Persistent left ventricular dilatation in tachycardia-induced cardiomyopathy patients after appropriate treatment and normalization of ejection fraction

Abstract

Tachycardia-induced cardiomyopathy (TIC) seems to be a form of reversible cardiomyopathy. With recurrence, TIC can be more severe and may increase the risk for sudden cardiac death. We postulate that negative remodeling persists even though ejection fraction (EF) normalizes after appropriate treatment in these patients. We analyzed 2-dimensional echocardiographic parameters of 24 patients with TIC (male: 21; age: 64.1 +/- 15.2 years; atrial arrhythmias: 92%) that improved significantly with treatment (mean time between pretreatment and posttreatment echocardiography: 14 +/- 6 months) and compared them with that of age-, gender-, and ejection fraction-matched control subjects without a history of TIC. The majority of posttreatment echocardiographic parameters showed a significant improvement (P <.05) with treatment in patients with TIC, including left ventricular (LV) ejection fraction (31.2% +/- 8.2% to 55.0% +/- 5.7%) and LV end systolic volume index (55 +/- 21 ml/m(2) to 33 +/- 13 ml/m(2)). There was no significant difference in LV end diastolic volume index (78 +/- 22 ml/m(2) to 72 +/- 22 ml/m(2), P = .15). However, when compared with age-, gender-, and ejection fraction-matched control subjects, posttreatment echocardiographic parameters in TIC patients showed significant differences (TIC vs control group) in LV end systolic volume index (33 +/- 13 ml/m(2) vs 22 +/- 5 ml/m(2)), LV end diastolic volume index (72 +/- 22 ml/m(2) vs 51 +/- 12 ml/m(2)), and cardiac index (2.6 +/- 0.8 l/min/m(2) vs 1.8 +/- 0.6 l/min/m(2)). Although the majority of echocardiographic parameters, including EF, improved significantly with treatment in TIC patients, LV dimensions and volumes remained significantly elevated when compared with control subjects, indicating persistence of negative LV remodeling, even after appropriate treatment and normalization of EF at a mean follow-up of 14 months.