CLINICAL SYMPTOMS OF MITRAL-VALVE PROLAPSE ARE RELATED TO HYPOMAGNESEMIA AND ATTENUATED BY MAGNESIUM SUPPLEMENTATION

Mitral valve prolapse syndrome (MVP) is a frequent disorder characteri zed by a number of complaints which lessen the quality of life. The pa thogenesis of MVP symptoms has not been fully elucidated. Hyperadrener gic activity and magnesium deficiency have been suggested. This study was designed to verify the concept that heavily symptomatic MVP is acc ompanied by hypomagnesemia and to elucidate whether magnesium suppleme ntation alleviates the symptoms and influences adrenergic activity. We assessed serum magnesium in 141 subjects with heavily symptomatic pri mary MVP and in 40 healthy controls. Decreased serum magnesium was fou nd in 60% of patients and in 5% of controls (p <0.0001). Patients with low serum magnesium were subjected to magnesium or placebo supplement ation in a double-blind, crossover fashion. Typical symptoms of MVP (n = 13), intensity of anxiety, and daily excretion of catecholamines we re determined. After 5 weeks, the mean number of symptoms per patient decreased from 10.4 +/- 2.1 to 5.6 +/- 2.5 (p <0.0001), and a signific ant reduction in weakness, chest pain, dyspnea, palpitations, and anxi ety was observed. increased noradrenaline excretion before and after m agnesium was seen in 63% and 17% of patients, respectively (p <0.01). Mean daily excretion of noradrenaline and adrenaline was significantly diminished after magnesium. It is concluded that many patients with h eavily symptomatic MVP have low serum magnesium, and supplementation o f this ion leads to improvement in most symptoms along with a decrease in catecholamine excretion. (C) 1997 by Excerpta Medica, Inc.