[The effect of the co-existence of verapamil and residual propranolol on the left ventricular contractility].
The combined effect of the residual propranolol, which was administrated up to the coronary revasculization, and verapamil, anti-supraventricular tachycardia drug, on the left ventricular contractility was evaluated with left ventricular end-systolic pressure-diameter relationship. Methods; Eighteen sheep were instrumented with ultrasonic crystals on the anterior and posterior wall, endocardium and epicardium. A pressure transducer was placed in the left ventricle. Propranolol (0.15 mg/kg) (n = 6) or verapamil (0.15 mg/kg) (n = 6) or both drugs (n = 6) were administrated intravenously, and cardiac function was evaluated. Results; In combined group, end-systolic pressure-diameter ratio (Emax) was significantly decreased (2.95 +/- 0.24 mmHg/mm) as compared to the control group (7.95 +/- 0.83), propranolol group (6.27 +/- 0.78), and verapamil group (4.54 +/- 0.77). Conclusion; Co-existence of propranolol and verapamil significantly decreased cardiac contractility. Therefore verapamil should be administrated carefully in the presence of residual propranolol, and the co-existence of both drugs must be limited.
Sugi
K
K
First Department of Surgery, Yamaguchi University of Medicine, Ube, Japan.
Mori
F
F
Miyamoto
M
M
Esato
K
K
D000818:Animals; D003864:Depression, Chemical; D003971:Diastole / Q000187:drug effects; D004357:Drug Synergism; D006352:Heart Ventricles / Q000187:drug effects; D009200:Myocardial Contraction / Q000187:drug effects*; D009204:Myocardial Revascularization; D011433:Propranolol / Q000008:administration & dosage / Q000494:pharmacology*; D012756:Sheep; D014700:Verapamil / Q000008:administration & dosage / Q000494:pharmacology*
D011433:Propranolol; D014700:Verapamil