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The effect of verapamil on cardiac sympathetic function.
E C Meyer1, D K Sommers, J C Avenant
1Department of Pharmacology, University of Pretoria, South Africa.
European Journal of Clinical Pharmacology
|January 1, 1991
Summary
Verapamil
Area of Science:
- Cardiology
- Pharmacology
Background:
- Chronic verapamil treatment depletes cardiac noradrenaline stores in rats.
- Systolic time intervals (STI) can indirectly measure cardiac inotrophy and chronotropy.
Purpose of the Study:
- To investigate if verapamil affects cardiac noradrenaline stores in healthy volunteers.
- To assess the impact of verapamil on cardiac function using STI.
Main Methods:
- 8 healthy volunteers received placebo, verapamil, or atenolol intravenously.
- Systolic time intervals (QS2I, LVETI, PEP/LVET) were measured.
Main Results:
- Verapamil pretreatment induced a positive inotropic state.
- Intravenous verapamil after oral pretreatment showed enhanced negative inotropic and chronotropic effects compared to acute verapamil.
Conclusions:
- Initial verapamil inotropy may involve increased intrasynaptic noradrenaline.
- Accentuated negative responses suggest verapamil decreases cardiac noradrenaline storage.