HNN215 Lecture Notes - Lecture 3: Electrical Conduction System Of The Heart, Vascular Smooth Muscle, Cardiac Action Potential
Document Summary
Briefly describe the action of the following classes of cardiac related agents: Beta blockers their mechanise of action is to reduce heart rate, reduce blood pressure and cardiac contractility. They depresses the sinoatrial node rate which then slows the conduction through atrial ventricular node. Antiarrhythmics there are two drug classes with these agents and they are digoxin and amiodarone. The digoxin is to increase the efficiency of the heart by improving cardiac output, influences movement of ions in myocardial fibres and alters activity of the autonomic nervous system. Amiodarone has multiple actions, but primarily works to prolong duration of cardiac action potential. It decreases sa node activity, decreases av conduction, has a weak beta blocking effect. Calcium channel blockers action works on the heart affecting, cardiac contractility & conduction, and vascular smooth muscle & vascular tone. Its mechanism of action are to block inward current of calcium into cells in cardiac conduction system & myocardium.
