Congenital Heart Disease Flashcards
What genetic syndromes may predispose a fetus to congenital heart defects (CHD)?
Trisomy 21, Turner Syndrome, DiGeorge Syndrome
What role does the Csx/NKX2.5 gene play in heart defects?
If Csx/NKX2.5 is deleted, cardiac myocytes form, but their morphogenesis is arrested and growth of the heart tube is retarded leading to defects such as
- atrial/ventricular septal defects
- tetralogy of Fallot
- double-outlet right ventricle
- tricuspid valve abnormalities
- hypoplastic left heart syndrome
How are CHD classified?
- Acyanotic group
- Cyanose Tardive group
- Cyanotic group
Describe the acyanotic group of CHDs and give examples
Does not have abnormal communication betwixt systemic and pulonary circuits
- Coarctation of aorta
- Right-side aortic arch
- Ebstein malformation
Describe the cyanose tardive group of CHDs and give examples
Initial L to R shunt with late reversal of flow from R to L
- Patent Ductus Arteriosus
- Patent Foramen Ovale
- Ventricular Septal Defect
What is the name of the mechanism where the shunt is initiall L to R and then switches R to L?
Eisenmenger Complex
Describe the cyanotic group of CHDs and give examples
Permanent R to L shunt
- Tetralogy of Fallot
- Truncus Arteriosus
- Tricuspid Atresia
- Complete Transposition of the Great Vessels
What is the most common ventricular septal defect?
Partial/complete formation of the membranous portion of the septum
What is the name of the syndrome in which a patient has a double outlet right ventricle and a subpulmonic ventricular septal defect?
Taussig-Bing Syndrome
A patient with a small ventricular septal defect has resultant pulmonary artery thickening and increased pulmonary vascular resistance. What is the pathology that will likely occur?
The direction of the shunt is reversed from L to R to R to L causing late onset cyanosis (tardive cyanosis) RVH and RHF (Eisenmenger complex)
What percentage of adults have patent foramina ovale? What are the Syx?
25%; Generally asymptomatic
What type of emboli can occur in those with a patent foramen ovale?
Paradoxical embolus
What type accounts for 90% of Atrial Septal Defects?
Ostium Secundum Type
What is an ostium secundum?
A foramen in the septum primum
What is the name of the syndrome in which there is a combination of mitral stenosis and ostium secundum septal defect?
Lutembacher Syndrome
What flow anomaly occurs in sinus venosus defects?
Drainage of right pulmonary veins into the right atrium/superior vena cava
What atrioventricular canal defect is encountered in patients with Down Syndrome?
Persistent Common Atrioventricular Canal
A patient presents with enlarged ostium primum atrial septal defect, inlet ventricular septal defect, and clefts in the anterior leaflet of the mitral valve and septal leaflet of the tricuspid valve. What is the Dx?
Complete atrioventricular canal
What is an incomplete atrioventricular canal?
Ostium primum atrial septal defect is adjacent to the atrioventricular valves
What symptoms are seen in an adult with an atrial septal defect?
Cyanosis and clubbing of the fingers
What causes obliteration of the ductus arteriosus? What does it become?
Increased arterial oxygen content; Ligamentum Arteriosus
What situations are persistent ductus arteriosus found?
Pregnant mothers with rubella virus, premature infants, Downs, DiGeorge
Describe the pathophysiology of a patent ductus arteriosus
- Blood from the high pressure aorta is diverted
- Left Ventricular Hypertrophy ensues due to increased demand
- In severe PDA, pulmonary hypertension may occur
What is an aortopulmonary window defect?
A connection betwixt the aorta and the pulmonary trunk (artery)
Describe the malformation of the persistent truncus arteriosus. How many types of PTA are there?
There is an incomplete partition of the truncus arteriosusby the spiral septum resulting in a connected aorta and pulmonary trunk; 4
What would a physician hear if the heart of an infant with persistent truncus arteriosus was ascultated?
Torrential pulmonary blood flow
What are the main defects found in hypoplastic left heart syndrome?
Severe aortic valvular stenosis or aortic atresia
What are the clinical findings of a newborn with hypoplastic left heart syndrome?
Initially seems well, but when pulmonary resistance and systemic blood flow decreases, symptoms occur. There is an obligate L-R shunt thru patent foramen ovale. CO depends on flow of blood from RV thru patent ductus arteriosus.
What is Total Anomalous Pulmonary Vein Drainage? Is this compatible with life? Why?
Pulmonary veins drain into a common pulmonary venous chamber and then through a persistent left superior vena cava; No direct venous return to the heart and life is only sustained with an atrial septal defect
WHat is the most common cyanotic congenital heart disease?
Right to Left Shunt
What four anatomic changes define the tetralogy of fallot?
- Pulmonary stenosis
- Ventricular septal defect
- Dextropositition of the aorta so that it overrides the ventricular septal defect
- Right Ventricular Hypertrophy
What morphological structure is protective for a patient with tetralogy of fallot?
Patent ductus arteriosus; Provides source of blood to otherwise depreived pulmonary vascular bed
What is the mechanism of tetralogy of fallot that causes blueberry cyanosis?
Severe pulmonary stenosis forces blood through the ventricular septal defect
What is tricuspid atresia? How is blood delivered to the left side of the heart? How is blood delivered to the right ventricle?
Congential absence of the tricuspid valve and therefore no AV connection in the right heart; Atrial septal defect; Ventricular septal defect
What is a transposition of the great arteries defect? What would allow this defect to be compatible with life?
The aorta is supplied by the right ventricle and the pulmonary trunk is supplied by the left ventricle; VSD, ASD, PDA
What is congenitally corrected transposition of the great arteries? What effect does this have on the patient?
The aorta is to the left of the pulmonary trunk. With only this defect, the patient is functionally normal
What is the Taussig-Bing malformation?
The aorta and the pulmonary trunk arise from the RV + a VSD
What three trisomies are associated with Taussig-Bing malformation?
13, 18, 21
What is coarctation of the aorta and what causes it?
A persistent posterior shelf within the aorta persists causing obstruction of blood flow.
What is the clinical hallmark of coarctation of the aorta? What Syx are seen in the upper part of the body? Lower part of the body?
Discrepancy in blood pressure betwixt the upper and lower extremities; LVH, dizziness, headaches, epistaxis; Weakness, pallor, coldness
Complication of Coarctation of the Aorta?
- Heart failure
- Rupture of a dissecting aneurysm
- infective endarteritis at point of narrowing or at the site of jet-stream impinghement on the wall immediately distal to the coarctation
- Cerebral Hemorrhage
- Stenosis or infective endocarditis of a bicuspid aortic valve
What causes pulmonary stenosis?
- deformities of endocardial cushion region
- abnormality of the right ventricular infundibular muscle
- abnormal development of the more distal parts of the pulmonary artery tree
What are three types of congenital aortic stenosis?
Valvular, subvalvular, supravalvular
What is the clinical progression of valvular aortic stenosis?
- Semilunar valve often formed bicuspid
- Valve thickens and calcifies
- Syx become apparent in adulthood (exertional dyspnea and angia pectoris)
Describe the pathophysiology of a coronary artery arising from a pulmonary artery
The anomalous artery anastamoses with the other coronary artery causing a shunt from the coronary artery to the pulmonary artery (oxygenated to deoxygenated shunt)
What is Ebstein’s Malformation?
Downward displacement of an abnormal tricuspid valve into an underdeveloped right ventricle allow blood regurgitation back in to RA from RV
What type of complications would one expect to find in a patient with Ebstein’s Malformation?
Heart failure, massive right atrial dilation, arrhythmias w/ palpitations, tachycardia, and sudden death
What maternal disease would make an AV heartblock likely occur in a fetus?
Systemic Lupus Erythematous - Maternal SSA/Ro or SSB/La Abs are transmitted to the fetus and cause AV heartblock
A newborn expires and the heart is shown at autopsy. What is this condition generally caused by? What is the prognosis of this condition? What is your Dx?
Underlying CV anomalies that lead to LVH in the face of an inability to meet the increased myocardial oxygen demand such as aortic stenosis and coarctation of the aorta; Bad (transplantation required for survival); Endocardial Fibroelastosis
What is Endocardial fibroelastosis? What is more common, primary or secondary?
Fibroelastotic thickening of the left ventricular endocardium (possibly affecting valves); Secondary, primary rarely seen
What is dextrocardia? When is dextrocardia most severe? When is it viable?
Rightward orientation of the base-apex axis of the heart often associated with a mirror image of the normal left-sided location and configuration; Without reciprocal mirroring of remaining viscera; With situs inversus (vital organ mirroring)
