Sinus tachycardia is generally regarded as a symptom and treatment is directed toward the underlying disorder rather than to the tachycardia as such. However, cases are encountered where the cause of the rapid heart action is not clear, or if evident not readily reversible. Under such circumstances, in our experience, no satisfactory measure for the control of the tachycardia has heretofore been available.
Recently it occurred to us that guanethidine (Ismelin), because of its bradycardic properties, might merit a trial.
Report of Cases听
Case 1.听
鈥擜 60-year-old woman was first seen on Aug 15, 1955, complaining of palpitation and substernal distress of two to three month's duration. She had been receiving digitalis daily without relief. Examination showed a regular tachycardia with a pulse rate of 110 to 120 beats per minute. The heart was within normal limits in size and shape. There was a short apical systolic murmur; the heart