The myocardial distribution and plasma concentration of carnitine in patients with mitral valve disease.

The myocardial distribution and concentration of carnitine and its fractions was studied in 11 patients with mitral valve disease not associated with congestive heart failure (CHF). The plasma concentration of carnitine was found to be identical to the normal values documented in the literature. The left ventricular papillary muscle had the highest concentrations of total, short-acyl, long-acyl, and free carnitine, being significantly higher than those of the right ventricle, while the right atrial appendage had the lowest values of all fractions of carnitine. The proportion of long-acyl carnitine to total carnitine was significantly greater in the left ventricle than in either the right atrium or the atrial septum, and other carnitine fractions were identical in all cardiac chambers. Our results suggest that in the compensated heart with mitral valve disease, carnitine and its fractions are greatest in the left ventricle in the muscles of all cardiac chambers, and that long-acyl carnitine is most likely to be linked to the cardiac muscle demanding a higher cardiac performance.