Mitral valve prolapse without significant mitral regurgitation is usually asymptomatic but may be associated with a syndrome of nonspecific chest pain, dyspnea, fatigue, or palpitations. Most patients are young, female, thin, and some have skeletal deformities, such as pectus excavatum or scoliosis. On auscultation, there are characteristic mid-systolic clicks that may be multiple and emanate from the chordae or redundant valve tissue. If leaflets fail to come together properly, the clicks will be followed by a late systolic murmur. As the mitral regurgitation worsens, the murmur is heard more and more throughout systole. The smaller the LV chamber, the greater the degree of leaflet prolapse, and thus auscultatory findings are often accentuated in the standing position or during the Valsalva maneuver. Whether sudden cardiac death presumably due to ventricular arrhythmias is more frequent in patients with mitral valve prolapse remains controversial. Mitral prolapse progresses to significant mitral regurgitation over 3–16 years in about one-fourth of individuals.
The diagnosis is primarily clinical and confirmed echocardiographically. Mitral prolapse is often associated with aortic root disease, and any evidence for a dilated aorta by chest radiography should prompt either CT or MRI angiography. If palpitations are an issue, an ambulatory monitor is often helpful to distinguish atrial from ventricular tachyarrhythmias.