Cardiology · Valvular Heart Disease
The facts most likely to be tested
Tricuspid regurgitation presents as a holosystolic murmur heard best at the left lower sternal border that increases in intensity with inspiration.
The most common cause of secondary tricuspid regurgitation is pulmonary hypertension leading to right ventricular dilation and annular stretching.
Physical examination findings include a prominent v-wave in the jugular venous pulsation and a pulsatile liver due to retrograde venous flow.
Primary tricuspid regurgitation is frequently associated with infective endocarditis in patients with a history of intravenous drug use.
The Carvallo sign is the pathognomonic increase in the intensity of the tricuspid regurgitation murmur during inspiration due to increased venous return to the right heart.
Echocardiography is the diagnostic test of choice to assess the severity of regurgitation, right ventricular size, and pulmonary artery systolic pressure.
Surgical intervention, typically tricuspid valve repair or replacement, is indicated for severe symptomatic tricuspid regurgitation or when there is progressive right ventricular dysfunction.
Vignette unlocked
A 34-year-old male with a history of intravenous drug use presents to the clinic with progressive fatigue and abdominal swelling. Physical examination reveals a holosystolic murmur at the left lower sternal border that increases in intensity with inspiration. The patient has jugular venous distension with a prominent v-wave and a pulsatile liver on abdominal palpation. A transthoracic echocardiogram confirms severe valvular regurgitation and vegetation on the tricuspid valve leaflets.
What is the most likely mechanism for the increase in murmur intensity during inspiration?
Increased venous return to the right heart
The vignette tests the Carvallo sign, where inspiration increases venous return to the right ventricle, thereby increasing the volume of blood regurgitated across the incompetent tricuspid valve.
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Etiology / Epidemiology
Most commonly caused by pulmonary hypertension or left-sided heart failure leading to annular dilation.
Clinical Manifestations
Holosystolic murmur at the left sternal border that increases with Carvallo's sign (inspiration).
Diagnosis
Transthoracic echocardiogram is the gold standard to assess valve morphology and regurgitant severity.
Treatment
Treat underlying cause; diuretics for volume overload; surgery if severe and symptomatic.
Prognosis
Severe TR leads to right-sided heart failure and systemic venous congestion.
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Epidemiology & Etiology
Primary TR is rare, often due to rheumatic heart disease, Ebstein anomaly, or endocarditis. Secondary (functional) TR is far more common, resulting from RV dilation due to pulmonary hypertension or left-sided valvular disease. IV drug users are at high risk for staphylococcal endocarditis affecting the tricuspid valve.
Pertinent Anatomy
The tricuspid valve consists of three leaflets located between the right atrium and right ventricle. Dilation of the tricuspid annulus prevents proper leaflet coaptation, leading to regurgitation. The valve is highly sensitive to changes in right ventricular pressure and volume.
Pathophysiology
Regurgitation causes volume overload in the right atrium and ventricle, leading to atrial fibrillation and eventual right-sided heart failure. Increased right atrial pressure is transmitted to the venous system, causing hepatic congestion and peripheral edema. Chronic volume overload results in RV remodeling and decreased cardiac output.
Clinical Manifestations
Patients present with peripheral edema, ascites, and fatigue. The classic murmur is a holosystolic, blowing murmur heard best at the left sternal border, which intensifies with Carvallo's sign. Physical exam reveals a pulsatile liver and prominent v-waves in the jugular venous pulse. Signs of severe right heart failure include jaundice and cardiac cirrhosis.
Diagnosis
Transthoracic echocardiogram is the diagnostic test of choice to visualize valve anatomy and quantify regurgitation. Doppler flow studies confirm the direction and velocity of the regurgitant jet. Cardiac MRI is reserved for cases where echo is non-diagnostic for RV size and function.
Treatment
Management focuses on treating the underlying cause, such as pulmonary hypertension. Loop diuretics are the first-line therapy for symptomatic volume overload. Avoid diuretics if the patient is preload-dependent. Surgical tricuspid valve repair (annuloplasty) is indicated for severe symptomatic TR or during left-sided valve surgery.
Prognosis
Severe, untreated TR leads to cardiac cirrhosis and refractory right-sided heart failure. Patients require serial echocardiograms to monitor RV size and function to prevent irreversible myocardial damage.
Differential Diagnosis
Mitral Regurgitation: Murmur does not increase with inspiration
VSD: Harsh, holosystolic murmur with a palpable thrill
Constrictive Pericarditis: Kussmaul sign present without a holosystolic murmur
Right Ventricular Infarction: Hypotension and clear lungs
Ebstein Anomaly: Associated with maternal lithium use