11 year old boy with heart disease detected at 2 days of age with cyanosis and exertional dyspnoea noted after one year of age; no cyanotic spells
Possibilities:
Cyanotic congenital heart disease with decreased pulmonary blood flow – Fallot like physiology
Admixture lesions like single atrium and total anomalous pulmonary venous connection (TAPVC)
Anomalous systemic venous connection to left atrium
Pulmonary arteriovenous fistula
Ebstein’s anomaly
Development of Eisenmenger physiology in left to right shunts – less likely to be detected on day 2
Transposition of great arteries with good pulmonary blood flow, presenting with Eisenmenger syndrome later
Severe pulmonary stenosis (PS) with atrial septal defect and right to left shunt
Tetralogy of Fallot with flap valve ventricular septal defect (VSD)
Flap attached to VSD which will restrict the flow across the VSD and can cause supra systemic right ventricular pressure.
How is DORV, VSD, PS different from Tetralogy of Fallot in clinical findings?
A prominent systolic murumur co-existing with severe cyanosis is in favour of double outlet right ventricle (DORV) than Tetralogy of Fallot. Prominent left parasternal heave is also more likely in DORV.
Definition of continuous murmur
Continuous murmur is a murmur which starts in systole and continues uninterruptedly through the second heart sound into part or whole of diastole. Highest intensity of continuous murmur is usually heard in rupture of sinus of Valsalva (RSOV) into the right ventricular outflow tract (RVOT).
What will happen to cardiac murmurs when hematocrit increases?
Intensity of cardiac murmur decreases as the hematocrit increases, due to an increase in viscosity.
Reynold’s number: Re = (V x d x rho) / eta
V = velocity of blood stream; d = diameter of the vessel; rho = density of fluid; eta = viscosity of blood
When Reynold’s number is above 2000, flow becomes turbulent. When viscosity (eta) increases, Reynold’s number decreases.
Catch 22 syndrome – 22q11 deletion
22 q deletion is likely if there are dysmorphic features and arterial anomalies in Tetralogy of Fallot like right aortic arch and pulmonary artery branch stenosis. It is associated with mental retardation, which may be mild.