Disopyramide reduces membrane responsiveness in atrial muscle and the amplitude of the action potential. Excitability of atrial muscle is decreased. These changes decrease atrial muscle conduction velocity. Action potential duration in atrial muscle fibers is prolonged by disopyramide administration. This occurrence increases ERP. Postrepolarization refractoriness does not occur with disopyramide, and it appears to differ from quini-dine and procainamide in this respect.

Abnormal atrial automaticity may be abolished at disopyramide plasma concentrations that fail to alter either conduction velocity or refractoriness. Disopyramide increases atrial refractoriness in patients pretreated with atropine, suggesting that the primary action of disopyra-mide is a direct one and not a consequence of its anti-cholinergic effect.

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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