Purging Action of Quinidine Potentiation of Contraction Coupling to Basic Electric Rhythms

Despite the fact that cardiologists differ markedly in their convictions regarding the value and risks of quinidine as well as their methods of its administration, they are the chief users of the drug. An increase in the number of bowel movements with or without mild abdominal distress, more characteristically a nuisance than a serious problem, is a well-known side reaction. This complication of therapy occasionally limits the potential usefulness of quinidine in certain patients with cardiac arrhythmias. A recent report by Garrett and associates' has given basic information concerning the pharmacological effects of quinidine. Two electrical phenomena are recorded normally from the small bowel. One, which has been referred to as the basic electrical rhythm (BER), is an omnipresent, cyclically recurring change in potential in the longitudinal (outer) smooth-muscle layer, and is considered to be the pacesetter or synchronizer of motor function of the bowel. The second type of electric activity consists of a burst of "spike," "fast," or action potentials, which accompany contraction of muscle. The spikes occur only during a restricted or limited portion of each cycle of the BER, specifically near