[Magnesium in cardiology. Fundamentals and potential indications].

The precise mechanism of magnesium effects on the heart is unknown. It may be based on calcium antagonism, prevention of vasospasm, enhancement of metabolic processes or inhibition of platelet aggregation. At present there are no established indications for parenteral magnesium administration. Probatory magnesium treatment can however be used in all tachyarrhythmias without major risk of adverse effects; in polymorphic ventricular tachycardia with QT prolongation (torsade de pointes) it can be recommended as a primary measure. Further investigations are needed to confirm the so far encouraging results of prophylactic intravenous magnesium administration in acute myocardial infarction.