الفهرس | Only 14 pages are availabe for public view |
Abstract The calcium channel blockers, by virtue of the inhibition of the slow calcium current in exeitable cells, have clinically important effects on the contractile process of cardiac and vascular smooth muscle and on the automatiaty and conduction properties of specialized conducting tissue in the heart. They represent an important advancement in the medical therapy of the major cardiovascular diseases. Results obtained in this study showed that verapamil attenuates the hemodynamic response to haryngoscopy and tracheal intubation in thiopental anaesthesia, verapamil also was used as a hypotensive agent during general anaesthesia with controlled ventilation with pancuronum. Verapamil has no significant effect on serum electrolytes, a point which reflects its safety in cardiac patients. Verapamil produces a complex interaction of alterations in preload, after lead due to its vascular smooth muscle relaxant effect, its negative inotropic effect causes inhibition of myocardial contractility decreasing the myocardial oxygen consumption and decreasing the rate pressure product and decreasing the occurance of ischemia. Resutls obtained in this study showed that verapamil has a pronounced negative inotropic action on the isolated mammalian heart. This action on the heart is thought to occur on the superficially located membrane storage sites for calcium. studies on the vascular smooth muscle of rabbit’s aortic spiral strip revealed that verapamil has a relaxant effect, so it should be given cautiously to those patients with constipation while it could be given safely to patients with bronchial asthma. Experimental work showed that verapamil had an antidysrhythmic effect., It was proven that verapamil had a well evident prophylactic effect against adrenaline-induced dysrhythmias. Experimental studies showed the muscle relaxant effect of verapamil in vitro in isolated frog’s rectus. abdominus and in vivo in gastrocnemius-sciatic nerve preparation and the potentiation of non-depolarizing muscle relaxants., the present data and the previous results of others, suggest that anaesthetists should be aware of such possible interaction in patients receiving verapamil. However, to get a clear and right conclusion, human studies are needed. In conclusion verapamil can be, used for atteuuation of hemodynamic response during laryngoscopy and tracheal intulaturn especially for cardiac and neurosurgical operations and as a hypotensive agent during general anesthesia. |