Congenital Cardiovascular Anomalies PDF

Congenital Cardiovascular Anomalies Dr. Babazadeh, Ped Inteventional Cardiologist Babol Medical University  Classification of CHDs 1. Structural heart defects due to abnormal development of the heart during the first 2 months after conception 2. Functional...

Congenital Cardiovascular Anomalies Dr. Babazadeh, Ped Inteventional Cardiologist Babol Medical University  Classification of CHDs 1. Structural heart defects due to abnormal development of the heart during the first 2 months after conception 2. Functional heart defects e.g.: congenital heart block 3. Positional heart defects e.g.: dextrocardia  LVH Inc. PBF RVH BVH Acyanotic LVH RVH Dec. PBF BVH LVH CHDs RVH Inc. PBF BVH LVH Cyanotic RVH Dec. PBF BVH  Non cyanotic CHDs Volume overload (most common) Pressure overload  1-Volume overload lesions Left to right lesions (most common): ASD, VSD. AVSD, PDA. AV and semilunar valves regurgitation: AVSD, Ebstein anomaly, AI with supracrystal VSD. Cardiomyopathies: DCM, RCM, HCM. ASD VSD Ebstein anomaly  2-Pressure overload lesions Outlet obstructions (most common): AS, PS, COA. Inlet obstructions: MS, TS, Cortriatriatum.  Cyanotic CHDs Dec. PBF obstruction to PBF and Rt. To Lt. shunt: TAt., TOF, SV. with PS. Inc. PBF 1-incorrect association between GAs and ventricles: TGA 2-complete mixing of systemic and pulmonary circulation in the heart: Common atrium or ventricle, TAPVR, TA.  Classifications of Structural Congenital Heart Defects Increased Decreased Obstruction to Pulmonary Pulmonary Systemic Blood Blood Flow Blood Flow Flow ASD Tetralogy of Fallot Coarctation of the PDA Transposition of the Aorta VSD Great Arteries Aortic Stenosis AV Canal Pulmonary Stenosis Hypoplastic Left Total Anomalous Pulmonary Atresia Heart Syndrome Pulmonary Venous Tricuspid Atresia Mitral Stenosis Return Truncus Arteriosus  Shunts Right to Left vs. Left to Right Right to left shunt: un-oxygenated blood is shunted from the right side of the heart to the left side, and then enters the systemic circulation. Left to right shunt: a portion of the oxygenated blood is shunted from the left side of the heart to the right side and enters the pulmonary circulation, increasing the work load for the right heart.  Cyanotic vs. Acyanotic Acyanotic (usually left to right shunts): – PDA, ASD, VSD. Cyanotic (right to left shunts): – TOF, Transposition of the Great Arteries, Hypoplastic Left Heart syndrome – O2 Sat less than 95% – Child may have chronic hypoxia – Caused by: Decreased pulmonary blood flow –and/or-- Right-to-left shunting: de-oxygenated blood is shunted from the right side of the heart to the left side without traveling through the pulmonary circulation, and blood that eject from the left side of the heart to the systemic circulation is only partly oxygenated Most Common Congenital Heart Defects These account for 85% of all CHDs: Atrioventricular Septal Defect Coarctation of the 9% Aorta 10% Tetralogy of Fallot 44% 12% Transposition of the 10% Great Arteries 15% Ventricular Septal Defects All other congenital heart defects  Some Statistics Most common birth defects – 30% of all congenital birth defects. Most common cause of infant death in children dying because of a birth defect.  Etiology of CHD Unknown Incidence of CHD in children is slightly increased if siblings or parents have CHD Gender Factors Environmental Factors Genetic Factors  Gender Factors Generally occur equally among males and females, but— – More common in males: aortic stenosis, coarctation of the aorta – More common in females: PDA, ASD  Environmental Factors Maternal Infections: – Rubella: PDA, pulmonary stenosis, VSD, ASD Maternal Drugs: – Lithium: Tricuspid valve abnormalities, Ebstein’s Anomaly – Possibly related to CHDs: Dilantin & Cocaine – Alcohol abuse: VSD Maternal Disease: – Diabetes: transposition of the great vessels, VSD, situs inversus, single ventricle, hypoplastic left ventricle – SLE: Congenital heart block  Genetic Factors Trisomy 21 (Down’s Syndrome): A-V canal defects, VSD XO (Turner’s Syndrome): coarctation of the aorta, aortic stenosis Osteogenesis Imperfecta: Aortic incompetence Marfan Syndrome: Aortic dilatation, aortic & mitral incompetence  Prevention of CHD Not possible in most cases But -- there are options a woman can take to reduce her risk of having a child with CHD: – Abstain from alcohol during pregnancy – Be immunized against rubella before conception – If diabetic, maintain tight control of blood sugars – Folic acid 400 mcg/daily before conception may help to prevent CHD (unproven) – If there is a family history of CHD genetic counseling prior to conception Embryonic Heart Development The heart develops in the embryo during post-conception weeks 3 - 8  Beginning Development Early week 3 post-conception: heart begins as 2 endothelial tubes Mid-week 3 : endothelial tubes fuse to form a tubular structure 28 days following conception: the single- chambered heart begins pumping blood  Week 4 Heart has: – single outflow tract, the truncus arteriosus (divides to form aorta & pulmonary arteries) – Single inflow tract, the sinus venosus (divides to form the superior and inferior vena cavae) – Single atrium – Single ventricle – AV canal begins to close  Weeks 5 - 7 Week 5 Week 7 AV canal closure Ventricular septum fully complete developed Formation of atrial and Coronary Sinus forms ventricular septums Outflow tracts (aorta & Heart growing rapidly, pulmonary truck) fully and folds back on itself to separated form its completed anatomic shape  8 Weeks After Conception By the end of the 8th week after conception the fetus has a fully developed 4-chambered heart  Fetal Circulation Before birth the placenta provides the oxygen needed by the developing fetus— the lungs receive only enough blood to perfuse the lung tissues due to high pulmonary vascular resistance & fetal vascular shunts  Fetal Circulation Arterial blood in the fetus: – enters the fetal circulation via the umbilical vein: – passes through the ductus venosus and enters the inferior vena cava – flows into the right atrium and passes through the foramen ovale into the left side of the heart – passes from the right side of the heart, through the ductus arteriosus to enter the systemic circulation, bypassing the pulmonary circulation  Fetal Circulation Venous blood in the fetus: – returns to the placenta through the 2 umbilical arteries  After Birth Lungs distend with air and pulmonary vascular resistance falls. Pulmonary blood flow increases The foramen ovale and ductus venosus usually close during the first day of life The ductus arteriosus usually closes during the first 24 – 72 hours of life  Signs/Symptoms of CHD Murmurs Cyanosis –worsens with crying or other exertion Respiratory distress Signs of poor perfusion, such as slow capillary refill, diminished peripheral pulses Fatigue – commonly observed during feedings in newborns or during play in children Failure to thrive Common Congenital Heart Anomalies Patent Ductus Arteriosus (PDA) Usually closes within 24 to 72 hours after birth Closure of the ductus may be delayed, or not occur at all in preterm infants PDA causes increased pulmonary blood flow, pulmonary congestion, increases the workload of the right ventricle; causes increased pulmonary venous return and increases workload of the right ventricle PDA  Localized narrowing of the aorta More common in males than females Associated with Turner’s Coarctation of Syndrome the Aorta Most common clinical sign: weak pulses & decreased blood pressure in the lower extremities  Most common congenital heart defect May occur alone, or VSD with other abnormalities About one-third of small VSDs will close spontaneously  Truncus fails to divide completely during fetal life, leaving a connection between Truncus the aorta and pulmonary arteries Arteriosus Mixed oxygenated and de-oxygenated blood exits the heart and enters the systemic circulation  TOF = – Ventricular septal defect – Aorta position is Tetralogy of shifted to the right and over-rides the VSD Fallot – Stenosis of the pulmonary outflow tract, often involving the pulmonary valve – Hypertrophy of the right ventricle  The aorta originates from the right ventricle; the pulmonary artery originates from the left Transposition of ventricle the Great Vessels A PDA is necessary for these infants to survive until they can have corrective surgery More common in infants of diabetic mothers  Fatal without early surgical intervention May be associated with other congenital Hypoplastic Left anomalies Heart  The pulmonary veins, instead of being connected to the left ventricle, are TAPVR connected to the right ventricle or superior vena cava, and return oxygenated blood to the right side of the heart.  Includes: – ASD – VSD – Abnormalities of the AV Canal Mitral and/or Tricuspid valves Greater incidence in children with Down’s Syndrome  May occur: – With Situs Inversus: carries a slightly increased risk of heart defects (~ 5 – 10% associated with other Dextrocardia CHDs) – Without Situs Inversus: carries a greatly increased risk of associated heart defects (~95% associated with other CHDs) Both conditions are EXTREMELY rare