Approach to Cyanoticcongenital heart disease Dr Varsha Atul Shah
Incidence of CHD The incidence of moderate to severe structural congenital heart disease in live born infants is 6 to 8 per 1,000 live births. Data from the New England Regional Infant Cardiac Program suggest that approximately 3 per 1,000 live births have heart disease that results in death or requires cardiac catheterization or surgery during the first year of life.
Top Five Diagnoses Presenting at Different Ages(%) Age on admission: 0-6 d D-Transposition of great arteries 19 Hypoplastic left ventricle 14 Tetralogy of Fallot 8 Coarctation of aorta 7 Ventricular-septal defect 3 Others 49 Age on admission: 7-13 d Coarctation of aorta 16 Ventricular septal defect 14 Hypoplastic left ventricle 8 D-Transposition of great arteries 7 Tetralogy of Fallot 7 Others 48 Age on admission: 14-28 d Ventricular septal defect 16 Coarctation of aorta 12 Tetralogy of Fallot 7 D-Transposition of great arteries 7 Patent ductus arteriosus 5 Others 53
MAJOR CCHD CATEGORIES AND THEIR OCCURRENCE IN SINGAPORE
CYANOSIS – DEFINITION AND DIAGNOSTICDIFFICULTIES PRESENCE OF > 3g/dl of Deoxy Hb which correlates with 80-85% Spo2. Can be missed when mild, in dark races and anemia due to decreased deoxy Hb Can be misdiagnosed as CCHD in acrocyanosis, non cardiac causes of cyanosis like pulmonary causes, CNS causes and Cyanosis with normal Po2.
Differential Diagnosis of Cyanosis in the Neonate Primary cardiac lesions Decreased pulmonary blood flow, intracardiac right-to-left shunt Critical pulmonary stenosis Tricuspid atresia Pulmonary atresia/intact ventricular septum Tetralogy of Fallot Ebstein anomaly Total anomalous pulmonary venous connection with obstruction Normal or increased pulmonary blood flow, intracardiac mixing Hypoplastic left heart syndrome Transposition of the great arteries Truncus arteriosus Complete common atrioventricular canal Total anomalous pulmonary venous connection without obstruction Other single-ventricle complexes
Pulmonary lesions (intrapulmonary right-to-left shunt) Primary parenchymal lung disease Aspiration syndromes (e.g., meconium and blood) Respiratory distress syndrome Pneumonia Airway obstruction Choanal stenosis or atresia Pierre Robin syndrome Tracheal stenosis Pulmonary sling Absent pulmonary valve syndrome Extrinsic compression of the lungs Pneumothorax Pulmonary interstitial or lobar emphysema Chylothorax or other pleural effusions Congenital diaphragmatic hernia Thoracic dystrophies or dysplasia
Other causes Hypoventilation Central nervous system lesions Neuromuscular diseases Sedation Sepsis Pulmonary arteriovenous malformations Persistent pulmonary hypertension Cyanosis with normal PO2 Methemoglobinemia Polycythemia
Hyperoxia Test Most sensitive and specific tool for evaluation of a neonate with suspected CHD especially in the absence of ECHO. Helps to differentiate the cardiac and non cardiac causes of cyanosis PGE1 can be initiated based on the findings of this test. Initial measurement in room air then after 10 min of 100% o2 arterial or TCOM Po2 is measured.
Hyperoxia test contd… Pulse oximetry not reliable Both pre and post ductal sites used Differential cyanosis can aid in diagnosis >250mmhg- no structural cyanotic HD < 100 mmHg – intracardiac shunting- CCHD 100-250 mmHg- intracardiac mixing lesions < 100 mmHg most likely duct dependent lesion so PGE1 can be started until anatomic lesion defined
History and physical examination Onset of cyanosis Hypoxic spells, exercise intolerance, squatting, frequent chest infections, CHF, Failure to thrive Cyanosis, clubbing, pulse, Four limb BP, growth, dysmorphology Cardiovisceral situs Palpation and auscultation
Salient clinical findings of conditions withdecreased PBF TOF: Cyanosis proportional to RVOT obstruction Cyanotic spells and its management RV apex, parasternal heave , Single S2, Ejection systolic murmur at Left upper sternal edge TOF with PA: Single S2 but soft murmur sometimes continuous from the MAPCAS. Occasionally CCF
Tricuspid atresia: cyanosis, LV impulse, S2 single, Holosystolic murmur along left sternal edge TGA with VSD and PS or DORV with PS- TOF picture Ebstein’s- depends on degree of displacement of Tricuspid Valve, can be mild till teenage or severe with cyanosis in neonate. WPW syndrome is an association, multiple clicks, holo systolic TR murmur, gallop.
Salient clinical findings of conditions withIncreased PBF D-TGA with IVS- CYANOSIS and tachypnea, S2 single and loud, soft or absent MURMUR. D-TGA with VSD- presents with cardiac failure, subtle cyanosis and holo systolic VSD murmur. L-TGA- physiologically corrected so can be asymptomatic but may have associated lesions like VSD, EBSTEIN’S, PS, WPW syndrome etc.
DORV without PS is like VSD DORV WITHOUT PS DORV+TGA, TAUSSIG DORV+ TGA- Sub arterial BING TYPE VSD, Cardiac Failure, Loud ESM, left sided obstructive lesions are common
Salient clinical findings of conditions with increased PBF TAPVR- L-R shunt with Cardiac failure features, varia ble cyanosis depending on the obstruction, m ay need emergency surgery, no response to PGE1.
Truncus arteriosus- in neonates murmur and mild cyanosis, later develops Cardiac failure, valve insufficiency, si ngle S2, Loud ESM with thrill and MDM due to mitral flow murmur
Single ventricle- with PS- TOF like, without PS-TGA with VSD like SINGLE VENTRICLE HLHS Hypoplastic left heart syndrome-cyanosis and poor perfusion and cardiac failure with non descript murmur.
Medical Management PGE1: drug used to maintain patency of ductus arteriosus in duct dependent conditions for systemic and pulmonary blood flow 0.01-0.4 mic./kg/min titrated according to response. Lower doses effective and central line is preferred not mandatory. Dilute with NS OR 5%D Apnea, hypotension, pyrexia, flushing, diarrhea, edema, gastric outlet obstruction, inhibition of platelet aggregation on long term use.
Antifailure medications used to treat heartfailure in mixing lesions.Frusemide , spironolactone, digoxin, andcaptopril can be used. Prognosis after SurgeryTetralogy of Fallot: Surgical risk<5 percent andperformed as early as 3 months of age usuallybetween 4-6 months, post op need to look forRV failure, PR, Conduction blocks, residualVSD.TOF WITH PA: BT shunt or direct completerepair: RV-PA conduit +VSD CLOSUREFor MAPCAs - unifocalisation
Prognosis contd… Tricuspid atresia- 5 year survival 80% and 10 year survival 70% post op. HLHS:25% MORTALITY stage 1, 5% for Stage 2, 15-20% for Stage 3. Overall survival after stage 3 55% at 4 years. Ebstein’s : 5-20% mortality in valve repair and ASD closure Truncus Arteriosus: 10-30% surgical mortality DORV: Rastelli: 5-15% mortality
References Nelson’s TB of Pediatrics 18th edn. Cloherty manual of neonatal care, 6th edn, Park, Paediatric cardiology for practitioners, 5th edn Nada’s text book of Paediatric cardiology, 2nd edn A practical approach to Cyanotic congenital heart disease, Yip WCL, Tay JSH: Singapore medical journal, 1983