title: Effects of verapamil on postextrasystolic potentiation.
abstract: To assess the effects of verapamil on postextrasystolic potentiation (PESP), contrast left ventriculography was performed in ten healthy anesthetized dogs before and after the intravenous administration of verapamil, 0.1 mg/kg. During the contrast ventriculography, a single atrial premature stimulus was introduced. Ejection fractions of a control beat and postpremature beat were measured before and after verapamil. Before verapamil, the mean ejection fractions of the control beat and the postpremature beat were 60 +/- 10 percent and 67 +/- 10 percent, respectively (p less than 0.05). Following the administration of verapamil, the mean ejection fraction of the control beat decreased from 60 +/- 10 percent to 55 +/- 11 percent (p less than 0.05). However, the mean ejection fraction of the postpremature beats increased when compared with the control beats following intravenous verapamil (65 +/- 8 percent and 55 +/- 11 percent, respectively; p less than 0.05). These results suggest that PESP is not inhibited by the administration of intravenous verapamil.
authors.affiliation: Division of Cardiology, Creighton University School of Medicine, Omaha.
authors.forename: A N
authors.initials: AN
authors.lastname: Mooss
authors.forename: D E
authors.initials: DE
authors.lastname: Hilleman
authors.forename: J
authors.initials: J
authors.lastname: Rysavy
authors.forename: M H
authors.initials: MH
authors.lastname: Sketch
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D005117:Cardiac Complexes, Premature / Q000503:physiopathology*; D004285:Dogs; D006339:Heart Rate / Q000187:drug effects; D009200:Myocardial Contraction / Q000187:drug effects; D013318:Stroke Volume / Q000187:drug effects; D014700:Verapamil / Q000494:pharmacology*
chemical_list: D014700:Verapamil