Sports cardiology


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Sports cardiology

  1. 1. 16.1 IntroductionElectrophysiological studies are instrumentalmethods enabling the registration of electric endo-cavitary cardiac signals relative to the variousphases of the cardiac cycle. Registration is carriedout through unipolar or bipolar electrocatheters,which also allow electrical stimulation of the heart.Stimulation of the cardiac chambers is an ex-tremely useful method for accurately measuringintervals and/or pauses and for reproducing in thelaboratory arrhythmias that patients may experi-ence clinically (arrhythmic inducibility test). Elec-trophysiological evaluations can be performed viathe transesophageal or endocavitary pathways.Allthe material used both for endocavitary and trans-esophageal electrophysiological studies is sterileand for single use.A transesophageal electrophysiological studyis conducted by inserting an electrocatheterthrough the nasal cavity and into the esophagus.The posterior wall of the left atrium is in strictproximity with the esophagus and therefore withthe electrocatheter it is possible to register thesignals emanating from the left atrium, as well asperforming programmed atrial stimulations. Thetheoretical advantages of this method are reducedinvasiveness compared to an endocavitary studyand the possibility of registrations and/or stipula-tions even during physical exertion (bed-ergome-ter) [1]. Limits include the scarcity of electrical in-formation (registration only of atrial signals) com-pared to a complete endocavitary study, the possi-bility of stimulating only the atrial cavity and notthe ventricular cavity, potentially low patient tol-erability (painful stimulations), the need to con-sider an eventual ablative intervention in anothercontext, which, in case of an endocavitary study,can be carried out at the same time.An endocavitary electrophysiological study isconducted by inserting electrocatheters (gener-ally between one and four) directly into the cardiaccavities. The procedure is carried out with localanesthesia and the catheters are inserted throughvenous and/or, more rarely, arterial vascular accesspoints. The insertion of the catheters into the vas-cular system towards the heart and, subsequently,their positioning in the various anatomical seg-ments of the heart, is not painful and is performedunder a fluoroscopic guide (Fig. 16.1). The elec-trocatheters (see also Chapter 17) are positioned incertain anatomically determined areas of the heart(for example the lateral wall of the right atrium,bundle of His, coronary sinus, right ventricleapex). The registration of electric signals in theseareas enables the accurate reconstruction of the se-quence of endocavitary activation of a particularcardiac rhythm. A precise endocavitary electro-gram of the heartbeat is therefore reconstructed al-lowing accurate diagnosis of the electrophysiolog-ical genesis of cardiac arrhythmias. Through theelectrocatheters, as previously mentioned, pro-grammed stimulations of the cardiac cavities canbe carried out. These enable further measurementsof intervals and/or pauses, artificial initiation ofcardiac arrhythmias (Fig. 16.2) leading to possibleclinical arrhythmic episodes in a patient.Electrophysiological Studies in AthletesLuigi Sciarra, Antonella Sette, Annamaria Martino,Alessandro Fagagnini, Lucia de Luca, Ermenegildo de Ruvo,Claudia Tota, Marco Rebecchi, Fabio Sperandii,Emanuele Guerra, Gennaro Alfano, Fabrizio Guarracini,Fabio Pigozzi and Leonardo Calò16185M. Fioranelli and G. Frajese (eds.), Sports Cardiology,DOI: 10.1007/978-88-470-2775-6_16, © Springer-Verlag Italia 2012CARDIAC ARRHYTHMIASL. Calò ( )Electrophysiology DepartmentPoliclinico Casilino, Rome, Italy
  2. 2. 16.2 Clinical Evaluationof Arrhythmia in Patients:General PrinciplesSporadic arrhythmias of benign prognostic signif-icance can be present even in perfectly normalsubjects. The athlete can also manifest rhythm dis-orders connected to the intensified vagal tonecaused by physical exercise or by adrenergic hyper-tone during intense physical activity. Establishinga limit between normality and disease is not alwayssimple. For this reason the clinical evaluation of ar-rhythmia in an athlete needs to be accurate andtakes advantage of opportune instrumental diag-nostic principals, from the most simple to the mostcomplex, which may become necessary.As specified in the COCIS protocol (Organiza-tional Cardiac Committee for Suitability to Prac-tice Sport) in 2009 [2], the connection of suitabil-ity for competitive sport activity has to include:• suspected or demonstrated arrhythmias;• heart diseases that are predisposing factors formalign arrhythmias;• arrhythmias treated with transcatheter ablation,pacemaker implantation or defibrillators.The clinical evaluation of arrhythmia in an ath-lete has to be based on three levels for an adequateidentification of competitive suitability. Accurategathering of the patient’s medical history, an ob-jective examination, and a 12-lead electrocardio-gram at rest and after a step test are the first levelof evaluation during a medical examination to es-tablish competitive suitability. The second level ofevaluation must also include non-invasive assess-ments, such as mono- and bi-dimensional echocar-diography studies and color-Doppler analysis, amaximum ergometric test, and the 24-hour Holtermonitor. The latter must include a workout sessionduring registration, in the absence of any con-traindications, and a nycthemeral cycle. If neces-L. Sciarra et al.186terQuadripolar catheon the His bundleerDecapolar cathetenusin the coronary sinterQuadripolar cathecularfor the interventricseptumeterTwentypolar catheon the tricuspidalannulusFig. 16.1 Example offluoroscopic visualizationof electrocatheterspositioned in the heartduring anelectrophysiologicalendocavitary study (lateralanterior oblique view)Fig. 16.2 Example of ventricular tachycardia induction us-ing programmed ventricular stimulation. The pacingcatheter is positioned in the right ventricular apex and therecorded signal is identified by RV. From this site, pro-grammed ventricular stimulation has been performed, con-sisting of the paced train of extrastimulus (S1) and two pre-mature beats (S2 and S3) that induced the rapid monomor-phic ventricular tachycardia with initial hemodynamic com-promise. It has been promptly interrupted by using ventric-ular stimulation in overdrive, i.e. the frequency of ventricu-lar pacing is higher than the frequency of tachycardia
  3. 3. sary during this level, biohumoral examinationscan be included (hemochromocytometric tests,thyroid hormone tests, and possibly infectiologytests and other indicated tests).Based on the type of arrhythmia documentedand on the symptoms reported by the athlete, itcould be necessary to pass to a third level of eval-uation that includes invasive and non-invasivestudies. Third-level tests are: the tilt test, pharma-cological tests (atropine, isoproterenol, flecainideetc.), the investigation of ventricular late potentialswith the signal averaging method, the variabilityof cardiac frequency study, the alternance of T-wave study, the transesophageal electrophysiologystudy at rest and under stress, and the endocavitaryelectrophysiology study.16.3 Indications forElectrophysiological Studiesin AthletesAn electrophysiology study is part of the thirdlevel of the evaluation of an athlete. It may be in-dicated based on the symptoms reported by thesubject and the arrhythmias found during the sec-ond-level tests, in particular surface ECG, HolterECG and the maximum stress test. The symp-toms most often reported by athletes include pal-pitation at rest and under stress, and occasionallypre-syncopal and/or syncopal episodes. All symp-toms, however, need a high degree of attention anddiagnostic accuracy.As for the selection criteria for an electrophysi-ological endocavitary study, the usual indications forthis exam must be valid both for athletes and seden-tary subjects. However, in athletes, other indica-tions for an electrophysiological endocavitary studyare more closely related to arrhythmic risk tests inconnection with sport, e.g. with Wolff-Parkinson-White (WPW) syndrome. Furthermore, it includesnot only the diagnostic results but also the possibletherapeutic results. In other words, invasive electro-physiological studies are certainly indicated in ath-letes when there is also an indication for ablativetreatment of a certain arrhythmia (see Chapter 17).Based on a subject’s symptoms it is possible topropose an invasive electrophysiological evalua-tion in the presence of: recurrent syncopal episodesassociated with palpitations [3] (suspected pres-ence of tachyarrhythmias); syncopal episodes inpresence of heart disease that is not the cause ofnon-suitability or familiarity with sudden death,following second-level assessments; paroxysmalpalpitations and/or hemodynamic compromise; pal-pitations with a strong suspicion of supraventricu-lar tachycardia; palpitation in subjects with heartdisease or suspected ventricular tachycardia.On the other hand, an electrophysiological studycan be indicated even if specific arrhythmias or ar-rhythmogenic conditions are found during the first-and/or second-level assessments. Obviously, evenin this situation, a possible indication for a more in-depth invasive electrophysiological study cannotinvolve clinical elements and the patient’s medicalhistory, which provide a clinical classification ofthe arrhythmic problem in the subject, ruling out orconfirming, for example, the presence of a poten-tial underlying structural cardiopathy.As for bradyarrhythmias, an electrophysiolog-ical study can be taken into consideration with theobjective of studying supra-Hisian, infra-Hisianand sub-Hisian atrioventricular conduction, onlyin the presence of any type of atrioventricularblock, only if these are associated with delays inintra-ventricular conduction, and in the rare casesin which second-degree atrioventricular blockwith narrow QRS is found during physical exer-tion [4,5].In patients with supraventricular tachycardia,electrophysiological studies can be indicated in thecase of: paroxysmal forms in which re-entranttachycardia is suspected (nodal tachycardia, atri-oventricular re-entrant tachycardia); paroxysticsupraventricular tachycardia in the absence ofWPW syndrome during surface ECG to investi-gate whether arrhythmias induced during the elec-trophysiological study do not have a high fre-quency; iterative and persistent supraventriculartachycardia (for example inappropriate sinusaltachycardia, re-entrant tachycardia through a slowdecremental accessory pathway, Coumel tachy-cardia and focal atrial tachycardia resulting fromincreased automaticity); identification of possi-ble triggers the paroxystic atrial fibrillation, suchas nodal re-entrant tachycardia or an accessory16 Electrophysiological Studies in Athletes 187
  4. 4. pathway, pulmonary venous foci with the relatedpossibility of ablation; asymptomatic subjects af-fected by WPW syndrome and in absence of un-derlying heart disease (with the exception of chil-dren under 12 years of age since, according to theCOCIS, the stratification of risk can be envisagedbeyond this age).A separate and in-depth consideration needs bereserved for the value of the electrophysiologicalstudy in ventricular pre-excitation syndrome, andmore precisely in WPW syndrome. Physical activ-ity, as is known, promotes the trigger of certaincardiac arrhythmias, and this is true even in ven-tricular preexcitation. In WPW syndrome a theo-retical risk of sudden death exists, albeit very low.This risk is directly connected to the presence ofatrial fibrillation (generally, even if not exclu-sively, triggered by atrioventricular re-entranttachycardia) and by an accessory pathway with anelevated anterograde conductive capacity from theatria to the ventricles. The arrhythmic risk is notdeducible by non-invasive clinical and structuralparameters and can occur even in a completelyasymptomatic subject. All risk parameters con-nected to the syndrome are, however, easily iden-tifiable in the course of the electrophysiologicalstudy. Therefore, this study is generally indicatedin competitive subjects with ventricular preexcita-tion and can be carried out via both the trans-esophageal and endocavitary pathways (seeabove). According to the judgment of experts atthe COCIS, the invasive electrophysiological eval-uation can be delayed in asymptomatic subjectsbelow 12 years of age, due to the almost virtualrisk of atrial fibrillation and sudden death. On thebasis of the parameters of the electrophysiologicalstudy, suitability to perform competitive activi-ties can be conceded in asymptomatic subjectsand those without heart disease: atrial preexcita-tion fibrillation inducibility with a minimum R-Rinterval > 240 ms (baseline conditions) and > 200ms (under stress); non inducibility of atrial fibril-lation and/or atrioventricular re-entrant tachycar-dia at rest and under stress, and an anterograde ef-fective refractory period of the accessory pathway> 240 ms at rest and > 200 ms under stress [6,7].Ventricular tachycardias in the presence of as-serted organic heart disease are not covered by thepresent study, as they occur in subjects for whom theproblem of competitive suitability cannot be takeninto consideration. Nonetheless, electrophysiologi-cal endocavitary studies can be useful in certainforms of ventricular tachycardia which are suppos-edly benign, namely in subjects without significantstructural heart disease. These arrhythmic formsmainly include: fascicular ventricular tachycardia,ectopic idiopathic ventricular tachycardia originat-ing from the right and, more rarely, left ventricularoutflow tract. Even for these arrhythmias the ideathat an electrophysiological study is still indicatedwhen an ablative indication also subsists is valid.Furthermore, in certain cases, it may be difficult toconduct a differential diagnosis based on first- andsecond-level studies, between ventricular tachycar-dia of the right ventricular outflow tract and ventric-ular tachycardia of the right ventricular outflow tractin the context of arrhythmogenic myocardiopathy ofthe right ventricle. Electrophysiological endocavi-tary studies can provide useful data for the differen-tial diagnosis. In fact, in arrhythmic cardiopathy,ventricular stimulation easily tends to induce sus-tained ventricular tachycardia based on the re-entrymechanism (presence of the phenomenon of con-cealed entrainment). Instead, in idiopathic ventric-ular tachycardias, often only the stimulation after in-fusion of isoproterenol is capable of reproducingsuch arrhythmias (catecholamine-mediated tachy-cardia resulting from an intensified automatism).Ventricular fascicular tachycardia, in some cases,can be confused with paroxystic supraventriculartachycardias conducted with aberration. In thesecases, electrophysiological study results are ex-tremely useful for clear differential diagnosis [8-10].16.4 Possible New Areasof ApplicationElectrophysiological endocavitary studies can becarried out with specific catheters that allow three-dimensional mapping of the cardiac chambers,providing both electric and anatomic (elec-troanatomic maps) information. This is made pos-sible by increasingly accurate mapping systemsand three-dimensional non-fluoroscopic naviga-tion. These systems enable the localization of theL. Sciarra et al.188
  5. 5. letes with malignant ventricular arrhythmias, help-ing to identify or rule out the presence of potentialunderlying structural heart disease.References1. Vergara G, Furlanello F, Disertori M et al (1988) Induc-tion of supraventricular tachyarrhythmia at rest and du-ring exercise with transesophageal atrial pacing in theelectrophysiological evaluation of asymptomatic ath-letes with Wolff-Parkinson-White syndrome. Eur HeartJ 9:1119-11252. Comitato Organizzativo Cardiologico per l’Idoneitàallo Sport ANCE-ANMCO-FMSI-SIC-SIC SPORT(2009) Protocolli cardiologici per il giudizio di idoneitàallo sport agonistico 2009. Cesi Casa Editrice Scienti-fica Internazionale, Roma3. Lawless CE, Briner W et al (2008) Palpitations in ath-letes. Sports Med 38:687-7024. Zeppilli P, Fenici R, Sassara M et al (1980) Wencke-bach second-degree A-V block in top-ranking athletes:an old problem revisited. Am Heart J 100:281-2945. Alboni P, Pirani R, Paparella N et al (1985) Elec-trophysiology of normal anterograde atrio-ventricularconduction with and without autonomic blockade. EurHeart J 6:602-6986. Delise P, Sciarra L. et al (2007) Asymptomatic Wolff-Parkinson-White: what to do. Extensive ablation ornot? J Cardiovasc Med 8:6687. Brembilla-Perrot B, Ghawi R et al (1993) Electrophy-siological characteristics of asymptomatic Wolff-Par-kinson-White syndrome. Eur Heart J 14:511-5158. Heidbüchel H, Hoogsteen J, Fagard R et al (2003)High prevalence of right ventricular involvement in en-durance athletes with ventricular arrhythmias. Role ofan electrophysiologic study in risk stratification. EurHeart J 24:1473-14809. Biffi A, Ansalone G, Verdile L et al (1996) Ventriculararrhythmias and athletes heart Role of signal-averagedelectrocardiography. Eur Heart J 17:557-56310. Furlanello F, Bettini R, BertoldiA et al (1989)Arrhyth-mia patterns in athletes with arrhythmogenic right ven-tricular dysplasia. Eur Heart J 10 Suppl D:16-1911. L. Sciarra, E. Marras, E. De Ruvo et al (2008) Rightventricular voltage mapping. In Brugada Syndrome: al-ways an electrical disease in structurally normal hearts?Heart Rhythm:S7412. Corrado D, Basso C, Leoni L et al (2005) Three-di-mensional electroanatomic voltage mapping increa-ses accuracy of diagnosing arrhythmogenic right ven-tricular cardiomyopathy/displasia. Circulation111:3042-305013. Corrado D, Basso C, Leoni L et al (2008) Three-di-mensional electroanatomical voltage mapping and hi-stologic evaluation of myocardial substrate in rightventricular outflow tract tachycardia. J Am Coll Car-diol 51:731-73916 Electrophysiological Studies in Athletes 189Fig. 16.3 Example of the bipolar voltage map of the rightventricle reconstructed by the three-dimensional elec-troanatomical mapping system (CARTO®, BiosenseWebster). The anteroposterior view shows a wide low-voltage area (red regions) in the right ventricular free wall,a peritricuspid area and basal region of the right ventricu-lar outflow tract. Scar areas (red) are surrounded by low-voltage areas (yellow-blue). Purple areas identify normalmyocardial tissue. The patient is an athlete with a Brugadatype ECG pattern. As is well known, Brugada is a syn-drome that affects patients with a structurally normal heart.The electroanatomical mapping has shown structural ab-normalities of the right ventricle. The subject is obviouslynot suitable for practicing sportelectrocatheters through the emission of mag-netic fields and/or the use of electric impedance.Maps of this kind are certainly more useful forsupporting ablative interventions of complex ar-rhythmias. Furthermore, some of these three-di-mensional maps can also enable adequate meas-urement of the voltage of endocavitary signalsregistered by the electrocatheter [11,12]. It is in-tuitive to see how, in case of an eventual scararea on the ventricular muscle, or an area substi-tuted by fibrous or fibroadipose tissue, the catheterpositioned in these regions can register very lowsignals or signals that are completely absent (Fig.16.3). This type of reconstruction has proven to bevery useful, for example, as published by the Ital-ian group of Corrado, in the diagnosis of the ar-rrhythmogenic cardiopathy of the right ventricle[13]. It is also possible to predict that this methodcould be used even in the diagnostic course of ath-