Can tricuspid regurgitation cause a murmur?

Yes, Tricuspid Regurgitation Causes a Murmur

Tricuspid regurgitation definitively produces a systolic murmur, typically heard at the lower left sternal border, though the characteristics vary based on severity and hemodynamic conditions. 1

Murmur Characteristics

The murmur of TR presents in several distinct patterns depending on the underlying pathophysiology:

Holosystolic (Pansystolic) Murmur

• Most common presentation in moderate to severe TR with pulmonary hypertension
• Heard throughout systole at the lower left parasternal region
• Results from continuous pressure gradient between right ventricle and right atrium throughout systole 1

Early Systolic Murmur

• Characteristic of TR without pulmonary hypertension
• Begins with S1 and ends in midsystole
• Occurs because the pressure gradient between RV and RA equalizes earlier in systole when pulmonary pressures are normal 2, 3, 2

Midsystolic Murmur

• Less frequently, functional TR can produce a midsystolic (crescendo-decrescendo) murmur
• More common with mild regurgitation 2, 3

Key Diagnostic Features

Carvallo's Sign (Respiratory Variation)

• The murmur increases in intensity with inspiration - this is pathognomonic for right-sided valve lesions
• Inspiration increases venous return to the right heart, augmenting the regurgitant volume and murmur intensity
• Present in most cases but absence does not exclude TR 1, 4

Associated Physical Findings

• Prominent systolic c and v waves in jugular venous pulse
• Systolic hepatic pulsation
• In severe cases: venous systolic thrill and murmur at the base of the neck 1, 5
• Pulsatile varicose veins or systolic propulsion of eyeballs (rare) 1

Critical Clinical Pitfall: Silent Severe TR

Up to 24% of patients with severe TR proven by ventriculography have NO audible murmur 6. This occurs when:

• Regurgitant flow is laminar rather than turbulent
• Peak velocities are low (1.1-1.9 m/sec vs 1.7-5.1 m/sec in audible TR)
• Characterized by "candle flame pattern" on color Doppler 6

Therefore, absence of a murmur does NOT exclude significant TR - echocardiography is essential when TR is suspected clinically based on:

• Elevated jugular venous pressure with prominent v waves
• Hepatomegaly with systolic pulsation
• Right ventricular enlargement on imaging
• Unexplained right heart failure 1

Severity Assessment Beyond the Murmur

The murmur alone is unreliable for grading severity:

• Severe TR may have minimal or no murmur if flow is laminar 6
• Moderate TR with turbulent flow may have a loud murmur
• Additional maneuvers help: hepatic pressure maneuver (manual pressure below liver) can enhance the murmur 7

Doppler echocardiography is mandatory for accurate severity assessment, as it detects clinically silent TR and quantifies regurgitant volume, vena contracta, and estimates pulmonary artery pressures 1

Practical Algorithm for Suspected TR

1. Listen at lower left sternal border during inspiration - if murmur increases, TR is likely
2. Examine jugular veins - look for prominent systolic waves
3. Palpate liver - assess for systolic pulsation
4. If ANY of these are present OR patient has risk factors (AF, RV dysfunction, pulmonary hypertension, pacemaker leads, left-sided valve disease):
   • Order comprehensive echocardiography with Doppler 1, 8
5. Do not rely on murmur absence to exclude TR - proceed with imaging if clinical suspicion exists 6

The murmur characteristics combined with respiratory variation and associated right heart findings provide the clinical diagnosis, but echocardiography remains the definitive diagnostic tool for TR assessment 1.