Effect of the Skeletal Muscle Relaxant Dantrolene Sodium on the Isolated, Perfused Heart

Abstract

Summary The literature indicates that dantrolene sodium has produced negligible cardiovascular changes in intact dogs and in patients, but caused depression in the isolated perfused heart. In nine consecutive experiments rat hearts were perfused by means of a modified Langendorff preparation with 3.5% bovine albumin in buffered, mammalian Ringer's solution. Perfusion pressure and temperature were kept constant. Flow was measured with an infrared drop counter. Continuous recordings were made of heart rate, coronary flow, resting length, intraventricular pressure, force displacement and their first derivatives. Statistical analysis of all parameters before and during the perfusion with dantrolene sodium solution showed no significant changes for the same period of time. These results show that dantrolene sodium has no effect and do not confirm recent publications which reported a marked myocardial depression by dantrolene sodium.