The value of quinidine in the prevention of cardiac arrhythmias after pulmonary resection.

A considerable number of patients over the age of 45 years who undergo a lung resection operation develop cardiac arrhythmias during the postoperative period. These arrhythmias may be multiple extrasystoles, atrial fibrillation, or atrial flutter. Multiple extrasystoles do not in themselves influence the cardiac function to any very great extent, but they are often the precursor of the more serious irregularities of atrial flutter and fibrillation. Atrial fibrillation may present itself clinically in one of two ways. It may cause shock with a severe tachycardia and a large pulse deficit, or it may cause no alteration in the general condition of the patient and be noticed on routine examination. When atrial fibrillation is associated with shock it leads to a deterioration in the general condition of the patient and inability to expectorate bronchial secretions adequately. This state persists until the fibrillation has been controlled by digitalis, which may take as long as 48 hours. Although it is rare for atrial fibrillation to cause death following pulmonary resection, it does retard a patient's progress and it is desirable to prevent its occurrence if possible. In the cases reported here, no death was directly attributable to atrial fibrillation, but one patient, who subsequently died from a large pulmonary embolus, had developed acute atrial fibrillation two days after operation, and it is possible that the calf venous thrombosis had developed as a direct result of the peripheral blood stasis during the interval between the onset of atrial fibrillation and its control by digoxin. The value of quinidine in preventing atrial fibrillation post-operatively has been studied in this investigation. Quinidine was chosen in preference to digitalis because quinidine is mainly depressant in its action whereas digitalis is a