Studies on the effects of glucagon on ouabain-induced cardiac disorders using the PISA method

This paper presents the application of a newly developed noninvasive system (PISA; Phase-Invariant Signature Algorithm) in the early detection and quantification of the effects of glucagon on the ouaban-induced electrophysiological disturbances in the heart of the dog. Three doses (20, 30, and 40 migrograms/kg) of ouabain were administered intravenously to each of six anesthetized dogs and broadband ECGs were recorded on FM tape for 100 min. The records were analyzed for PISA signatures and indexes at 20, 40, 60, 80, and 100 min after ouabain administration. There were dose-dependent increases in the PISA indexes. Ouabain (20 micrograms/kg) did not produce any observable changes in the conventional ECG, although it produced significant increases in the PISA indexes. In a second group sox dogs, glucagon (50 micrograms/kg) was administered intravenously 20 min after ouabain (40 micrograms/kg) administration and the ECGs, both conventional and for PISA analysis, were recorded for a further period of 80 min. Glucagon reversed the effects of ouabain on the PISA indexes. These indicate that the PISA method has the capability of early detection and quantitication of drug-induced cardiac disorder.