[Role of magnesium in cardiac metabolism]

Numerous studies have suggested that magnesium ion (Mg(2+)) plays an important role in pathogenesis of cardiovascular diseases including hypertension, ischemic heart disease. Hypomagnesemia is often associated with the imbalance of sodium, potassium, and calcium ions. Magnesium deficiency can occur frequently in alcoholics, and in patients with hypertension, congestive heart failure, myocardial infarction. Magnesium deficiency induces an increase in intracellular Ca(2+) concentration in cardiac myocytes, formation of reactive oxygen species, production of inflammatory cytokines, leading to the development of ischemic heart disease, congestive heart disease, sudden cardiac death, atherosclerosis, and arrhythmia. In addition, catecholamines can evoke marked Mg(2+)efflux which is associated with a concomitant increase in the force of contraction of the heart. While many of the mechanisms remains elusive, the beneficial effects of magnesium on the myocardium appear to be convincing. Further studies will be necessary to elucidate the molecular basis of the cardio-protective effects of magnesium.