Right Heart Hemodynamic Findings in Severe Mitral Regurgitation
Elevated pulmonary artery systolic pressure >50 mmHg with no other cause is a key right heart hemodynamic finding that supports the diagnosis of severe mitral regurgitation. 1
Key Right Heart Hemodynamic Parameters
Pulmonary Pressures
- Elevated mean pulmonary artery pressure (PAP) at rest (≥22 mmHg) 2
- Pulmonary artery systolic pressure >50 mmHg without other causes 1
- Significant increase in pulmonary pressures with exercise (systolic PAP >60 mmHg) 2
- Pulmonary hypertension that improves after mitral valve intervention 3
Pulmonary Capillary Wedge Pressure (PCWP)
- Elevated PCWP at rest (≥14 mmHg) in symptomatic patients 2
- Marked increase in PCWP with exercise (≥30 mmHg) 2
- V waves in the PCWP tracing, especially in acute severe MR
Right Ventricular Function
- Right ventricular dysfunction in advanced cases, particularly when mean PAP is significantly elevated 2
- Inverse correlation between mean PAP and right ventricular ejection fraction in symptomatic patients 2
Distinguishing Acute vs. Chronic Severe MR
Acute Severe MR
- Rapid rise in left atrial pressure transmitted to pulmonary circulation 1
- Normal or only mildly increased left atrial and ventricular dimensions 1
- More pronounced V waves in PCWP tracing
- Higher pulmonary pressures relative to chamber size
Chronic Severe MR
- Moderate to severe left atrial enlargement 1
- Left ventricular enlargement 1
- More gradual rise in pulmonary pressures
- Right ventricular adaptation may be present
Hemodynamic Changes During Interventions
- Significant reduction in MR severity may be observed during sedation for TEE due to altered loading conditions 1
- Positive pressure ventilation can significantly reduce the severity of MR assessment 1
- Exercise testing may reveal higher MR burden in apparently asymptomatic patients 2
Common Pitfalls in Hemodynamic Assessment
- Underestimating MR severity due to high left atrial pressures 1
- Failing to account for loading conditions when assessing MR severity 1
- Not considering that even modest MR that develops acutely into a small non-compliant left atrium may cause severe pulmonary congestion 1
- Overlooking that manipulation of circulation and positive pressure ventilation may significantly alter hemodynamics 1
Integrating Hemodynamic Data with Other Findings
When right heart hemodynamic findings suggest severe MR, correlation with echocardiographic parameters is essential:
- Vena contracta width ≥7 mm 1
- Effective regurgitant orifice area (EROA) ≥0.4 cm² for primary MR 1
- Regurgitant volume ≥60 mL 1
- Regurgitant fraction ≥50% 1
- Dense triangular CW Doppler profile 1
- Systolic pulmonary vein flow reversal 1
Remember that right heart catheterization provides valuable complementary information when echocardiographic findings are inconclusive or discordant with clinical presentation 1.