Congenital Heart Disease

Aetiology and incidence The incidence 0.8% of live births. Maternal infection or exposure to drugs or toxins may cause congenital heart disease. Maternal rubella infection is associated with persistent ductus arteriosus, pulmonary valvular stenosis, and atrial septal defect. Maternal alcohol misuse is associated with septal defects, and maternal lupus erythematosus with congenital complete heart block. Genetic or chromosomal abnormalities such as Down’s syndrome may cause septal defects. Divided into noncyanotic (L  R) and cyanotic (R  L) categories based on direction of shunting

Incidence of congenital cardiac malformation Ventricular septal defect 30 Atrial septal defect 10 Patent ductus arteriosus 10 Pulmonary stenosis 7 Coarctation of aorta 7 Aortic stenosis 6 Tetralogy of Fallot 6 Complete transposition of great arteries 4

Noncyanotic CHD (L  R) Atrial septal defects (ASD) Ventricular septal defects (VSD) Patent ductus arteriosus (PDA) Obstruction to blood flow Pulmonic stenosis (PS) Aortic stenosis (AS) Aortic coarctation

Atrial Septal Defect

Three major types Ostium secundum most common In the middle of the septum in the region of the foramen ovale Ostium primum Low position Form of AV septal defect Sinus venosus Least common Positioned high in the atrial septum

ASD (atrial septal defect) Clinical Features Most children are asymptomatic for many years and the condition is often detected at routine clinical examination Qi/Qs > 1.5: symptoms (+) Effort dyspnea (exercise intolerance) Palpitation (Af/AF) Paradoxical embolism Pulmonary hypertension Eisenmenger syndrome

Atrial Septal Defect. signs : Right ventricular heave S 2 widely split and usually fixed Systolic murmur at left 2 nd insterconstal space mid-diastole rumble at LLSB (tricuspid flow)

Eisenmenger’s syndrome If severe pulmonary hypertension develops, a left-to-right shunt may reverse, resulting in right-to-left shunt and marked cyanosis with clubbing.

ASD (atrial septal defect) EKG: SR / Af / AF; RBBB CXR: cardiomegaly, dilated PA Echo: TTE, TEE Cath: Qp / Qs, PA pressure

Atrial Septal Defect Treatment Closure generally recommended when ratio of pulmonary to systemic blood flow (qP/qS) is > 1.5:1 Closure can also be accomplished at cardiac catheterisation using implantable closure devices.

Ventricular Septal Defect Single most common congenital heart malformation, accounting for almost 30% of all CHD Defects can occur in both the membranous portion of the septum (most common) and the muscular portion

Ventricular Septal Defect

Two major types Small, All close spontanously 90% by 6 years Large VSDs with normal PVR Usually requires surgery, otherwise… Will develop CHF. Ventricular Septal Defect

Clinical features Asymptomatic may present as cardiac failure in infants. rarely as Eisenmenger’s syndrome Systolic thrill and Harsh pansystolic murmur heard best at the left sternal border with radiation over the entire precordium.

Treatment Small ventricular septal defects require no specific treatment. Cardiac failure in infancy is initially treated medically with digoxin and diuretics. Persisting failure is an indication for surgical repair of the defect. Percutaneous closure devices are under development Ventricular Septal Defect

Patent Ductus Arteriosus Persistence of normal fetal vessel joining the pulmonary artery to the aorta.

Normally, the ductus closes soon after birth but sometimes fails to do so. Accounts for about 10% of all cases of CHD. More common in females Patent Ductus Arteriosus

Clinical Features Clinical findings and course depend on size of the shunt and the degree of associated pulmonary hypertension. With small shunts there may be no symptoms for years, but when the ductus is large, growth and development may be retarded. Usually there is no disability in infancy but cardiac failure may eventually ensue. Patent Ductus Arteriosus

Pulses are bounding and pulse pressure is widened A continuous ‘machinery’ murmur is heard with, maximal in the second left intercostal space below the clavicle. Patent Ductus Arteriosus

Treatment consists of surgical correction when the PDA is large. Transcatheter closure of small defects has become standard therapy In preterm infants indomethacin is used (80- 90% success in infants > 1200 grams) Patent Ductus Arteriosus

Narrowing of the aorta occurs in the region where the ductus arteriosus joins the aorta, i.e. at the isthmus just below the origin of the left subclavian artery The condition is twice as common in males Simple coarctation: Complex coarctation: combine other lesions (bicuspid aortic valve, intracranial aneurysm) Coarctation of the aorta

Clinical Features: Epistaxis,headache, leg weakness on exertion Leg claudication is rare Brachial pressure> popliteal pressure 10mmHg The BP is raised in the upper body but normal or low in the legs. The femoral pulses are weak, and delayed in comparison with the radial pulse A systolic murmur is usually heard posteriorly, over the coarctation.

Chest X-ray in early childhood is often normal but later may show changes in the contour of the aorta (indentation of the descending aorta, ‘3 sign’) and notching of the under-surfaces of the ribs from collaterals. MRI is ideal for demonstrating the lesion. The ECG may show left ventricular hypertrophy.

Interventional indication: Arm > leg systolic BP 10mmHg Radial-femoral pulse delay Peak trans-coarctation pressure gradient >20mmHg Surgery Transcatheter Treatment

Cyanotic CHD (R  L) Tetralogy of Fallot (TOF) Tricuspid atresia (TA) Total anomalous pulmonary venous return (TAPVR) Truncus arteriosus Transposition of the great vessels

Tetralogy of Fallot VSD Overriding aorta RVOT obstruction(PS) RVH ASD (pentalogy)

Tetralogy of Fallot

Most common cyanotic lesion Clinical findings vary depending on degree of RVOFT obstruction Most patients are cyanotic by 4 months and it is usually progressive Hypoxemic spells (“tet spells”) are one of the hallmarks of severe tetralogy Clubbing Systlic ejection murmur at the upper LSB Tetralogy of Fallot

Investigations: ECG shows right ventricular hypertrophy and the chest X-ray shows an abnormally small pulmonary artery and a ‘boot-shaped’ heart. Echocardiography is diagnostic and demonstrates that the aorta is not continuous with the anterior ventricular septum

Tet spells most commonly start around 4 to 6 months of age and are charcterized by 1.Sudden onset or deepening of cyanosis 2.Sudden onset of dyspnea 3.Alterations of consciousness 4.Decrease in intensity of systolic murmur Tetralogy of Fallot

Treatment Surgical Repair may be staged (modified BT shunt) or complete. Tetralogy of Fallot