Congenital Heart Defects PDF

Congenital Defects of the Heart Dr Vijay Paul Samuel [email protected]  Learning outcome Outline the steps in the normal development of heart chambers and relate to congenital heart diseases.  Congenital Heart Defects Heart a...

Congenital Defects of the Heart Dr Vijay Paul Samuel [email protected]  Learning outcome Outline the steps in the normal development of heart chambers and relate to congenital heart diseases.  Congenital Heart Defects Heart and vascular abnormalities make up the largest category of human birth defects Present in ∼ 1% of live born infants. ∼ 12% of babies with heart defects have a chromosomal abnormality ∼ 33% of babies with a chromosomal abnormality have a heart defect. ∼ 30% of heart defects occur in infants with other major malformations. ∼ 2% of heart defects are due to environmental agents. Most caused by a complex interplay between genetic and environmental influences (multifactorial causes).  heart Defect Congential Congenital Heart Defects Acyanotic heart defects E Let to Titans Right shunting rightolett cardiacstent A group of heart anomalies that result in left-to-right shunting. Cyanotic heart defects Cyanotic heart defects are characterized by a right-to-left cardiac shunt, which leads to deoxygenated blood entering the systemic circulation. deoxygenated blood will enter the In cyanotic heart defeat the systemic circulation  because the defect characterised by LefttoRight to left cardiac Acyanotic congenital heart defects right shunt defect The most common include Atrial Septal defect Ventricular septal defect. ventrical septal Atrial septal defect. from left to right Patent ductus arteriosus. ductus arteriosus Patent tort of T Coarctation of aorta. coarctation mostont result in left to rightshuntin Ventricular Septal Defects An abnormal communication between the left and right ventricle that results in left-to-right shunting Most common congenital heart defect (∼ 4/1000 live births) Occurs as an isolated heart defect or in combination with others (e.g., AVSD, tetralogy of Fallot, TGA) Most commonly located in the membranous part of the ventricular septum Defect in ventricular septum → left-to-right shunt T RV volume overload → RV hypertrophy f aaatiEnn'tiana Excessive pulmonary blood flow → ↑ pulmonary artery pressure → pulmonary Ed hypertension ↓ Cardiac output out heartfate LV volume overload → LV hypertrophy I cardon causealso hypertensive pulmonary  Ventricular Septal Defects A defect in the ventricular septum leads to a left-to-right shunt, the volume of which is dependent on the size of the defect. Blood flows from the left ventricle to the right ventricle (white arrow) along the pressure gradient from will more blood to kinda Atrial Septal Defect initial Defect in the interatrial septum Atrial left-to-right shunt RA and RV volume overload 0 Impaired growth or excessive resorption of the atrial septa Ostium primum atrial septal defect (ASD I): ∼ 15–20% (usually accompanied by other heart defects) 00 Ostium secundum atrial septal defect (ASD II): ∼ 70% (usually isolated) ASD → oxygenated blood shunting from LA to RA → ↑ O2 saturation 20 oct in the RA → ↑ O2 saturation in RV and pulmonary artery ASD II/ostium secundum atrial septal defect ASD II/ostium secundum E atrial septal defect is the excessive resorption of the E septum primum or impaired growth of the septum secundum. The defect is located in the fossa ovalis, in the cranial E part of the atrial septum. cranial part of atrial septum tosaol.lt  Patent foramen ovale (PFO) PFI Foramen ovale remains patent beyond 1 year of age EE Failure of the atrial septum primum to fuse with the septum secundum following birth → persistence of foramen ovale → mild left-to-right shunt A right-to-left shunt (i.e., shunt reversal) may be induced by certain maneuvers that increase right atrial pressure (e.g., Valsalva maneuver, coughing) m  Coarctationottone Coarctation of Aorta 1) Stenosis distal to the left subclavian artery results in hypertension (↑ BP) in the upper extremities and the head, and hypotension (↓ BP) in the lower extremities and abdomen. (2) If coarctation involves the origin of the left subclavian artery, BP in the D right arm and head will be higher than in the left arm, lower extremities, and abdomen.  Ends happen Coarctation of Aorta Time Narrowing of the aorta at the aortic isthmus or, rarely, in the F descending thoracic or abdominal aorta Tunica medial thickening and intimal hyperplasia → formation of a ridge encircling the aortic lumen → narrowing of the aorta → ↑ __ flow proximal to the narrowing and ↓ flow distal to the narrowing Coarctation most commonly occurs distal to the left subclavian artery. Left ventricular outflow obstruction → myocardial hypertrophy and increased collateral blood flow (e.g., intercostal vessels, scapular vessels). In severe cases → hypoperfusion of organs and extremities distal to the stenosis D Patent Ductus Arteriosus Agnote In patent ductus 9 arteriosus, there is a left- to-right shunt, with blood flowing from the aorta to the pulmonary arteries during both systole and diastole to pulmonary Aortata blood flowfrom arteries during systole  Patent Ductus Arteriosus a feb1th Failure of the ductus arteriosus to completely close postnatally Ductus arteriosus enables the underdeveloped lungs to be bypassed I by the fetal circulation (normal right-to-left shunt) After birth, pulmonary vascular resistance decreases and thus allows for the reversal of the shunt from right-to-left to left-to-right. Failure of the ductus arteriosus to close after birth → persistent communication between the aorta and the pulmonary arterycausinghett → left-to-right shunt → volume overload of the pulmonary vessels F → continuous RV (and/or LV) strain → heart failure money to rightshunt saeyvomasvertfad.tw utt FEE Cyanotic Heart Defects(CHD) Tetralogy of Fallot TOE Transposition of Great Arteries(Vessels) Include Persistent truncus arteriosus Tricuspid valve atresia Ebstein anomaly  rightventriclehypotrophy Tetralogy of Fallot (TOF) why SIic becausetherewill bemixingof oxygenate anddeoxygenated blood  Rightaticatisthow Tetralogy of Fallot (TOF) ventricularhypertrophy ventricularseptaldefect Concurrent existence of the following four defects: overridingAorta 1. Right ventricular outflow tract obstruction (RVOTO) due to pulmonary infundibular stenosis 2. Right ventricular hypertrophy (RVH) 3. Ventricular septal defect (VSD) 4. Overriding aorta (the aorta is displaced above the VSD) The most common cyanotic CHD. congistedheartDisease outflow Rightventral Physiologic blood flow is determined by the severity of RVOTO. tract obstruction A large VSD → equal pressures in the right and left ventricles → blood flow along the path of least resistance to Severe RVOTO → flow from RV to LV → desaturated blood entering the circulation via the aorta ITE Enumerate T.IE ttii bloodcirculation via theanode Persistent Truncus Arteriosus Tract truncus Mixing of bloodthat's why it's synotic coat  No Aorticopulmonary septum mitin a.ie Persistent Truncus Arteriosus Underdevelopment of the aorticopulmonary septum transposition → failure of the truncus arteriosus to divide into the aorta and pulmonary trunk → a single trunk that receives output from both ventricles The failure of neural crest cells to migrate during the development of the cardiac outflow tract results in incomplete AP septum formation. Deoxygenated and oxygenated blood mix via the VSD → the truncus arteriosus receiving both RV and LV output → blood flow to both pulmonary and systemic circulations Dresuttinginni bloooxygegofnated and deoxygenated to the pulmonary and systemic circulation Transposition of Great Vessels ifeng.tw o Anatomical reversal of the aorta and the pulmonary artery Accounts for ∼ 20% of all cyanotic CHD cases o Failed spiraling of the aorticopulmonary septum → RV emptying into the aorta and LV into the pulmonary artery EFF → complete isolation of the pulmonary and systemic circuits → ↓ oxygenated blood entering the systemic circulation Transposition of greatvessel Anatomical reversal of Aorta pulmongasty Said spiraling of APIeptum result in RVemptyingin LV empty in the anoda pulmonyarty oxygenated blood this resultin low  a by the Sys Transposition of Great Vessels In transposition of the great vessels, deoxygenated blood enters the systemic circulation. Survival after birth is only possible via an intracardiac shunt (e.g., across a patent ductus arteriosus and/or a patent foramen ovale). suggestion to iii IT  Aterilaration oftheventricle Ebstein Anomaly IE Malformed tricuspid valve leaflets that are displaced into the right ventricle with subsequent tricuspid valve regurgitation and right heart enlargement (known as RV “atrialization”) Incomplete closure of the right atrioventricular valve and reduction in RV volume fttEFts → tricuspid regurgitation→ RA dilation → right heart failure Bulging of the large sail-like anterior tricuspid leaflet into the RV → RVOTO O.F.am → ↑ right heart pressure → ↑ flow through the patent foramen ovale → right-to-left shunt → cyanosis  Ebstein anomaly so in iiiii themftp.sina.se reading not measure I evidenced KEEF Holt-Oram syndrome Mutations in the TBX5 gene Erol Es characterized by preaxial (radial) limb abnormalities and ASDs. Defects in the muscular portion of the interventricular septum may also occur. Isftim o TBX5 regulates forelimb development and plays a role in septation of the heart. Holt-Oram syndrome is inherited as an autosomal dominant trait w/ith a frequency of 1/100,000 live births. 713 5 gener causing nheretiedasautosomal HO.IO forelimb development dominant mutation TBYe