Atrial automatic ectopic tachycardia due to an atrial tumor.

A dilated cardiomyopathy picture has been produced by rapid atrial and ventricular rates sustained for a long period of time in some patients. The ventricular tachycardias have in some instances been associated with ventricular tumors as the cause of the tachycardia. Once the tumor is removed, the tachycardia stops and the heart function improves. Atrial ectopic tachycardias also produce a similar picture, but have not been associated with atrial tumors. Such a case is presented with an atrial rhabdomyoma producing atrial ectopic tachycardia and a dilated, poorly contracting myocardium. The tumor was resected and the tachycardia was immediately abolished. Cardiac function quickly returned to normal.