Congenital Heart Diseases Flashcards
Normal formation of heart loop diagram
Atrial septal formation diagram
Developmental atrial flap valve
Interventricular foramen
Remains open until 7th week gestation when the membranous septum forms
Papillary muscle and cordae tendinae development
Fetal circulation
Why are most congenital heart defects unnoticed until birth?
Because most of them are bypassed by fetal circulation
Cyanotic vs acyanotic
Causing cyanosis vs not
ie
Shunting past lung vs not
ie
Right-to-left shunt vs left-to-right shunt
Left-to-right shunt reversal
Elevated pulmonary resistance due to an early life left-to-right shunt may result in a change in shunt direction, accompanied by cyanosis and hypoxemia.
Aside from pathology resulting from their anatomy, patients with congenital heart disease are susecptible to ___.
Aside from pathology resulting from their anatomy, patients with congenital heart disease are susecptible to bacterial endocarditis
Atrial septal defect
Most common atrial septal defect
Ostium secundum defect
Ostium primum defect
Failure of the septum primum to fuse with the endocardial cushions, resulting in atrial sepatl defect.
Sinus venosus defect
Loss of the roof of the right atrium due to improper development of the pulmonary veins, resulting in a right atrium -> pulmonary vein -> left atrium shunt.
Patent foramen ovale
In ~20% of the general population, but doesn’t functionally matter as long as the LA pressure is greater than the RA pressure. However, if there is, for example, increase in right heart afterload resulting in backward increase in RA pressure, the patent foramen ovale may reopen. This results in a right->left cyanotic shunt
Paradoxical embolism
When a thrombus in the venous system and shoots to the RA, through the foramen ovale, and into systemic arterial circulation.
___ also helps drive right-to-left atrial shunts.
High right ventricular compliance also helps drive right-to-left atrial shunts.
Right ventricular compliance increases after birth due to regression of the RV.
Atrial septal defect physical exam
- S2 splitting
- Systolic murmur (pansystolic)
- Mid-diastolic murmur may be present (due to increased tricuspid valve flow)
- Blood traversing the ASD itself does not produce a murmur because of the absence of a pressure gradient between the two atria
Treatment for ASDs
Most people are asymptomatic, but for those who are symptomatic, elective surgery is recommended to prevent heart failure.
Ventricular septal defect
Ventricular septal defects often result in ___ which mediates the chronic disease pathology.
Ventricular septal defects often result in eccentric hypertrophy of the left ventricle which mediates the chronic disease pathology.
Ventricular septal defects on physical exam
- Harsh holosystolic murmur
- Palpable systolic thrill over left sternal border
- Mid-disatolic rumble over apex due to increased flow through mitral valve
- If there is shunt reversal due to pulmonary vascular disease, a loud P2 and cyanosis may be appreciated
Treatment of ventricular septal defects
- By 2 years of age, 50% of small to midsized VSDs will spontaneously close or close to the point that they are asymptomatic
- Surgical correction recommended for extreme cases (congestive heart failure or pulmonary vascular disease) and for those that fail to close after ~2 years
Patent ductus arteriosus
Patent ductus arteriosus on physical exam
- Continuous, machine-like murmur (pressure gradient exists between the aorta and pulmonary artery in both systole and diastole)
- Best heard in the left subclavicular region
- If there is shunt reversal, cyanosis and clubbing may be present
Congenital aortic stenosis
Congenital pulmonic stenosis
Coarctation of the aorta
Tetralogy of Fallot
Transposition
Eisenmenger Syndrome
The left-to-right -> right-to-left shunt shift
- Thrombosis within the pulmonary vessels is a major mechanism increasing the pulmonary resistance
- Patients are cyanotic with digital clubbing
- Prominent a wave on JVP, reflecting elevated RA pressure
Transposition is treated with. . .
. . . emergency surgery to create an atrial septal defect.
This allows for mixing of the parallel circuits of blood and allows the oxygen saturation to improve enough to get to surgical repair.
In utero, the fetus is kept alive through flow through the ductus arteriosus and foramen ovale.
An infant is cyanotic at birth. A chest x-ray is taken. What is the likely diagnosis?
Transposition
You can tell from the ‘box-like’ mediastinum, which is due to the lack of proper conotruncal twist
The only oxygenated coronary bloodflow from a transposition heart comes from ___.
The only oxygenated coronary bloodflow from a transposition heart comes from the associated atrial septal defect.
Atrial septostomy
Surgical foration of an atrial septal hole. Can be done in the cath lab in emergency situations, like cyanosis from transposition without availability of PGE1 or a surgeon available for immediate open heart surgery.
An infant has low oxygen saturation, decreasing even lower with crying. A chest X-ray is taken. What is the likely diagnosis?
Tetralogy of fallot
This is a tough one. The main findings are 1. a right-sided aortic arch and 2. substantially decreased pulmonary vascular markings.
The right sided arch is actually fairly common with multiple conotruncal defects, but the vascular markings are telling. There is not much pulmonary bloodflow due to high pulmonary resistance, hence the decreased markings.
