What does a prominent 'v' wave in the right atrial venous waveform indicate?

A Prominent "v" Wave in the Right Atrial Venous Waveform Indicates Tricuspid Valve Regurgitation

A prominent "v" wave in the right atrial venous waveform indicates tricuspid valve regurgitation (option a). This finding is a specific hemodynamic marker of severe tricuspid regurgitation (TR) and represents regurgitant blood flow from the right ventricle into the right atrium during systole.

Hemodynamic Changes in Tricuspid Regurgitation

• In normal individuals, the right atrial pressure waveform shows a normal pattern with an "a" wave (atrial contraction), "c" wave (tricuspid valve closure), "x" descent (atrial relaxation), "v" wave (passive atrial filling during ventricular systole), and "y" descent (passive emptying after tricuspid valve opening) 1
• With tricuspid regurgitation, there is retrograde flow from the right ventricle into the right atrium during systole, causing a prominent "v" wave in the right atrial pressure tracing 1
• The severity of TR correlates with the magnitude of the "v" wave, with severe TR showing the most pronounced "v" waves 2

Diagnostic Features of Severe Tricuspid Regurgitation

• A prominent systolic "v" wave in the right atrial pressure tracing is characteristic of severe tricuspid regurgitation 1
• In severe TR, there can be "ventricularization" of the right atrial pressure tracing, where the RA pressure contour resembles the RV pressure contour but with lower amplitude 1
• Systolic flow reversal in the hepatic veins is another specific marker for severe TR, representing the strongest additional parameter for evaluating TR severity 2
• The CW Doppler envelope of the TR jet may be truncated (notched) with a triangular contour and an early peak velocity, indicating elevated right atrial pressure due to severe TR 2

Differentiating from Other Conditions

• Atrial fibrillation (option b) typically causes loss of the "a" wave in the atrial pressure tracing due to absence of organized atrial contraction, but does not specifically cause prominent "v" waves 2
• Pulmonary embolism (option c) may cause right heart strain but does not directly cause prominent "v" waves unless it leads to secondary tricuspid regurgitation 2
• Atrial septal defect (option d) typically shows volume overload of the right atrium and ventricle but is not characterized by prominent "v" waves in the right atrial pressure tracing 2
• Atrial flutter (option e) affects the electrical activity and may alter the "a" wave pattern but does not specifically cause prominent "v" waves 2

Clinical Implications

• The presence of a prominent "v" wave should prompt evaluation for tricuspid valve dysfunction, particularly regurgitation 3
• While prominent "v" waves are specific for TR, their absence does not rule out moderate or severe TR (sensitivity limitations) 3
• The magnitude of the "v" wave can be influenced by right ventricular preload, afterload, right atrial compliance, and the respiratory cycle 1
• In severe TR with high right atrial pressures, echocardiographic estimation of pulmonary artery pressure may be challenging and often underestimated 4

Additional Findings in Severe TR

• Right atrial and right ventricular dilatation 2
• Dilated and pulsatile inferior vena cava and hepatic veins 2
• Systolic bowing of the interatrial septum toward the left atrium 2
• An end-systolic RV eccentricity index >2 (sensitivity 79%) 2

In conclusion, a prominent "v" wave in the right atrial venous waveform is a characteristic finding of tricuspid valve regurgitation, representing the backflow of blood from the right ventricle into the right atrium during systole.