Congenital Diseases Dr. Gerrard Uy

Congenital Heart Disease 0.5-0.8% of live births incidence is higher in stillborns (3-4%), abortuses (10-25%), and premature infants (about 2%) diagnosis is established by 1 wk of age in 40-50% of patients with congenital heart disease and by 1 mo of age in 50-60%

Etiology Result of aberrant embryonic development of a normal structure or failure to progress beyond an early stage of embryonic or fetal development

Pathophysiology The anatomic and physiologic changes in the heart and circulation due to any CHD are not static Progress from prenatal life to adulthood Consequences: Pulmonary hypertension Erythrocytosis Pregnancy related complications Infective endocarditis

Relative frequency of Major Congenital lesions Ventricular septal defect25-30 Atrial septal defect (secundum)6-8 Patent ductus arteriosus6-8 Coarctation of aorta5-7 Tetralogy of Fallot5-7 Pulmonary valve stenosis5-7 Aortic valve stenosis4-7

Relative Frequency of Major Congenital lesions d-Transposition of great arteries3-5 Hypoplastic left ventricle1-3 Hypoplastic right ventricle1-3 Truncus arteriosus1-2 Total anomalous pulmonary venous return1-2 Tricuspid atresia1-2 Single ventricle1-2 Double-outlet right ventricle1-2 Others5-10

Fetal circulation

Congenital Disease Most congenital defects are well tolerated in the fetus because of the parallel nature of the fetal circulation only after birth when the fetal pathways (ductus arteriosus and foramen ovale) are closed that the full hemodynamic impact of an anatomic abnormality becomes apparent

Etiology Cause is unknown There is progress in identifying genetic basis of many congenital heart lesions small percentage - related to chromosomal abnormalities, in particular, trisomy 21, 13, and 18 and Turner syndrome 2-4% -associated with known environmental or adverse maternal conditions and teratogenic influences, including maternal diabetes mellitus, phenylketonuria, or systemic lupus erythematosus

diabetic mothers are five times more likely to have congenital cardiovascular malformations most congenital heart disease is still relegated to a multifactorial inheritance pattern Fetal echocardiography improves the rate of detection

2 major groups Acyanotic Congenital heart lesions

Acyanotic Congenital heart lesions Increased volume load: ASD (atrial septal defect) VSD (ventricular septal defect) AV septal defects PDA (patent ductus arteriosus) Increased pressure load: valvular pulmonic stenosis valvular aortic stenosis coarctation of the aorta

Cyanotic Congenital heart lesions Decreased Pulmonary Blood Flow - obstruction to pulmonary blood flow and a pathway by which systemic venous blood can shunt from right to left and enter the systemic circulation tricuspid atresia Tetralogy of Fallot single ventricle with pulmonary stenosis Increased Pulmonary Blood flow Transposition of the great vessels Total anomalous pulmonary venous return Truncus arteriosus

PDA (patent ductus arteriosus)

Pathophysiology blood shunts left to right through the ductus from the aorta to the pulmonary artery pulmonary artery pressure may be elevated to systemic levels during both systole and diastole risk for the development of pulmonary vascular disease if left unoperated

Manifestations small patent ductus does not usually have any symptoms large PDA will result in heart failure Cardiac enlargement Classic continuous murmur (machinery-like)

Diagnosis ECG Xray 2D echocardiography Left ventricular hypertrophy prominent pulmonary artery with increased intrapulmonary vascular markings 2D echocardiography left atrial and left ventricular dimensions are increased Visualization of the patent ductus

Treatment Irrespective of age, patients with PDA require surgical or catheter closure should not be unduly postponed after adequate medical therapy for cardiac failure has been instituted thoracoscopic techniques to minimize scarring and reduce postoperative discomfort

Atrial Septal Defect

Atrial Septal Defect Occurs more frequently in females 3 types: Sinus venosus – near the entry of the superior vena cava into the right atrium Ostium primum – lie adjacent to the atrioventricular valves, common in Down’s syndrome Ostium secundum – most common and involves the fossa ovalis

Ventricular Septal Defect

Ventricular Septal Defect Opening is usually single Situated in the membranous portion of the septum Spontaneous closure is more common in patients born with a small VSD Operative correction or transcatheter closure is indicated when there is moderate to large left to right shunt

Acyanotic CHD without a shunt Valvular aortic stenosis More common in males than in females One of the most common congenital malformations of the heart

Coarctation of the Aorta

Acyanotic CHD without a shunt – Coarctaion of the Aorta Coarctation of the Aorta May occur anywhere but is most common distal to the origin of the left subclavian artery Occurs in ~7% of patients with CHD More common in males Frequent in patients with Turner’s syndrome 10% have circle of willis aneurysms Manifestations: Epistaxis, headahce, cold extremities, and claudication Hypertension in the upper extremities Absence or delayed pulsations in the femoral arteries

Cyanotic CHD – Tetralogy of Fallot

Tetralogy of Fallot 4 components: ECG shows RV hypertrophy Malaligned ventricular septal defect Obstruction to RV outflow Aortic override of the VSD RV hypertrophy ECG shows RV hypertrophy CXR shows boot shaped heart (coeur en sabot)

Cyanotic CHD- Transposition of the Great Arteries

Transposition of the Great Arteries Commonly called dextro- or D-transposition of the great arteries The aorta arises rightward anteriorly from the right ventricle and the pulmonary artery from the left ventricle More common in males Accounts for ~10% of cyanotic CHD

Other Cyanotic Congenital Heart Disease Single Ventricle Tricuspid Atresia Characterized by atresia of the tricuspid valve, interatrial communication and hypoplasia of the right ventricle and pulmonary artery Ebstein Anomaly Characterized by downward displacement of the tricuspid valve into the right ventricle