Sudden Death and the Familial Occurrence of Mid-Systolic Click, Late Systolic Murmur Syndrome

Abstract

The propositus, one of six family members with the ballooning posterior mitral leaflet syndrome, had experienced five syncopal episodes prior to initial presentation with cardiac arrest. Subsequent evaluation, after nearly complete recovery, revealed slight Q-Tc prolongation but no arrhythmia, despite extensive ECG monitoring and maximum exercise testing. Intravenous propranolol failed to alter the Q-Tc interval or the magnitude of ballooning of the posterior mitral leaflet at cardiac catheterization. Therapy with oral Dilantin to the point of clinical toxicity failed to significantly shorten the Q-Tc interval. While on oral propranolol, the patient, during a stressful argument, suffered her final cardiac arrest. Detailed post mortem studies were performed, with histochemical identification of the "myxomatous" material not previously reported.

Angiotensin II Type 1 Receptor Gene Adenine/Cytosine1166 Polymorphism is not Associated With Mitral Valve Prolapse Syndrome in Taiwan Chinese

“…Although most cases appear to be sporadic, echocardiographic screening of families for MVP has suggested autosomal dominant inheritance of the trait with an age-and sex-dependent expression, [23][24][25] and identification of the locus for antosomal dominant myomatous MVP to chromosome 16p11.2-p12.1 has been reported. 26 In addition, X-linked inheritance has been reported in a special form of MVP, called myxomatous valvular dystrophy, which has been mapped to Xq28.…”

The Polymorphisms of Codon 727 and 52 of Thyroid-Stimulating Hormone Receptor Gene are not Associated with Mitral Valve Prolapse Syndrome in Taiwan Chinese.

“…Although most cases appear to be sporadic, echocardiographic screening of families for MVP has suggested autosomal dominant inheritance of the trait with an age and sex dependent expression. [23][24][25] Identification of the locus for autosomal dominant myomatous MVP to chromosome 16p11.2-p12.1 was reported. 26) In addition, X-linked inheritance has been reported in a special form of MVP, called myxomatous valvular dystrophy, which has been mapped to Xq28.…”

Sudden death associated with myxomatous transformation of the mitral valve in an 8-year-old boy

“…Malignant ventricular arrhythmias have clinically been detected before the fatal event [17], leading to ventricular fibrillation in most cases [12]. A possible autosomal dominant pattern of inheritance is meanwhile generally accepted [3,13]. However, discussion still continues concerning the aetiology and pathogenesis of the condition.…”