Characterization of Myocardial Recovery in Patients With Tachycardiomyopathy

BACKGROUND: The degree and time course of improvement in left ventricular (LV) function with treatment in patients with tachycardiomyopathy (TCMP) is highly variable. This study aims to clinically characterize the recovery of TCMP based on the extent and course of improvement in LV function and identify predictors of complete myocardial recovery. METHODS: In this prospective, single-center, observational study, patients with suspected TCMP who underwent successful tachyarrhythmia termination/control were included. Clinical and echocardiographic assessment of LV function was done at baseline, within 1 h after tachyarrhythmia termination, 24 h later, and at 12 weeks follow-up. RESULTS: Ninety-nine patients were enrolled in the study. Six patients had immediate normalization of LV ejection fraction (LVEF) with reversion to sinus rhythm and were labeled as "pseudo-TCMP"; the remaining 93 patients were included in the analysis. Based on complete versus partial normalization of LVEF at 12-week follow-up, 50 patients (53.8%) were labeled as completely recovered TCMP and 43 (46.2%) as partially recovered TCMP respectively. Causative arrhythmias included atrial fibrillation (38%), focal atrial tachycardia (28%), atrial flutter (22%), ventricular arrhythmias (11%), and orthodromic re-entrant tachycardia (2%). The LVEF at presentation was 0.25 ± 0.05 which improved to 0.36 ± 0.11 within 1 h after tachycardia termination (p < 0.0001), 0.41 ± 0.14 24 h later (p = 0.009) and to 0.52 ± 0.12 at 12 weeks follow-up (p < 0.0001). Male gender was the only differentiating statistically significant variable between completely recovered and partially recovered TCMP, 24 (48%) versus 30 (69.7%) respectively (p = 0.0339). CONCLUSION: Nearly half of the TCMP patients have complete recovery of LV function at 12 weeks follow-up, while the other half have a partial recovery only. There was no robust predictor of complete myocardial recovery.