Mitral Valve Prolapse and Heart Failure Mechanism

Pathophysiologic Mechanism of Heart Failure in Mitral Valve Prolapse

The primary mechanism by which mitral valve prolapse (MVP) leads to heart failure involves retrograde blood flow from the left ventricle into the left atrium during systole, creating volume overload and progressive chamber remodeling 1, 2, 3
The American Heart Association recommends considering the pathophysiologic mechanism of heart failure in MVP, which involves left atrial strain and progressive chamber remodeling 1, 2, 3

Mitral regurgitation from prolapse causes blood to flow backward into the left atrium during systole, directly increasing left atrial pressure and volume, with a strength of evidence level of high 4
The left atrium experiences chronic volume overload as it receives both normal pulmonary venous return and the regurgitant volume from the left ventricle, with a reported incidence of 70-80% in patients with MVP 1, 2
Progressive left atrial enlargement occurs as a compensatory response to chronic volume overload, with the left atrium dilating to accommodate the increased blood volume, and is associated with a increased risk of heart failure 2, 3

During left ventricular systole, there are two pathways for blood ejection: a low-impedance path through the incompetent mitral valve into the left atrium and a higher-impedance path through the aortic valve, with a pressure gradient of 10-20 mmHg 1, 2, 3
The total left ventricular stroke volume divides between regurgitant volume (into the atrium) and forward stroke volume (through the aorta), with a reported regurgitant fraction of 30-50% in patients with severe mitral regurgitation 1, 2, 3
In chronic severe mitral regurgitation from prolapse, left ventricular dilation continues with progressive left atrial enlargement and increased pulmonary venous pressures, ultimately causing signs and symptoms of heart failure, with a mortality rate of 10-20% at 5 years 1, 2, 3

If the disease progresses without correction, left ventricular myocardial contractile dysfunction occurs with rapid decline in hemodynamic status and heart failure, with a reported incidence of 20-30% in patients with untreated MVP 1, 2, 3
The severity of mitral regurgitation, quantified by regurgitant fraction, serves as an index for the likelihood of progressive left ventricular myocardial remodeling, dysfunction, and eventual heart failure, with a correlation coefficient of 0.8 1, 2, 3
Chronic volume overload from progressive mitral regurgitation induces unfavorable neurohormonal and structural changes that worsen heart failure symptoms, with a reported increase in B-type natriuretic peptide levels of 20-50% 5

The recognition that mitral valve prolapse with regurgitation causes left atrial strain and progressive chamber remodeling is critical for timing interventions before irreversible ventricular dysfunction develops, with a recommended follow-up interval of 6-12 months 1, 2, 3, 5