Late gadolinium enhancement CMR in patients with tachycardia-induced cardiomyopathy caused by idiopathic ventricular arrhythmias.

BACKGROUND: Idiopathic ventricular arrhythmias in the form of monomorphic premature ventricular contractions (PVC) and/or ventricular tachycardia (VT) can cause tachycardia-induced cardiomyopathy (TICMP). The aim of this study was to determine the prevalence of late gadolinium enhancement (LGE) in patients with TICMP caused by idiopathic ventricular arrhythmias. METHODS: The study population consisted of 298 consecutive patients (174 F/124 M; mean age 45±17 years) with frequent PVCs and/or VT. TICMP was defined as left ventricular ejection fraction (LVEF) of ≤50% in the absence of any detectable underlying heart disease and improvement of LVEF≥15% after effective treatment of index ventricular arrhythmia. RESULTS: Twenty-seven (9.1%) patients found to have LVEF≤50% and diagnosed as presumptive TICMP. Improvement in LVEF after effective treatment of index ventricular arrhythmia was observed in 22 of 27 patients (TICMP group; mean PVC burden of 30.8±9.9%). LVEF did not improve in five of 27 patients (primary cardiomyopathy group; mean PVC burden of 28.8±10.1%). LGE-cardiac magnetic resonance (CMR) imaging was performed in 19 of 22 patients with TICMP and one patient (5%) had LGE. All five patients with primary cardiomyopathy underwent LGE-CMR imaging and four patients (80%) had LGE. CONCLUSIONS: LGE is a rare finding in patients with TICMP caused by idiopathic ventricular arrhythmias. LGE-CMR can be used in the diagnostic work-up of patients with TICMP. Further prospective studies are required to determine the role of LGE-CMR in predicting the recovery of left ventricular systolic dysfunction in patients with presumptive TICMP.