Usefulness of the electrocardiogram and cardiac magnetic resonance to differentiate tachycardia induced cardiomyopathy from dilated cardiomyopathy in patients admitted for heart failure

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background In patients admitted for heart failure (HF) with reduced left ventricular ejection fraction (LVEF) and a concomitant high-rate supraventricular tachyarrhythmia (SVT) it is challenging to predict LVEF recovery after heart rate control and distinguish tachycardia-induced cardiomyopathy (TIC) from dilated cardiomyopathy (DC). The role of cardiac magnetic resonance (CMR) and the electrocardiogram (ECG) in this setting remains unsettled. Methods Forty-three consecutive patients admitted for HF due to high-rate SVT and LVEF <50% undergoing CMR in the acute phase were retrospectively included. Those who had LVEF >50% at follow up were classified as TIC and those with LVEF <50% were classified as DC. Clinical, laboratory, CMR and ECG findings were analyzed to predict LVEF recovery. Results Twenty-five (58%) patients were classified as TIC. Patients with DC had wider QRS (121.2 ± 26 vs 97.7 ± 17.35 ms; p = 0.003). On CRM the TIC group presented with higher LVEF (33.4 ± 11 vs 26.9 ± 6.4% p = 0.019) whereas late gadolinium enhancement (LGE) was more frequent in DC group (61 vs 16% p = 0.004). On multivariate analysis, QRS duration ≥100 ms (p = 0.027), LVEF < 40% on CMR (p = 0.047) and presence of LGE (p = 0.03) were identified as independent predictors of lack of LVEF recovery. Furthermore, during clinical follow-up (median 60 months) DC patients were admitted more frequently for HF (44% vs 0%; p < 0.001) than TIC patients (Figure 1). Conclusion In patients with reduced LVEF admitted for HF due to high-rate SVT, QRS duration ≥100 ms, LVEF <40% on CMR and presence of LGE are independently associated with lack of LVEF recovery and worse clinical outcome.