Carnitine supplementation improves cardiac strain rate in children on chronic hemodialysis

Abstract

Carnitine plays a key role in energy production in the myocardium. Carnitine deficiency commonly occurs in patients on chronic hemodialysis (HD) and may contribute to cardiomyopathy. Carnitine levels and cardiac function of nine children on HD were assessed before and after 6 months of intravenous levocarnitine supplementation. Standard echocardiographic (ECHO) measures of left ventricular (LV) function as well as strain and strain rate analysis using novel speckle-tracking echocardiography were performed and the results compared to those of a control group of children on chronic HD. Following carnitine supplementation, total (49.0 ± 1.67 vs. 298.0 ± 31.8 μmol/L) and free carnitine (29.0 ± 1.20 vs. 180.4 ± 19.2 μmol/L) increased (p < 0.0001), and the acyl:free (A:F) carnitine ratio improved (0.73 ± 0.04 vs. 0.65 ± 0.05; p = 0.02). There were no changes in standard ECHO measures of LV function, including end diastolic dimension, mass index, ejection fraction, and fractional shortening. There was significant (p = 0.017) improvement in the longitudinal strain rate (-1.48 ± 0.11 vs -1.91 ± 0.12) after carnitine supplementation in the study group. No improvements in LV function, strain, or strain rate occurred in controls. Levocarnitine supplementation improved carnitine levels, the A:F ratio, and longitudinal strain rate in children on HD.