Intravenous dl-carnitine fails to increase the double-product during atrial pacing in patients with effort angina. A double-blind randomized study

Infusions of DL-carnitine are reported to improve the tolerance to atrial pacing of patients with angina pectoris. In the present study, six patients with angina of effort and triple vessel disease received two placebo and two carnitine infusions administered in a double-blind randomized fashion. Carnitine did not affect either the double product (heart rate X systolic blood pressure) at maximal pacing (ST depression: 2.3 +/- 0.2 mm, +/- SEM) or the tolerated pacing time. Intravenous carnitine, in the dose given, is of no therapeutic benefit in myocardial ischemia precipitated by tachycardia. It could be effective when free fatty acids are elevated as during catecholamine stimulation.