[Physiologic bases for the use of L-carnitine in cardiology]

L-Carnitine can affect cardiac function principally by improving fatty acid and/or glucose metabolism, by increasing perfusion due to modulation of the deformability of erythrocytes and/or vasodilatation, and by stabilising mitochondrial and plasma membranes of cardiomyocytes. While short-term administration of L-carnitine in vivo does not increase the muscular and probably also not the cardiac L-carnitine content, it improves the function of perfused rat or pig hearts in the reperfusion phase after ischemia. Long-term administration of L-carnitine increases the cardiac L-carnitine content in mice and has been shown to improve surrogate markers of coronary heart disease such as arrhythmias, nitrate consumption, and left ventricular dilatation and infarct size in patients after myocardial infarction. The only clear indication for L-carnitine in cardiology is to date cardiomyopathy associated with primary L-carnitine deficiency.