comparison of anteroposterior and right anterior oblique methods. Am Heart J 1970;80:343-52. 12. Kornowski R, Hong MK, Leon MB. Comparison between left ventricular electromechanical mapping and radionu- clide perfusion imaging for detection of myocardial viabili- ty. Circulation 1998;98:1837-41. 13. Lessick J, Smeets JL, Reisner SA, Ben-Haim SA. Electro- mechanical mapping of regional left ventricular function in humans: comparison with echocardiography. Cathet Car- diovasc Interv 2000;50:10-8. 14. Van Langenhove G, Hamburger JN, Smits PC, Albertal M, Onderwater E, Kay IP, Serruys PW. Evaluation of left ven- tricular volumes and ejection fraction with a nonfluoroscop- ic endoventricular three-dimensional mapping technique. Am Heart J 2000;140:596-602. 15. Keck A, Schwartz Y, Bahlmann E, Kuchler R, Kitzing R, Schluter M, Kuck KH. Assessment of regional left ventricu- lar contractility: comparison between NOGATM electrome- chanical mapping and echocardiography [abstract]. J Am Coll Cardiol 1999;33(2 Suppl A):442A. 16. Orlic D, Kajstura J, Chimenti S, Jakoniuk I, Anderson SM, Li B, et al. Bone marrow cells regenerate infarcted myocar- dium. Natuare 2001;410:701-5. 17. Taylor DA, Atkins BZ, Hungspreugs P, Jones TR, Reedy MC, Hutcheson KA, et al. Regenerating functional myo- cardium: improved performance after skeletal myoblast trans- plantation [erratum appears in Nat Med 1998;4:1200]. Nat Med 1998;4:929-33. 18. Menasche P, Hagege AA, Scorsin M, Pouzet B, Desnos M, Duboc D, et al. Myoblast transplantation for heart failure. Lancet 2001;357:279-80. 19. Freedman SB, Isner JM. Therapeutic angiogenesis for coro- nary artery disease. Ann Intern Med 2002;136:54-71. Volume 30, Number 1, 200326 Comparison of LV Electromechanical Mapping and LV Angiography
  17. 17. Impact of renal denervation on renal content of GLUT1, albuminuria and urinary TGF-h1 in streptozotocin-induced diabetic rats Beatriz D’Agord Schaana,*, Silvia Lacchinib , Marcello Casaccia Bertolucic , Maria Cla´udia Irigoyend , Ubiratan Fabres Machadoe , Helena Schmidf a Instituto de Cardiologia do Rio Grande do Sul/FUC, Unidade de Pesquisa, Av. Princesa Isabel, 395 Santana, 90.620-001 Porto Alegre, RS, Brazil b Laborato´rio de Gene´tica e Cardiologia Molecular, Instituto do Coracßa˜o (InCor), HC-FMUSP, Universidade de Sa˜o Paulo, Sa˜o Paulo, SP, Brazil c Hospital de Clı´nicas de Porto Alegre, Porto Alegre, Brazil d Laborato´rio de Hipertensa˜o Experimental - Unidade de Hipertensa˜o, Instituto do Coracßa˜o (InCor), HC-FMUSP, Universidade de Sa˜o Paulo, Sa˜o Paulo, SP, Brazil e Departamento de Fisiologia, Instituto de Cieˆncias Biolo´gicas, Universidade de Sa˜o Paulo, Sa˜o Paulo, Brazil f Curso de Po´s-Graduacßa˜o da UFRGS, Hospital de Clı´nicas de Porto Alegre and FFFCMPA, Porto Alegre, Brazil Received 9 January 2002; received in revised form 30 October 2002; accepted 9 December 2002 Abstract In long-term diabetes mellitus, the progression of nephropathy has been related to the occurrence of autonomic neuropathy. This study was designed to evaluate the effects of bilateral denervation of the kidneys of streptozotocin-diabetic rats, an experimental model that presents diabetic nephropathy with increased abundance of cortical GLUT1 in the kidney and increased urinary excretion of albumin and transforming growth factor-h1 (TGF-h1). Twenty-four-hour urinary TGF-h1 (ELISA), urinary albumin (electroimmunoassay) and GLUT1 protein levels (Western blotting) in the renal cortex and medulla were evaluated in diabetic (n = 13) and control (n = 13) rats 45 days after streptozotocin injection, submitted or not to surgical renal denervation. Evaluations were performed 15 days after the surgery. The effects of renal denervation were confirmed by intra-renal decrease of norepinephrine levels. Mean arterial pressure did not differ between diabetic and control rats, whether they underwent renal denervation or not. Renal denervation increased cortical (6905 F 287, 3506 F 193, 4144 F 246 and 5204 F 516 AU in renal-denervated controls, controls, renal-denervated diabetics and diabetics, respectively) and medullar GLUT1 protein in control rats, but reverted the cortical GLUT1 protein rise determined by diabetes. Although kidney denervation in diabetic rats induced a decrease in cortical GLUT1 abundance toward normal levels, these levels did not reach those of normal animals. However, renal denervation did not determine any changes in urinary albumin and urinary TGF-h1 in both diabetic (127.3 F 12 Ag/24 h and 111.8 F 24 ng mgÀ 1 creatinine, respectively) and control rats (45.9 F 3 Ag/24 h and 13.4 F 4 ng mgÀ 1 creatinine, respectively). In conclusion, early-phase renal denervation in streptozotocin-diabetic rats produces a normalisation of previously elevated cortical GLUT1 protein content, but is not enough for reverting the increased urinary TGF-h1 and albuminuria of diabetes. D 2003 Elsevier Science B.V. All rights reserved. Keywords: Diabetes mellitus, experimental; Diabetes mellitus, nephropathies; Denervation; Transforming growth factors; Streptozotocin; Glucose transporters 1. Introduction In long-term diabetes mellitus, the progression of nephr- opathy has been related to the occurrence of autonomic neuropathy (Sundkvist and Lilja, 1993). The mechanisms involved are not well understood. Persistent immunoreactivity for transforming growth factor-h1 (TGF-h1) protein, a cytokine directly involved in extracellular matrix production, was previously demon- strated by us, in the glomeruli of streptozotocin-diabetic rats. The correlation of these results with the progressive albuminuria shown by these animals suggests that this polypeptide is involved in the genesis of rat diabetic glomerulosclerosis (Bertoluci et al., 1996). More recently, we showed, in the same animal model, that 45 days of experimental diabetes significantly increased urinary albu- min and urinary TGF-h1, as well as GLUT1 protein in the renal cortex, but not in the renal medulla. These findings suggest that higher cortical GLUT1 protein levels amplify the effects of hyperglycemia in determining higher intra- cellular glucose in mesangial cells, contributing to the 1566-0702/03/$ - see front matter D 2003 Elsevier Science B.V. All rights reserved. doi:10.1016/S1566-0702(02)00295-3 * Corresponding author. Tel.: +55-513-2232746; fax: +55-513- 2192802. E-mail addresses: pesquisa@cardnet.tche.br, bschaan.voy@terra.com.br (B. D’Agord Schaan). www.elsevier.com/locate/autneu Autonomic Neuroscience: Basic and Clinical 104 (2003) 88–94
  18. 18. kidney damage that complicates diabetes. This premature appearance of albuminuria and high urinary TGF-h1 in these experiments probably reflects the metabolic decom- pensation to which these animals were submitted, since they did not receive insulin (Schaan et al., 2001). In human diabetic nephropathy, high blood pressure levels determine deterioration of renal function. Glomerular hy- pertension, determining mechanical stretch, enhances extrac- ellular matrix formation by mesangial cells, which is aggra- vated in a milieu of high glucose concentration (Cortes et al., 1997). The cytokine TGF-h1 secreted by mesangial cells is probably involved in this process (Hirakata et al., 1997). Decreased renal vascular resistance induced by decreas- ing sympathetic nerve activity renders diabetes and hyper- tension-induced mesangial cell stretch unopposed (DiBona and Kopp, 1997). Since muscle denervation (another model of decreased sympathetic nerve activity) determines reduc- tion in GLUT4 mRNA and protein content in myocites, we hypothesised that renal denervation could induce changes in kidney glucose transporter content, consequently increasing glucose content of cortical cells like the mesangial, endo- thelial and/or epithelial kidney cells (Henriksen et al., 1991; Block et al., 1991). Even though the streptozotocin-diabetic rat develops characteristic glomerulosclerotic lesions similar to those found in human diabetic nephropathy, this animal model does not develop hypertension, making it a good model for evaluating the effects of denervation itself. No studies in the streptozotocin-diabetic rat model have explored whether autonomic dysfunction could determine the modifications of renal function that are implicated in the genesis of diabetic nephropathy. Since experimental diabetes requires 6–9 months to determine autonomic denervation of the gastrointestinal tract (Schmidt and Sharp, 1982), and also of the heart (Felten et al., 1982), and surgical renal denervation is a relatively simple and widely used procedure, we propose its utilisation in rats injected with streptozotocin in order to evaluate the effects of renal denervation on the diabetic kidney. The absence of hypertension in this model would allow us to study only the effects of autonomic innervation failure on renal function, independently of the effects of systemic hypertension on renal haemodynamics. Considering that the progression of nephropathy has been related to the occurrence of autonomic neuropathy, the aims of this study were to examine the effects of renal denervation upon mechanisms involved in the development of nephrop- athy like cortical GLUT1 and TGF-h1 production, as well as urinary albumin in the streptozotocin-diabetic rat. 2. Materials and methods 2.1. Animals Experiments were performed on male Wistar rats (Ani- mal Quarter House of the Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil) weighing 180–280 g. They were fasted overnight and rendered diabetic by a single injection in the tail vein of streptozotocin (60 mg kgÀ 1 ; Sigma, St. Louis, MO, USA) dissolved in citrate buffer (pH 4.5) and injected slowly. Controls were injected with citrate buffer. Animals were subsequently maintained for 30 days (diabetics: n = 13, controls: n = 13) in individual cages with free access to tap water and standard rat food. 2.2. Surgical renal denervation Thirty days after streptozotocin injection, a 24-h urinary sample was collected and bilateral renal denervation or sham surgery was performed in the four experimental groups: renal-denervated diabetic (n = 7), diabetic (n = 6), renal-denervated control (n = 5) and control (n = 8). Renal denervation was adapted as previously described and vali- dated in this laboratory (Oliveira et al., 1992; Lacchini et al., 1997). As widely described, renal denervation was accom- plished by using a surgical–pharmacological procedure (DiBona and Rios, 1980; Kassab et al., 1995; Granger et al., 1996; Huang et al., 1998; Lohmeier et al., 1998). Mechanical denervation was performed by carefully stripping all visible nerves at 16 Â magnification (M90 stereomicroscope, FD Vascocelos) along the renal arteries and veins from the aorta to the hilum of the kidney. Chemical denervation was performed by quickly painting the renal artery with 20% phenol in absolute ethanol. Then the artery was washed with isotonic saline. For sham denervation, the surgery was the same, but the renal artery and vein were not isolated and the nerves were left intact. Fifteen days later, another 24-h urinary sample was collected. The effectiveness of the procedure was determined by measuring renal tissue norepinephrine content, homoge- nising parts of the tissue in perchloric acid and, subsequently, assaying it using the alumina extraction procedure. Norepi- nephrine content of the renal homogenate was determined by high-performance liquid chromatography coupled with an electrochemical detector. Previous studies showed that this procedure markedly deplete the renal tissue norepinephrine to less than 5% in both kidneys (Granger et al., 1996; Lacchini et al., 1997). Surgical renal denervation determined a significant decrease in renal tissue norepinephrine content: 0.0131 pg mgÀ 1 PNC in renal-denervated control animals compared to 1.658 pg mgÀ 1 PNC in controls ( p < 0.05). 2.3. Arterial pressure measurement Catheters filled with saline were implanted under ether anesthesia into the femoral artery (PE-10) for direct meas- urement of arterial pressure. One day after catheter place- ment, the arterial cannula was connected to a strain-gauge transducer (P23Db, Gould-Statham, Oxnard, CA) and blood pressure signals were recorded during a 40-min period with a microcomputer equipped with an analog-to-digital con- verter board (CODAS, 2-kHz sampling frequency, Dataq B. D’Agord Schaan et al. / Autonomic Neuroscience: Basic and Clinical 104 (2003) 88–94 89
  19. 19. Instruments, Akron, OH). Rats were conscious and moved freely during the experiments. Recorded data were analysed on a beat-to-beat basis. Subsequently, blood was collected for plasma glucose measurement and the animals were anaesthetised in order to have the kidneys removed. 2.4. Renal sampling Anesthesia was performed with sodium pentobarbital (25 mg kgÀ 1 body weight, IV). Immediately after clamping the aorta up to the renal arteries, the abdominal aorta was isolated and catheterised below the renal arteries. After that, the inferior vena cava was cut below the renal veins. The kidneys were perfused with Hanks buffer and immediately removed. Renal cortex and medulla were dissected under ocular control; the tissue fragments of each area were weighed and frozen at À 70 jC for further procedures. 2.5. Measurements 2.5.1. Glucose, albumin and TGF-
  20. 20. 1 Plasma and urinary glucose were measured using the colorimetric enzymatic test (commercial kit, Merck, GE, Centrifichem System 400-Roche/Cobas Mira-Roche). Urinary albumin was quantified by electroimmunoassay using antibody anti-rat albumin as previously described (Schmid et al., 1989). For the TGF-h1 assay, immediately after collection, urinary samples were centrifuged at 2000 rpm for 5 min at room temperature and stored at À 80 jC. On the day of the assay, in order to activate latent TGF-h1, the samples were acidified with 1 N HCl to a pH of 2–3 for 30 min at room temperature, and then re-neutralised to pH 7–8 with the same amount of 1 N NaOH. The TGF-h1 was measured by using an enzyme-linked immunosorbent assay kit (TGF-h1 Emax k ImmunoAssay Systems-Promega, Madison, WI, USA) with a monoclonal antibody to human active TGF-h1 provided by the manufacturer as previously described (Schaan et al., 2001). Among the standards, the intra- and inter-assay coefficients were 6.9% and 12%, respectively. The reprodu- cibility of the assay was defined by measuring standards for 2 consecutive days: the correlation coefficient was 0.96. Recovery of samples between expected and apparent TGF- h1 concentrations after adding known amounts of TGF-h1 was 119%. The detection limit was 32 pg mlÀ 1 . The cross- reactivity with TGF-h2 was 1.6% and with TGF-h3 0.7%. Urinary TGF-h1 results were corrected by urinary creatinine and results expressed as ng mgÀ 1 of creatinine. 2.5.2. GLUT1 Renal cortex and medulla were analysed for their GLUT1 protein abundance. The antibody used was raised in New Zealand, white rabbits from a 15 amino acid peptide of rat GLUT1, which was synthesised according to the deduced carboxy-terminal sequence of rat GLUT1. It was coupled to keyhole limpet hemocyanin and used for immunisation of male New Zealand white rabbits. This anti-serum has been successfully used for immunoblotting (Vestri et al., 2001). The tissue samples were homogenised in 10 w/v buffer (10 mM Tris–HCl, 1 mM EDTA and 250 mM sucrose, pH 7.4, containing 5 mg/ml aprotinin), using a Polytron set at 24,000 rpm for 30 s, and centrifuged at 3000 Â g for 15 min. The supernatant was centrifuged at 12,000 Â g for 20 min, and the pellet was resuspended as a plasma membrane fraction, in which the alkaline phosphatase activity was shown to have increased more than three times compared to the enzyme activity in the supernatant of the first centrifugation. A Western blotting analysis was then per- formed as previously described (Vestri et al., 2001). The results were expressed as arbitrary units (AU) by amount of electrophoresed total protein. 2.6. Statistical analysis Data are reported as means F standard error of the mean. Statistical significance was calculated by the Student’s t-test for unpaired data when two groups were compared, and ANOVA (Student–Newman–Keuls as post-test) when four groups were compared. Urinary albumin and urinary TGF- h1 data were log10 transformed before analysis. Differences were considered to be significant for p < 0.05. 3. Results At baseline, body weights were similar in all experimen- tal groups: 250 F 4, 261 F11, 263 F 7 and 241 F11g, for Table 1 Characteristics of diabetic (D) and nondiabetic (ND) rats after 15 days of renal denervation (RD) (45 days after STZ injection) D D-RD ND ND-RD Body weight (g) 189 F 7* (7) 212 F 18* (6) 295 F 1 (6) 292 F 8 (7) Plasma glucose (mmol/l) 20.8 F 3* (7) 21.7 F 2* (5) 7.8 F 1 (6) 8.1 F1 (5) 24-h urinary glucose (mg/24 h) 2856 F 484*,# (12) 6064 F 1242* (8) 3.1 F 0.9 (10) 2.2 F 0.5 (10) Diuresis (ml/24 h) 59 F 6*,# (12) 86 F 7* (8) 20 F 1 (10) 24 F 10 (10) Mean arterial pressure (mmHg) 99 F 7 (5) 103 F 7 (4) 112 F 3 (4) 107 F 2 (4) Data are mean F S.E.M. Numbers in parenthesis indicate numbers of animals. *p < 0.05 vs. ND and ND-RD. # p < 0.05 vs. D-RD. B. D’Agord Schaan et al. / Autonomic Neuroscience: Basic and Clinical 104 (2003) 88–9490
  21. 21. renal-denervated control, control, renal-denervated diabetic and diabetic animals, respectively ( p = 0.13). The groups which received streptozotocin presented a slight loss of weight, whereas controls increased their body weights. Consequently, control rats were significantly heavier than diabetic rats at the end of the experiment ( p < 0.05). As expected, plasma glucose levels after 45 days of streptozo- tocin injection were elevated (by 2.5-fold) in diabetic rats when compared to control groups ( p < 0.05). Also, 24-h urinary glucose and diuresis were significantly higher in diabetic animals versus their controls, 30 and 45 days after streptozotocin injection. Therefore, these results confirmed the severity of the diabetic state obtained by the streptozo- tocin injection (Table 1). Renal denervation affected neither weight gain nor plasma glucose levels in either group, but it increased urinary glucose by 45% and diuresis by 68% in diabetics ( p < 0.05) (Table 1). Mean arterial pressure did not differ between diabetic and control rats (99 F 7 and 112 F 3 mm Hg, respectively), whether they underwent renal denervation or not (103 F 7 and 107 F 2 mm Hg, respectively). These data are shown in Table 1. Thirty days after streptozotocin injection, urinary albu- min was significantly higher in the diabetic group (212.3 F 47 vs. 73 F 5 Ag/24 h, p < 0.05). Fifteen days of renal denervation did not operate changes in albuminuria, neither between non-diabetic nor between diabetic animals (46 F 6, 89.1 F18, 127.3 F 19 and 141.3 F 24 Ag/24 h in renal-denervated control, control, renal-denervated diabetic and diabetic groups, respectively). These data are shown in Fig. 1. Fig. 2 shows that similar results were observed when urinary TGF-h1 was measured in the same urinary samples: 30 days of experimental diabetes determined higher levels of this polypeptide concentration, 71.1 F 9 vs. 10.8 F 2 ng/mg creatinine in diabetics and controls, respectively ( p < 0.05). Renal denervation did not determine any change in urinary TGF-h1, considering all groups (13.4 F 5, 10 F 4, 111.8 F 24 and 89.9 F 27 ng mgÀ 1 creatinine in renal- denervated control, control, renal-denervated diabetic and diabetic groups, respectively). Experimental diabetes and renal denervation in control animals determined higher levels of cortical GLUT1 protein independently ( p < 0.05 for each). However, renal denerva- tion in diabetic animals significantly reduced levels of cortical GLUT1 protein by 20% ( p < 0.05), in such a way that these levels were close to those of control animals Fig. 1. Albuminuria in control (ND) and diabetic (D) rats 30 days after STZ treatment (left) and 15 days later (right) after sham operation or renal denervation (RD). Data are mean F S.E.M. Besides the bars, n = indicates the number of animals. *p < 0.05 vs. ND; # p < 0.05 vs. ND-RD. Fig. 2. Urinary TGF-h1 in control (ND) and diabetic (D) rats, 30 days after STZ treatment (left) and 15 days later (right) after sham operation or renal denervation (RD). Cre = creatinine. Data are mean F S.E.M. Besides the bars, n = indicates the number of animals. *p < 0.05 vs. ND; # p < 0.05 vs. ND-RD. Fig. 3. Cortical (left) and medullar (right) GLUT1 protein content in nondiabetic (ND) and diabetic (D) rats submitted to sham operation or renal denervation (RD). Top, typical autoradiograms; bottom, data are mean F S.E.M. of four (cortex) or six animals (medulla). **p < 0.05 vs. ND and D- RD; y p < 0.05 vs. D. *p < 0.05 vs. ND, ND-RD and D; # p < 0.05 vs. ND-RD and ND. B. D’Agord Schaan et al. / Autonomic Neuroscience: Basic and Clinical 104 (2003) 88–94 91
  22. 22. (Fig. 3). Medullar levels of GLUT1 protein decreased by 50% in experimental diabetes ( p < 0.05). The effect of renal denervation in this group was reverse, but did not com- pletely restore GLUT1 protein levels to those observed in non-diabetic animals (Fig. 3). 4. Discussion An association between diabetic neuropathy and nephr- opathy has been suggested by a possible effect of denerva- tion in determining an enhancement of kidney vulnerability to the hemodynamic effects of blood pressure (Sundkvist and Lilja, 1993). In the streptozotocin-diabetic rat, albuminuria was related to progressively higher glomerular immunohis- tochemical TGF-h1 staining and deposition of total and type I collagen (Bertoluci et al., 1996), even though in this model there is no hypertension (Schaan et al., 1997), as it is observed in humans (Parving et al., 1981). In this animal model, renal diabetic damage is probably highly mediated by increased glucose utilisation in mesangial cells (Ayo et al., 1991). This increased glucose utilisation could be mediated by high levels of facilitative glucose transporters present on the cell surface of mesangial cells, since it is clear that the activity of these transporters may be a rate-limiting factor for increased glucose utilisation and consequently important in the development of diabetic changes in the kidney (Heilig et al., 1995). Despite the diuretic, natriuretic and hemodynamic effects of renal denervation and the kidney GLUT1 abun- dance currently described in many experimental conditions, they were not well defined in the streptozotocin-diabetic rat. The present study intended to observe the effects of renal denervation upon markers involved in the pathogenesis of diabetic nephropathy, such as the pattern of cortical GLUT1 expression, urinary albumin and urinary TGF-h1 in the experimental model of streptozotocin-diabetic rat. It is largely known that the effectiveness of renal dener- vation is determined by the reduction in norepinephrine renal tissue content (Kline and Mercer, 1980; Kassab et al., 1995; Granger et al., 1996; Lohmeier et al., 1998). Using these observations, we can consider that renal denervation in the present study was effective and clearly reduced the renal norepinephrine content in the animals submitted to the surgical procedure. In control animals, renal denervation determined, as diabetes also did, an elevation of cortical GLUT1 protein content. In diabetic animals, however, renal denervation significantly reduced levels of cortical GLUT1 protein, in such a way that these levels were almost identical to those of control animals. These effects could be explained by the possibility of cell damage or downregulation induced by glucotoxicity, since other authors, studying cells in culture, have observed elevation of GLUT1 expression and protein levels when the glucose medium content was increased (15–20 mmol lÀ 1 ), followed by reduction when glucose concentration was excessively increased (25–30 mmol lÀ 1 ) (Wakisaka et al., 1995; Knott et al., 1996). Nevertheless, even in the presence of downregulation of glucose trans- porters, other authors have demonstrated that the net glucose consumption by cultured glomerular cells remains substan- tially increased and is accompanied by a highly significant enhancement in types IV and VI collagen production (Wakisaka et al., 1994). In agreement with these authors, we observed a tendency to higher urinary TGF-h1 levels in these rats, indicating that the GLUT1 decrease determined by 15 days of denervation was not enough to decrease urinary TGF-h1 levels and, probably, neither the fibrosis process. In summary, renal denervation normalised previ- ously elevated cortical GLUT1 protein, but this change was not accompanied by reduced urinary TGF-h1 levels. More- over, it is important to emphasize that cortical GLUT1 expression had never been reported to be impaired in diabetes. Recently, some clinical studies emphasized the impor- tance of our findings regarding the potential role of GLUT1 overexpression in the pathogenesis of diabetic nephropathy. These studies demonstrated, in Chinese and Caucasoid diabetic patients, the association between polymorphisms of the glucose transporter GLUT1 gene and diabetic nephr- opathy (Liu et al., 1999; Hodgkinson et al., 2001; Ng et al., 2002). Also, the repercussions of GLUT1 gene overexpres- sion changes were described in cultured mesangial cells: cell hypertrophy, increased cell glucose mesangial uptake, extracellular matrix, collagen IV and fibronectin synthesis. All these alterations were reversed by rhein, which decreases GLUT1 (Zhu et al., 2001). Compared to control rats, diabetes determined reduction of medullar GLUT1 protein content, while denervation increased it in diabetic animals. Other authors already observed these changes determined by diabetes: compared to the cortical GLUT1 protein abundance, medullar GLUT1 levels are modified in a different way; they are reduced by diabetes (Asada et al., 1997; Dominguez et al., 1994). However, in diabetic rats, kidney denervation induced an increase in GLUT1 abundance toward normal levels, but the levels did not reach those observed in normal animals. These results suggest that, in order to maintain GLUT1 abundance and glucose metabolism, completely different mechanisms operate in renal tubular cells when compared to cortical cells. The different responses of the same glucose transporter, whether present in cortex or medulla, reflect its different functions, and these different patterns ratify that, in the present study, cortex and medulla were adequately dissected. The modulation of reduced medullar GLUT1 content by insulin administration described by Asada et al. in renal tubular cells suggests that GLUT1 protein abun- dance reduction occurs in response to the high glucose content presented to renal tubular cells (Asada et al., 1997). Urinary glucose was significantly higher in diabetic rats 1 month after diabetes induction as well as after 45 days of experimental diabetes, which includes 15 days of renal denervation. It was also increased in renal-denervated dia- B. D’Agord Schaan et al. / Autonomic Neuroscience: Basic and Clinical 104 (2003) 88–9492
  23. 23. betic as compared to diabetic animals. Diuresis showed the same trends, probably because of the osmotic effect of glucose on tubular fluid. These findings agree with those described in normal rats (Piryova et al., 1980) and could be explained by changes in GLUT2, the main glucose trans- porter found in proximal tubule S1 segment, described to be increased by diabetes as an adaptive response to maintain high transtubular glucose flux (Dominguez et al., 1994; Vestri et al., 2001). Renal denervation did not operate changes in albuminu- ria or urinary TGF-h1 in neither group. Since 15 days of denervation does not decrease urinary albumin or urinary TGF-h1 in experimental diabetes and does not increase levels of GLUT1 in renal cortex, acceleration of diabetic nephropathy cannot be assigned to it. Studying the same model, Matsuoka did not find any effect of denervation on albuminuria after 15 days, but he did find higher albumi- nuria in diabetic denervated rats 30 days after the surgical procedure (Matsuoka, 1993). Reinnervation is a definitive phenomenon that begins 14–21 days after surgical denervation (Kline and Mercer, 1980). In this reinnervation process, areas of denervation and hyperinnervation may develop, as it was recently described to occur in the heart of diabetic rats (Schmid et al., 1999). In this case, the result would be an increase in the sympathetic tonus, which could determine worsening of diabetic nephropathy. Of course, more extensive studies concerning the process of denervation and possible reinner- vation are necessary to fully explain what the effects of autonomic neuropathy on the kidney of diabetic rats are. Extending the period of denervation by another 15 days could not reflect the pattern of changes of denervation. Since hypertension is considered to have an important role in the pathogenesis of human diabetic nephropathy (Parving et al., 1981) and, in rats, diabetes and kidney denervation do not increase blood pressure levels (Schaan et al., 1997), we cannot rule out the possibility that this difference could account for the different end-points observed. Even though normal levels of blood pressure could be directly transmitted to the glomerulus in the denervated kidney, being a cause of injury, the fact that rats, unlike humans, do not walk in an upright position could also be protective. Taking all these observations together, the extent to which this model is really represent- ing what diabetic autonomic neuropathy determines in human kidneys is still unknown. We conclude that early-phase renal denervation in strep- tozotocin-diabetic rats produces a normalisation of previ- ously elevated cortical GLUT1 protein content, but urinary TGF-h1 and albumin are not significantly ameliorated. Since it has been hypothesised that renal denervation increases kidney damage, we speculate that this is likely to happen if animals’ blood pressure is increased (as in humans with diabetic nephropathy), but it does not occur in an animal model without increased mechanical stretch in its mesangial cells. References Asada, T., Ogawa, T., Iwai, M., Shimomura, K., Kobayashi, M., 1997. Recombinant insulin-like growth factor I normalizes expression of renal glucose transporters in diabetic rats. Am. J. Physiol. 42, F27–F37. Ayo, S.H., Radnik, R.A., Glass, W.F., Garoni, J.A., Rampt, E.R., Appling, D.R., Kreisberg, J.I., 1991. Increased extracellular matrix synthesis and mRNA in mesangial cells grown in high-glucose medium. Am. J. Physiol. 260, F185–F191. Bertoluci, M.C., Schmid, H., Lachat, J.J., Coimbra, T.M., 1996. Trans- forming growth factor-beta in the development of rat diabetic nephrop- athy. Nephron 74, 189–196. Block, N.E., Menick, D.R., Robinson, K.A., Buse, M.G., 1991. 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Granger, J.P., Novak, J., Schnackenberg, C., Williams, S., Reinhart, G.A., 1996. Role of renal nerves in mediating the hypertensive effects of nitric oxide synthesis inhibition. Hypertension 27, 613–618. Heilig, C.W., Concepcion, L.A., Riser, B.L., Freytag, S.O., Zhu, M., Cortes, P., 1995. Overexpression of glucose transporters in rat mesan- gial cells cultured in a normal glucose millieu mimics the diabetic phenotype. J. Clin. Invest. 96, 1802–1814. Henriksen, E.J., Rodnik, K.J., Mondon, C.E., James, D., Holloszy, J.O., 1991. Effect of denervation or unweighting on GLUT-4 protein in rat soleus muscle. J. Appl. Physiol. 70, 2322–2327. Hirakata, M., Kaname, S., Chung, U.G., Joki, N., Hori, Y., Noda, M., Takuwa, Y., Okazaki, T., Fujita, T., Katoh, T., Kurokawa, K., 1997. Tyrosine kinase dependent expression of TGF-beta induced by stretch in mesangial cells. Kidney Int. 51, 1028–1036. Hodgkinson, A.D., Millward, B.A., Demaine, A.G., 2001. Polymorphisms of the glucose transporter GLUT1 gene are associated with diabetic nephropathy. Kidney Int. 59, 985–989. Huang, W.-C., Fang, T.-C., Cheng, J.-T., 1998. Renal denervation prevents and reverses hyperinsulinemia-induced hypertension in rats. Hyperten- sion 32, 249–254. Kassab, S., Kato, T., Wilkins, C.F., Chen, R., Hall, J.E., Granger, J.P., 1995. Renal denervation attenuates the sodium retention and hypertension associated with obesity. Hypertension 25, 893–897. Kline, R.L., Mercer, P.F., 1980. Functional reinnervation and development of supersensitivity to NE after renal denervation in rats. Am. J. Physiol. 238, R353–R358. Knott, R.M., Robertson, M., Muckersie, E., Forrester, J.V., 1996. Regula- tion of glucose transporters (GLUT-1 and GLUT-3) in human retinal endothelial cells. Biochem. J. 318, 313–317. Lacchini, S., Fang, J., Fernandes, T.R.G., Irigoyen, M.C., 1997. Arterial pressure control in normal rats: role of renal nerves and sodium. J. Hypertens. 29 (3), 897. 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  24. 24. Matsuoka, H., 1993. Protective role of renal nerves in the development of diabetic nephropathy. Diabetes Res. 23, 19–29. Ng, D.P.K., Canani, L.H., Araki, S.I., Smiles, A., Warram, J.H., Krolewski, A.S., 2002. Polymorphisms in GLUT1 are associated with the develop- ment of diabetic nephropathy in diabetes mellitus. Diabetes 51 (Suppl. 2), A36. Oliveira, V.L.L., Irigoyen, M.C., Moreira, E.D., Strunz, C., Krieger, E.M., 1992. Renal denervation normalizes pressure and baroreceptor reflex in high renin hypertension in conscious rats. Hypertension 19, II-17–II-21. Parving, H.-H., Andersen, A.R., Smidt, U.M., Friisberg, B., Svendsen, P.A., 1981. Reduced albuminuria during early and aggressive antihy- pertensive treatment of insulin-dependent diabetic patients with diabetic nephropathy. Diabetes Care 4, 459–463. Piryova, B., Natcheff, N.B., Kirkova, N.L., 1980. Effect of renal denerva- tion on glucose transport. Acta Physiol. Pharmacol. Bulg. 6, 3–8. Schaan, B.D., Bertoluci, M., Lacchini, S., Machado, U., Irigoyen, M.C., Schmid, H., 2001. Increased renal GLUT1 abundance, albuminuria and urinary TGF-h1 in STZ-induced diabetic rats: implications for the de- velopment of diabetic nephropathy (DN). Horm. Metab. Res. 33, 1–6. Schaan, B.D., Maeda, C.Y., Timm, H., Medeiros, S., Moraes, R., Ferlin, E., Fernandes, T.G., Ribeiro, J.P., Schmid, H., Irigoyen, M.C., 1997. Time course of changes in heart rate and blood pressure variability in strep- tozotocin-induced diabetic rats treated with insulin. Br. J. Med. Biol. Res. 30, 1081–1086. Schmid, H., Bertoluci, M.C., Coimbra, T.M., 1989. Determinacßa˜o da ex- crecßa˜o urina´ria de albumina por eletroimunoensaio (EIE). Arq. Bras. Endocrinol. Metabol. 33, 73–75. Schmid, H., Forman, L.A., Cao, X., Sherman, P.S., Stevens, M., 1999. Heterogeneous cardiac sympathetic denervation and decreased myocar- dial nerve growth factor in streptozotocin-induced diabetic rats: impli- cations for cardiac sympathetic dysinnervation complicating diabetes. Diabetes 48, 603–608. Schmidt, R.E., Sharp, D.W., 1982. Axonal dystrophy in experimental dia- betic autonomic neuropathy. Diabetes 31, 761–770. Sundkvist, G., Lilja, B., 1993. Autonomic neuropathy predicts deterioration in glomerular filtration rate in patients with IDDM. Diabetes Care 16 (5), 773–779. Vestri, S., Okamoto, M.M., de Freitas, H.S., Aparecida dos Santos, R., Nunes, M.T., Morimatsu, M., Heimann, J.C., Machado, U.F., 2001. Changes in sodium or glucose filtrated rate modulate expression of glucose transporters in renal proximal tubular cells of rat. J. Membr. Biol. 182 (2), 105–112. Wakisaka, M., Spiro, M.J., Spiro, R.G., 1994. Synthesis of type VI colla- gen by cultured glomerular cells and comparison of its regulation by glucose and other factors with that of type IV collagen. Diabetes 43, 95–103. Wakisaka, M., He, Q., Spiro, M.J., Spiro, R.G., 1995. Glucose entry into rat mesangial cells is mediated by both Na+ -coupled and facilitative trans- porters. Diabetologia 38, 291–297. Zhu, J., Liu, Z., Li, Y., 2001. Inhibition of glucose transporter 1 over- expression in mesangial cells by rhein. Zhonghua Nei Ke Za Zhi 40, 537–542. B. D’Agord Schaan et al. / Autonomic Neuroscience: Basic and Clinical 104 (2003) 88–9494
  25. 25. Case Reports Right Ventricular Bronchogenic Cyst We report an exceedingly rare case of primary bronchogenic cyst in the outflow tract of the right ventricle in a 48-year-old woman. In our review of the world literature, we found only 1 other report of an intracardiac bronchogenic cyst. Our patient’s only symp- tom was mild dyspnea not associated with physical exertion, and the cyst was resect- ed successfully. We report clinical aspects of the case, diagnostic methods, surgical management, and histopathologic findings. (Tex Heart Inst J 2003;30:71-3) he resection of a cardiac tumor was first performed in 1951, when Maurer1 successfully removed an epicardial lipoma. In 1954, extracorporeal circula- tion enabled Crafoord2 to excise successfully a left atrial myxoma. Primary cardiac neoplasms are 100 to 1,000 times less prevalent than are sec- ondary neoplasms of the heart.3,4 Autopsy findings have shown that their preva- lence in the general population ranges from 0.0017% to 0.28%.5 About 75% of primary cardiac neoplasms are benign.5 Of these benign tumors, about 50% are myxomas. In children, rhabdomyomas are the most common.4,6,7 Most malignant tumors are sarcomas, but lymphomas, thymomas, and plasma- cytomas have also been reported. Bronchogenic cysts have benign characteristics and comprise 1.3% of all prima- ry tumors of the heart and pericardium.8 In our review of the world literature, we found only 1 case of an intracardiac bronchogenic cyst, which occurred in the left atrium of a 43-year-old woman and involved the entire atrial septum.8 Case Report In October 1996, a previously healthy 48-year-old woman was seen in our hospi- tal. She complained of dyspnea not related to physical exertion. She reported no history of family cardiopathy, hypertension, smoking, alcoholism, or hormonal disorders. At physical examination, her vital signs were blood pressure, 120/80 mmHg; heart rate, 72 beats/min; and axillary temperature, 36.5 °C. Pulmonary ausculta- tory findings consisted of bilateral vesicular breath sounds without rales. Cardiac auscultatory findings included a regular rhythm, S1 and S2 audible, and a low-fre- quency, harsh systolic ejection murmur, most intense in the 4th left intercostal space and radiating to the 2nd left intercostal space, without thrills. She presented no jugular distention, adenopathy, hepatomegaly, ascites, or edema in the lower limbs. The rest of the physical examination was normal. An electrocardiogram revealed sinus rhythm and right bundle branch block. The chest radiograph was normal. Transthoracic echocardiography revealed a cyst with well-defined margins, which caused a 4.2-cm reduction in the right ventricular (RV) cavity and subtotal obstruction of the RV outflow tract. The RV cavity was enlarged, but the size of the other cardiac cavities was normal. The valves were morphologically and func- tionally normal. The pericardium exhibited normal, free movement of its layers. Magnetic resonance imaging showed a cystic mass (Fig. 1) invading the myo- cardium of the anterior wall of the right ventricular outflow tract. This mass meas- ured 3.3 × 4.2 cm in diameter, and obstructed the RV outflow tract almost com- pletely. Right ventriculography revealed a spherical mass in the outflow tract, which produced a systolic gradient of 46 mmHg. Coronary angiography findings were normal. Paulo R. Prates, MD Lucas Lovato, MD Abud Homsi-Neto, MD Marinez Barra, MD João R.M. Sant´Anna, MD, PhD Renato A.K. Kalil, MD, PhD Ivo A. Nesralla, MD, PhD Key words: Bronchogenic cyst/surgery; case report; female; heart neoplasms/ diagnosis; heart neoplasms/ primary; heart ventricle From: Surgery Service, Instituto de Cardiologia do Rio Grande do Sul, Fundação Universitária de Cardiologia, Porto Alegre, RS 90.620-001, Brazil Address for reprints: Dr. Paulo R. Prates, Unidade de Pesquisa do IC/FUC, Av. Princesa Isabel 395, Santana, Porto Alegre, RS 90.620-001, Brazil E-mail: prprates@cardiol.br © 2003 by the Texas Heart ® Institute, Houston Texas Heart Institute Journal Right Ventricular Bronchogenic Cyst 71 T
  26. 26. Referred to surgery with a diagnosis of RV cystic tumor, the patient underwent median sternotomy, pericardiotomy, cannulation of the ascending aorta and of the superior and inferior venae cavae, extracor- poreal circulation at a flow rate of 4 L/min, infusion of a hypothermic crystalloid cardioplegic solution, and hypothermia at 30 °C. The protrusion caused by the tumor in the RV out- flow tract was seen. We performed a right ventricu- lotomy, exposed the cystic mass (Fig. 2), and resected it completely. We patched the endocardium with a small piece of preserved bovine pericardium. The aortic clamping time was 25 minutes, and cardiopul- monary bypass time was 42 minutes. The surgery was successful. The patient had an uneventful post- operative recovery and was completely asymptomatic at her discharge on the 7th postoperative day. Histo- logic examination revealed that the mass was a bron- chogenic cyst (Figs. 3 and 4). Volume 30, Number 1, 200372 Right Ventricular Bronchogenic Cyst Fig. 1 A) Sagittal magnetic resonance image shows a high- intensity lesion (arrow) causing obstruction of the right ven- tricular outflow tract. B) Axial magnetic resonance image shows high-intensity lesion (arrow) invading the myocardium of the anterior wall of the right ventricular outflow tract. Fig. 2 Operative exposure of the cystic mass. Fig. 3 Photomicrograph of the cystic wall, low magnification (H&E, orig. ×200). Fig. 4 Cystic wall, high magnification (H&E, orig. ×400). Pho- tomicrograph shows respiratory epithelium and intramural cartilage, indicated by the arrow. A B

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