THE CARDIAC ARRHYTHMIAS

The presence of a cardiac arrhythmia is an indication for treatment only when the abnormal rhythm interferes with cardiac efficiency. Sinus arrhythmia is normal and requires no treatment. Occasional extrasystoles, or even short bouts of paroxysmal tachycardia, may occur in healthy hearts with no effect on cardiac efficiency. Minor degrees of heartblock and atrial fibrillation with a slow ventricular rate are indications of cardiac damage, but do not in themselves limit the capacity for effort. In treating all arrhythmias attention should be directed primarily to the maintenance of ventricular efficiency, and in some atrial disorders, e.g. fibrillation, this can be done without fundamental change in the abnormal rhythm.