Congenital Heart Defects Functional Overview Dr. Yasser Salem

Objectives Obstructive lesions right or left Mixing lesions Shunt lesions left to right or right to left Univentricular physiology Miscellaneous Anomalies of coronary arteries Vascular ring

Obstructive cardiac lesions Acyanotic Cyanotic

Obstructive cardiac lesions low OXYGEN Enough blood, just not enough oxygen in the blood COMPLEX CARDIAC LESIONS = MIXING LESIONS low BLOOD Enough oxygen, just not enough blood flow OBSTRUCTIVE CARDIAC LESIONS COMBINATION

Left sided obstructive lesions

Left sided obstructive lesions Increased flow Backward effects Pulmonary venous congestion Increase RV afterload RV hypertrophy and failure Systemic venous congestion Forward effects Decrease peripheral tissue perfusion Decrease coronary perfusion Myocardial ischemia

Left sided obstructive lesion Aortic stenosis Subvalvular (SAM, Pompe) Valvular congenital stenosis Supravalvular (Aortic coarc., hypoplastic arch) Mitral stenosis Subvalvular (Shone’s) Supravalvular (core triatriatum)

Shone’s anomaly

Core triatriatum

Left sided obstructive lesion Hypoplastic left heart syndrome (HLHS) Tricuspid atresia with transposed great arteries Double-inlet left ventricle IAA DORV (some variations)

Right sided obstructive lesions

Right sided obstructive lesions Backward effects Pulmonary venous congestion Increase RV afterload RV hypertrophy and failure Systemic venous congestion Forward effects Decrease peripheral tissue perfusion Decrease coronary perfusion Myocardial ischemia Decrease pulmonary perfusion (lung oligemia) CYANOSIS

Right sided obstructive lesions Tricuspid atresia Pulmonary atresia with IVS TOF with pulmonary atresia Severe Ebstein’s anomaly of the tricuspid valve Critical PS DORV (some variations)

sided obstructive lesion Right Left Pulmonary stenosis Aortic stenosis Subvalvular (SAM, Pompe) Valvular congenital stenosis Supravalvular (Aortic coarc., hypoplastic arch) Mitral stenosis Subvalvular (Shone’s) Supravalvular (core triatriatum) Tricuspid stenosis

Right sided obstructive lesion Pulmonary stenosis Subvalvular (Fallot’s tetralogy) Valvular congenital stenosis or atresia Supravalvular (hypoplastic pulmonary arteries) Tricuspid stenosis Subvalvular (DCRV, Ebestien) Valvular congenital stenosis Supravalvular (eustachian valve)

Eustachian valve

Double Chamber Right Ventricle (DCRV)

Mixing lesions Defects with mixing of oxygenated and deoxygenated blood Partial desaturation lead to compensatory in red cell mass and increase 2,3 DPG with increase in blood viscosity.

Left sided obstructive lesions Hypoplastic left heart syndrome (HLHS) Tricuspid atresia with transposed great arteries Double-inlet left ventricle IAA DORV (some variations)

Left sided obstructive lesions Complete mixing of systemic and pulmonary venous return Ventricular outflow directed primarily to the PA Systemic blood flow (Qs) Largely by right-to-left ductal shunting Dependent on the relative PVR and SVR Systemic outflow obstruction is poorly tolerated Usually accompanied by signs or symptoms of shock

Left sided obstructive lesions Maintain preload at maximum Maintain afterload at maximum Maintain contractility in neonates at maximum Maintain below maximum contractility in older patients Relative bradycardia is preferred not in neonates Quick guide to pediatric cardiopulmonary care, edwards

Right sided obstructive lesions

Right sided obstructive lesions Tricuspid atresia Pulmonary atresia with IVS TOF with pulmonary atresia Severe Ebstein’s anomaly of the tricuspid valve Critical PS DORV (some variations)

Right sided obstructive lesions Complete mixing of systemic and pulmonary venous return Ventricular outflow predominantly directed out the aorta Low pulmonary blood flow (Qp) in single-ventricle patients implies an obligate right-to-left shunt (generally atrial level) Clinical consequences of low Qp are variable

Adjust PVR SVR balance to gain optimal oxygen delivery Mixing lesions Qp/Qs dependent upon PVR SVR balance Hypoxemia and its consequences Adjust PVR SVR balance to gain optimal oxygen delivery

Obstructive lesions Qp decreased Hypoxemia RV hypertrophy RV dysfunction TR Qs decreased Low CO Hypotension Coronary perfusion decreased LV failure Avoid SVR decrease Maintain preload Maintain PDA patency Avoid increase PVR Hyperoxia Hypoventilation Avoid decrease PVR Relative hypoxia Relative hypercarbia

Objectives Obstructive lesions right or left Mixing lesions Shunt lesions left to right or right to left Univentricular physiology Miscellaneous Anomalies of coronary arteries Vascular ring

Shunt lesions Shunts may intracardiac or extracardiac Large shunts are non restrictive with low pressure gradient across Small shunts are restrictive with high pressure gradient across

Left to right shunt Factors affecting shunt flow Ventricular or Great artery level Atrial level Relative compliance Right vs Left ventricle Pressure gradient between chambers or arteries Size of defect Ratio of PVR to SVR Blood viscosity

Left to right shunt Pathology of shunt flow Atrial or ventricular shunts Great artery shunts All shunts ↑RV filling ↑Pulmonary blood flow ↑LA and LV blood flow ↓Diastolic BP ↓Coronary perfusion pressure ↑RVEDV and ↑RVEDP Pulmonary edema ↑LVEDV and ↑LVEDP RV failure ↑PVR Myocardial ischemia LV failure Pulmonary hypertension Shunt reversal Eisenmenger’s syndrome RV hypertrophy Pressure RV > LV

Left to right shunt Pathology of shunt flow Avoid decrease in PVR Enhance the use of vasoconstrictors Avoid increase in pulmonary flow Avoid decrease in systemic flow Avoid extensive diastolic hypotension Avoid increase in total blood volume

Pulmonary artery banding

Pulmonary artery banding Good banding High pressure gradient across band by echo Non-congested lung fields

Objectives Obstructive lesions right or left Mixing lesions Shunt lesions left to right or right to left Univentricular physiology Miscellaneous TGA Anomalies of coronary arteries Vascular ring

Transposition of great arteries Mixing is mandatory for life Left ventricle mass and function Coronary anatomy

Coronary Anomalies ALCAPA

Vascular ring

Vascular ring AIR

Determinants of cardiac output preload Afterload Heart rate CNTRACTILITY CARDIAC OUTPUT Arterial O2 content OXYGEN DELIVERY OXYGEN extraction Venous saturation

Demons Angels Septal aneurysm Persistent left SVC Interrupted IVC Restrictive VSD High pressure gradient across VSD Law pressure gradient across left or right obstructive lesions Atralization of the RV Parachute mitral valve Interrupted aortic arch Non-restrictive VSD Law pressure gradient across VSD High pressure gradient across left or right obstructive lesions