Diagnostic value of right ventricular dysfunction in tachycardia-induced cardiomyopathy using cardiac magnetic resonance imaging

Background: Predicting tachycardia-induced cardiomyopathy (TIC) in patients presenting with left ventricular (LV) dysfunction and tachyarrhythmias remains challenging. We assessed the diagnostic value of early right ventricular (RV) dysfunction to predict TIC using cardiac magnetic resonance (CMR) imaging. Methods and Results: A total of 102 consecutive patients with newly diagnosed LV dysfunction and atrial tachyarrhythmias were examined. Patients whose LV ejection fraction (EF) improved to ≥50% during a 1-year follow-up were diagnosed with TIC, and with dilated cardiomyopathy (DCM) in those whose did not improve. CMR was performed at a median of 23 days after admission, and the TIC and DCM patients exhibited different distributions of EF and end-diastolic volume (EDV) between the LV and RV (both P<0.001, ANCOVA). TIC patients had significantly lower RVEF/LVEF ratio (1.01±0.23 vs. 1.36±0.31, P<0.001) and higher RVEDV/LVEDV ratio (0.96±0.21 vs. 0.73±0.19, P<0.001) compared with DCM patients, suggesting that RV systolic dysfunction and RV dilatation were observed in TIC. In the multivariate analysis, age, RVEF/LVEF ratio, and RVEDV/LVEDV ratio were significant predictors of TIC, and RVEF/LVEF ratio of <1.05 most highly predicted TIC with a sensitivity of 69.1% and specificity of 91.5% (area under the curve 0.860). Conclusions: Among patients with newly diagnosed LV dysfunction and atrial tachyarrhythmias, age and coexistence of RV dysfunction was a strong predictor of TIC.