Exercise-induced and nitroglycerin-induced myocardial preconditioning improves hemodynamics in patients with angina

1 Centro Interdipartimentale per le Tecnologie e gli Ambienti Collegati allo Sport, University of Cagliari, 09100 Cagliari; 2 Clinical and Biological Science Department, University of Turin, 10100 Turin; 4 Cardiology Division, SS Trinità Hospital of Cagliari, 09100 Cagliari; and 3 Sport Medicine Division, CTO Hospital of Iglesias, 09016 Iglesias, Italy Submitted 20 October 2003 ; accepted in final form 2 March 2004 In humans, regional myocardial dysfunction during ischemia may be improved by ischemic and pharmacological preconditioning. We assessed the possibility that exercise- and nitroglycerin-induced myocardial preconditioning may improve global cardiac performance during subsequent efforts in patients with angina. Ten patients suffering from chronic stable angina and ten healthy volunteers were studied. Through impedance cardiography we assessed hemodynamics during a maximal exercise test, which was used as a baseline (Bas test) and considered as a preconditioning exercise. The Bas test was followed by a sequence of maximal efforts performed during the first (FWOP; 30 min after the Bas test) and second (SWOP; 48 h after the Bas test) windows of protection conferred by ischemic preconditioning. Hemodynamics was further evaluated during maximal exercise performed 48 h later with pharmacologically induced SWOP (PI-SWOP) obtained by transdermal administration of 10 mg of nitroglycerin. In the angina patients, FWOP, SWOP, and PI-SWOP delayed the time to ischemia and allowed them to achieve higher workloads compared with the Bas test. Furthermore, heart rate and cardiac output at peak exercise were enhanced during all the preconditioning phases with respect to the Bas test. However, only SWOP and PI-SWOP increased myocardial contractility and stroke volume. No changes in hemodynamics were detectable in the control subjects. This study demonstrates that in patients with stable angina, although hemodynamics during exercise can be positively improved during both FWOP and SWOP, differences exist between these two phases. Furthermore, the mimicking of exercise-induced SWOP by PI-SWOP with transdermal nitroglycerin may represent an important clinical aspect. ischemia; cardiac output; myocardial contractility; nitroglycerin Address for reprint requests and other correspondence: A. Crisafulli, CITAS, Univ. of Cagliari, via Porcell 4, 09100 Cagliari, Italy (E-mail: crisafulli{at}tiscali.it ).