High doses of L-carnitine in acute myocardial infarction: metabolic and antiarrhythmic effects

Abstract

Fatty acids accumulate in the muscle cells in some carnitine deficiency syndromes due to a variety of genetic defects in intermediary metabolism. L-Carnitine administration may relieve this excess by transporting acyl compounds out of the cell as acylcarnitine. Similar fatty acid accumulation occurs during myocardial ischaemia because of the decreased rate of beta-oxidation, and this has been put forward as a cause of ventricular arrhythmias. This study was carried out to investigate whether administration of high doses of i.v. L-carnitine in patients with acute myocardial infarction could increase urinary excretion of acylcarnitine and reduce early ventricular arrhythmias. Fifty-six patients suffering from acute myocardial infarction, admitted to the Coronary Unit between 3 and 12 h after the onset of symptoms, were included in the study. The design of the study was double blind, parallel and placebo controlled. Allocation of treatment to patients was done randomly after stratification (time from onset of pain and site of infarction). The first group (28 patients) received intravenous L-carnitine at a dose of 100 mg kg-1 b.w. every 12 h for 36 h while the second group (28 patients) received placebo intravenously. Immediately before starting treatment two blood samples were taken (at 5-min intervals) and a further 16 samples were taken at regular intervals over the following 48 h. Patients' urine was collected over the same period of time. Concentrations of free carnitine, short chain acylcarnitine esters and long chain acylcarnitine esters in serum and urine were measured.(ABSTRACT TRUNCATED AT 250 WORDS)

Arrhythmias and Conduction Defects as Presenting Symptoms of Fatty Acid Oxidation Disorders in Children

“…Some have proposed using it to prevent arrhythmias in acute myocardial infarction. 27 Along the same line, free polyunsaturated fatty acids have a protective effect on ischemia-induced ventricular fibrillation by inhibiting the electrical automaticity/excitability of the cardiac myocyte. 28 The inhibition of CPT-I prevents the accumulation of long-chain acylcarnitines in the sarcolemma and, as a consequence, the incidence of lethal arrhythmias induced by ischemia in the rat heart.…”

Endothelium-dependent vasorelaxation induced by L-carnitine in isolated aorta from normotensive and hypertensive rats

“…Carnitine has useful properties in some cardiovascular pathologies such as heart failure (Mancini et al 1992 ;Sethi et al 1999), angina pectoris (Bartels et al 1994 ;Mondillo et al 1995) and arrhythmias (Rizzon et al 1989). In the same way, lcarnitine has been shown to be useful in patients with essential hypertension and diabetes (Digiesi et al 1989), because it was able to improve the left ventricle function and to induce lowering of some fractions of serum lipids (Digiesi et al 1994).…”

Metabolic Modulators to Treat Cardiac Arrhythmias Induced by Ischemia and Reperfusion

“…Although the studied groups of patients were small, L-Car administration to patients with ischemic heart disease appears to be a promising therapy of ischemia-induced arrhythmia as potentially addressed to restoring of membrane rest-potential (Rizzon et al, 1989). Cardiac electrophysiology after L-Car administration (30 mg/kg over 3 min) did not show any changes either in the conductivity time or in refraction period.…”