Antiischemic and metabolic effects of glutamate during pacing in patients with stable angina pectoris secondary to either coronary artery disease or syndrome X

Abstract The effects of glutamate on anginal threshold, cardiac metabolism and hemodynamics were studied in 11 patients with stable angina pectoris, positive stress test results, and pacing-induced myocardial lactate release due to coronary artery disease (CAD) (n = 9) or syndrome X (n = 2). Data were obtained before, during and after 2 identical periods of coronary sinus pacing, the second being preceded by an intravenous injection of monosodium glutamate 1.2 (n = 7) or 2.5 (n = 4) mg/kg body weight. After glutamate administration, pacing time to onset of angina increased from mean ± standard deviation 103 ± 53 to 166 ± 71 seconds (p In conclusion, augmented provision of glutamate enhances pacing tolerance in stable angina, presumably by a metabolic improvement of cardiac energy production during ischemia.