Left ventricular function in mitral valve prolapse: assessment with radionuclide cineangiography

Area of Science:

• Cardiology
• Cardiovascular Physiology

Background:

• Abnormalities in left ventricular contraction in mitral valve prolapse (MVP) suggest a potential myocardial component.
• Assessing systolic left ventricular function is crucial for understanding MVP pathophysiology.

Purpose of the Study:

• To evaluate systolic left ventricular function in patients diagnosed with mitral valve prolapse.
• To identify potential myocardial factors contributing to MVP.

Main Methods:

• Technetium-99m gated equilibrium radionuclide cineangiography was employed.
• 47 patients with mitral valve prolapse were studied, divided into groups with and without mitral regurgitation.
• Left ventricular ejection fraction was measured at rest and during maximal exercise.

Main Results:

• Patients without mitral regurgitation had normal resting ejection fraction but reduced ejection fraction during exercise compared to controls (64% vs 71%, p < 0.005).
• Patients with mitral regurgitation showed normal resting ejection fraction, but diminished function with exercise.
• No independent association was found between chest pain, arrhythmia, or echocardiographic findings and impaired ventricular reserve.

Conclusions:

• Many mitral valve prolapse patients exhibit normal left ventricular function.
• A subset of patients without mitral regurgitation demonstrates impaired left ventricular functional reserve during exercise.
• This diminished reserve suggests a possible underlying cardiomyopathic process in specific MVP patients.