[Tachycardiomyopathy in patients with and without subacute cardiac pathology. Experiences at the Cardiovascular Center of Merida, Venezuela].

We report our experiences with tachycardia-induced cardiomyopathy. Nine patients (3-56 years old) had incessant supraventricular tachycardia and congestive heart failure. The cardiac eco-Doppler evidenced a significant increase of cardiac volumes and mild tricuspid and mitral regurgitation. The ejection fraction (EF) was 0.31 +/- 0.12, the end diastolic volume was 162 +/- 48 cc and the end systolic volume, 116 +/- 54 cc. Four patients had accessory pathways, 3 atrial flutter, 1 A-V nodal reentrant tachycardia, and 1 ectopic atrial tachycardia. Two patients had Chagasic myocarditis. Only in one chagasic patient a decreased number of tachycardia episodes was achieved, this patient died. The autopsy revealed cerebellar and pulmonary emboli. In the other 8 patients the arrhythmia was well controlled. In these, the ventricular volumes decreased, the EF increased to 0.51 +/- 0.14 (p = 0.00006), and the congestive heart failure remitted. We conclude that incessant tachycardia produces a symptomatic dilated cardiomyopathy in patients with and without structural heart disease. The arrhythmia control is followed by an increase in cardiac function and a remission of heart failure symptoms.