A 18-year-old IV drug user presents with fever. He has a new murmur and lesions on his fingers (as shown). What is most likely responsible?
Staphylococcus aureus; the patient has splinter hemorrhages
Is Staphylococcus aureus bacterial endocarditis rapid or insidious in onset?
Rapid; it has a high virulence and results in large vegetations on previously normal valves
What is the most common cause of early cyanotic heart disease?
Tetralogy of Fallot
Do right-to-left shunts cause early or late cyanosis?
Early; much of the circulation bypasses the lungs and is not oxygenated
Do left-to-right shunts cause early or late cyanosis?
Late; cyanosis does not occur until the effects of increased pulmonary pressure become significant
A patent ductus arteriosus can be closed by using what drug?
Indomethacin, although surgery is sometimes required as well
What is the order of frequency for the three most common causes of left-to-right shunts?
Ventricular septal defects, atrial septal defects, patent ductus arteriosus
What is Eisenmengers syndrome?
In Eisenmengers syndrome, a left-to-right shunt overloads the pulmonary circulation and causes increasing pulmonary pressures. When pulmonary pressures equal systemic pressures, the shunt switches to right-to-left and cyanosis ensues
The 5 Ts of right-to-left (cyanotic) shunts in congenital heart disease are comprised of which diseases?
Tetralogy of Fallot, Transposition of the great arteries, Truncus arteriosus, Tricuspid atresia, and TAPVR (total anomalous pulmonary venous return)
What are the heart sounds associated with atrial septal defect?
A loud S1 and a wide, fixed split S2
What is persistent truncus arteriosus?
Failure of the aorticopulmonary septum to divide the embryonic truncus arteriosus into the pulmonary trunk and the aorta
What is tricuspid atresia?
Absence of the tricuspid valve and a hypoplastic right ventricle
How do neonates with tricuspid atresia remain viable given their severely compromised circulation?
In order to maintain viability, both an atrial septal defect and a ventricular septal defect are required for babies with tricuspid atresia
What is total anomalous pulmonary venous return?
A disorder in which the pulmonary veins drain into right heart circulation (ie, the superior vena cava or carotid sinus) as opposed to the left atrium
How can an uncorrected ventricular septal defect, atrial septal defect, or patent ductus arteriosus result in progressive pulmonary hypertension?
They can cause compensatory vascular hypertrophy, which results in progressive pulmonary hypertension
Which congenital heart diseases can eventually result in Eisenmengers syndrome?
Uncorrected atrial septal defect, ventricular septal defect, or patent ductus arteriosus
What are two physical findings associated with Eisenmengers syndrome?
Clubbing and polycythemia; both are due to hypoxia secondary to right-to-left shunting
In which direction is blood shunted in Eisenmengers syndrome? How does the condition change over time?
As pulmonary hypertension increases, the original left-to-right shunt reverses into a right-to-left shunt
Tetralogy of Fallot is caused by the displacement of what structure during embryogenesis?
The infundibular septum; it is displaced anteriorly and superiorly
Name the four clinical features of tetralogy of Fallot.
Pulmonary stenosis, Right ventricular hypertrophy, Overriding aorta, and Ventricular septal defect (remember: PROVe)
In patients with tetralogy of Fallot, the severity of which heart lesion determines the patients prognosis?
In tetralogy of Fallot, why does right-to-left shunting occur?
Because the increased pressure in the right ventricle (caused by the stenotic pulmonic valve) causes the blood to be shunted through the path of least resistance (ie, to the left ventricle through the ventricular septal defect)
How does squatting help patients with tetralogy of Fallot improve their symptoms?
Squatting compresses femoral arteries, which causes increased arterial pressure, which in turn reduces right-to-left shunting and causes more blood from the right ventricle to enter the pulmonary circulation
What is the chest x-ray finding that is associated with tetralogy of Fallot?
A boot-shaped heart, which is due to right ventricular hypertrophy
What is the prognosis for infants with D-transposition of great vessels?
They die within the first few months of life if their condition is not surgically corrected by adding a shunt
What is D-transposition of great vessels?
A congenital heart disease characterized by an aorta that leaves the right ventricle (anteriorly) and a pulmonary artery that leaves the left ventricle (posteriorly), causing separation of pulmonary and systemic circulations
What condition must be present for a fetus with D-transposition of great vessels to remain viable?
The presence of a shunt to allow adequate mixing of pulmonary and systemic blood (ie, a ventricular septal defect, atrial septal defect, or patent foramen ovale)
In terms of embryology, what is the cause of D-transposition of great vessels?
Failure of the embryonic aorticopulmonary septum to spiral
What cardiac valvular disease can result from coarctation of the aorta?
What is the difference between infantile and adult types of coarctation of the aorta?
Infantile type occurs when the aortic stenosis is proximal to the insertion of the ductus arteriosus (preductal), and adult type occurs when the aortic stenosis is distal to the ductus arteriosus (postductal) (remember: INfantile IN close to the heart and ADult type Distal to the Ductus)