Here is an interesting case report in the green journal in which a patient presenting in cardiac arrest was found to have mitral valve prolapse (with a flail leaflet) and a markedly prolonged QT. Genetic analysis revealed a novel repolarization prolonging sodium channel mutation as well as a desmoplakin gene mutation of uncertain significance. Of interest, this latter mutation is one of the ones associated with arrhythmogenic right ventricular cardiomyopathy.
During the surge of interest in MVPduring the 1980s there was a belief that it was associated with sudden cardiac death but the mechanism was unclear and the purported association has since been disputed. There has also long been suspected an association between MVP and long QT.