Congenital Heart Defects Flashcards
Hypoplastic Left Heart Syndrome
occurs when parts of the left side of the heart (mitral valve, left ventricle aortic valve, and aorta) do not develop completely. The condition is congenital (present at birth).
Congenital Heart Defects
Heart defect is a cardiac lesion present in neonates Structural problems that arise from abnormal formation of the heart or major blood vessels
Etiology
Fetal heart develops b/t 4th and 7th week gestation Development can be affected by environment, genetics, and chromosomal abnormalities
Intrinsic/Extrinsic Nongenetic Risk Factors
Paternal Anesthesia = TOF 3.6% Sympathomimetic medication = COA 5.8%
Pesticides = VSD 5.5% Solvents = HPLSH 4.6%
Smoking 1 month prior pregnancy or in 1st trimester = Septal defect Heavy smokers >25 cigarettes daily = twice likely have septal defect Air pollutants during 1st trimester – ASD, VSD, TGA and TOF Obesity Low folic Acid = TGA Pregestational Diabetes Mellitus
Types
Acyanotic - no deoxygenated or poorly oxgenated blood enters the systemic circulation
Cyanotic - deoxygenated blood enters the systemic circulation
Acyanotic Disorders
Left-to-Right shunt through abnormal opening (arterial to venous) Patent ductus arteriosis Atrial septal defects Ventricular septal defects
Cyanotic Disorders
Cyanotic - Right to Left Shunts (venous to arterial) Tetralogy of Fallot Tricuspid atresia Transposition of the great vessels Truncus arteriosus Hypoplastic left heart syndrome Total anomalous pulmonary venous communication
Signs and Symptoms
Acynotic and Cyanotic Increased respiratory rate and/or effort Poor feeding with fatigue during feeding Excessive sweating Decreased exercise tolerance Primarily Cyanotic Cyanosis – oxygen saturation <85% Recurrent respiratory infections Squatting with fatigue Chest pain * severe aortic stenosis Syncope
PE Findings Acyanotic vs Cyanotic
Acyanotic: tachycardia, tachypnea, hepatomegaly, puffy eyelids, wheezing/rales, pallor/mottling, weak palpable peripheral pulse, gallop rhythm, cyanosis Cyanotic: cyanosis, pallor, abnormal resp patterns, tachycardia, abnormal heart sounds, peripheral pulses decreased and unequal, hypotension, clubbing of fingers and toes, poor growth
Dx Tests
Chest xray to evaluate heart size and pulmonary vascular markings EKG to evaluate rhythm, chamber enlargement or hypertrophy Arterial blood gas and hemoglobin with cyanosis Echocardiogram for diagnosis of specific congenital heart defect
Treatment Plan
Prompt referral to pediatric cardiologist all children with congenital heart defect should be followed by cardiology or CT specialists
Manifestations
PDA and small ventricular defects may close spontaneously, may have no signs or symptoms Severe defects may cause pulmonary congestion, cardiac failure, and decreased peripheral perfusion. which may lead to Cyanosis, respiratory distress, and fatiguability may lead to poor feeding and failure to thrive
Atrial Septal Defects
Result of improper septal formation in fetal development More frequently found in females than males Most are small and found inadvertently Most children are asymptomatic Adolescents may have atrial fibrillation or flutter due to atrial dilatation that occurs In severe cases, closure may be needed
Patent Ductus Arteriosus (PDA)
Usually closes 24- to 72 hours post partum Size of opening varies Treatment either pharmacological or surgical Prostaglandin inhibitors (ibuprofen, indocin) Teflon plug, umbrella, or coil in cath lab Ligation thorascopically
Ventricular Septal Defect (VSD)
Due to incomplete separation of ventricles during fetal development Most common congenital heart defect comprising 20-30% May be asymptomatic until 4 to 25 weeks of life, when pulmonary vascular resistance falls Size of opening determines severity of symptoms (murmur to heart failure) Small defects may close spontaneously, larger defects may require closure
Pulmonary Stenosis
May be isolated valve lesion (absent or malformed cusps) or found in Tetralogy of Fallot Increased workload on right side of heart Most children asymptomatic Severe defects worsen as child grows Treatment aimed at maintaining patent ductus to perfuse lungs In presence of multiple heart defects, the increased pressure could delay closure of foramen ovale Valve repair may be required
Coarctation of the Aorta (COA)
Narrowing of the aorta either pre or post ductal Boys twice as likely as girls to have this defect Symptoms present at 2 weeks of age May be a feature of Turner’s syndrome Classic sign is disparity in pulses in upper and lower extremities Significant coarctation should be treated surgically age 2 to 4 Untreated – life expectancy 20 to 40 years
Tetralogy of Fallot (TOF)
Tetralogy of Fallot “blue babies” Consists of 4 congenital heart defects Ventricular septal defect Dextroposition or right shifting of aorta Obstruction of pulmonary outflow channel Hypertrophy of the right ventricle Surgical repair is advised for all children with this diagnosis
Transposition of the Great Arteries (TGA)
Aorta originates in the right ventricle Pulmonary artery originates in the left ventricle More common in boys and in infants whose mother’s have diabetes Survival dependent on communication of right and left sides of heart Medication may be given to keep ductus open or balloon septoplasty performed to enlarge foramen ovale Corrective surgery essential for long-term survival
HLHS Patho
a related group of anomalies that include underdevelopment of the left side of the heart (e.g. atresia of the aortic or mitral orifice) and hypoplasia of the ascending aorta. The left ventricle may be small and nonfunctional or totally atretic. The right ventricle maintains both pulmonary and systemic circulations. Pulmonary venous blood passed through an atrial defect or dilated foramen ovale from the left to the right side of the heart, where it mixes with systemic venous blood (TOTAL MIXING LESION). The ventricular septum is usually intact.
HLHS S&S
Most infants are diagnosed in the first few hours or days of life. A grayish blue color of the skin is soon apparent (denoting a mix of cyanosis and hypoperfusion). If the PDA partially closes, signs of systemic hyporperfusion and shock predominate. Signs of HF usually appear within the first few days or weeks of life (dyspnea, hepatomegaly, low cardiac output). Peripheral pulses may be weak or absent. Cardiac enlargement is usual, with a right ventricular parasternal lift. A nondescript systolic murmur is usually present.
HLHS Dx Tools
CXR shows cardiomegaly Electrocardiogram - Initially, may show only the normal right ventricular predominance.Later, P waves become prominent and right ventricular hypertrophy is usual. Echocardiogram: Is diagnostic. There is absence or hypoplasia of the mitral valve and aortic root, a variable small left atrium and left ventricle, and a large right atrium and right ventricle. The size of the atrial communication can be assessed directly and by pulsed and color flow Doppler studies.
HLHS Tx
Norwood Procedure Cardiac Transplant Supportive Expectant Care
