Review Question - QID 100658

This patient is an IV drug user who presents with infective endocarditis of his tricuspid valve. This may present with tricuspid regurgitation (TR) as a result of valvular insufficiency.

Although the mitral valve is most commonly affected in endocarditis in the general population, in IV drug users the tricuspid valve is most commonly affected. TR is best heard at the left lower sternal border. It increases with inspiration because of an increase in right atrial return. Other physical findings can include RV lift, ascites, and peripheral edema. Aside from endocarditis, TR can also occur because of myocardial infarction, pulmonary hypertension leading to right heart failure, Ebstein's anomaly, rheumatic heart disease, blunt trauma, and pacemaker wires.

Pierce et al. review the diagnosis and treatment of infectious endocarditis. Aside from IV drug use, other risk factors include a prosthetic valve and structural or congenital heart disease. Understanding the etiology of the infection is important as it inform antibiotic choice based on the likely microorganism. However, blood cultures are always necessary and should be taken prior to the initiation of IV antibiotics.

Solinas et al. note that for patients with severe tricuspid regurgitation, either as a sequelae of infectious endocarditis or other causes, patching the anterior leaflet of the valve is one approach to surgical treatment. This patch is combined with an annuloplasty, which can result in improved leaflet coaptation.

Illustration A displays an echocardiogram showing a vegetation (at the arrow head) on the tricuspid valve.

Illustration V demonstrates the typical heart sounds found with tricuspid regurgitation.

Incorrect answers:
Answer 1: VSD, the most common congenital heart defect, does present with a holosystolic murmur, but the murmur does not increase upon inspiration. Small defects lead to a harsh murmur while larger ones have a soft quality.
Answer 3: MR also presents with a holosystolic murmur that does not increase upon inspiration. It is heard best at the apex, radiates to the axilla and increases with a squat or hand grip as well as with expiration.
Answer 4: Aortic stenosis leads to another systolic murmur, but is not holosystolic. Instead, it causes a harsh late-peaking crescendo-decrescendo systolic murmur that radiates to the carotids.
Answer 5: Pulmonary stenosis leads to a systolic murmur that does increase with inspiration. However, the murmur is not holosystolic, bu rather, has a harsh crescendo-decrescendo quality.