[Comparison of the effects of regional ischemia and of reperfusion on the hypertrophied heart of spontaneously hypertensive rats and the heart of Wistar-Kyoto rats with isolated perfused heart via the left atrium. Effects of lidocaine, propranolol and verapamil].

: 1. A comparative study between the effects of ischemia and reperfusion on the hypertrophied heart of spontaneously hypertensive rat (SHR) and on the heart of Wistar-Kyoto (WKY) was carried out in working heart conditions. 2. The decrease of coronary flow induced by a coronary occlusion had an equal magnitude in the two groups. In the SHR group, the aortic output became null in 40% of the cases, whereas this effect was never seen in WKY group. 3. In reperfusion conditions, the recovery of haemodynamic values was slower in SHR group. The release of LDH and the rhythmic disturbances were also increased. 4. The perfusion of SHR hearts by lidocaine (4.3 10(-5) M), propranolol (7.7 10(-6) M) and verapamil (1.1 10(-7) M) decreased significantly the heart rate and the aortic output. 5. When these substances were added to the perfusion medium, the deleterious effects of reperfusion were greatly reduced. Aortic output recovered more quickly than his basal values and the enzymatic leakage was decreased. None of the hearts fibrillated after lidocaine and propranolol. Ventricular fibrillation continued in 14% of cases after verapamil compared to 80% of cases in the control group.