Association between delayed enhancement on cardiac magnetic resonance imaging and arrhythmia in patients with hypertrophic cardiomyopathy

Objective: to observe the association between myocardial fibrosis, detected by delayed-enhancement (DE) cardiac magnetic resonance imaging (MRI) and arrhythmia in patients with hypertrophic cardiomyopathy (HCM).

Methods: forty-eight untreated HCM patients who underwent Cine MR, DE-MRI, 24 h ambulatory Holter electrocardiogram and ECG examinations were recruited. Extent of myocardial fibrosis (fibrosis mass/total LV mass) was assessed using DE imaging. Association between arrhythmias including premature ventricular complexes (PVCS ≥ 200), supra-ventricular tachycardia (SVT), non-sustained ventricular tachycardia (NSVT), atrio-ventricular block (AVB) and intra-ventricular block (IVB) detected by Holter monitoring and ECG with regard to delayed enhancement (DE) on contrast enhanced CMR was analyzed.

Results: myocardial fibrosis was detected in 35 patients. Incidence of arrhythmia was significantly higher in patients with DE than in patients without DE (P < 0.05). Extent of myocardial fibrosis was significantly associated with the QRS duration (r = 0.33, P < 0.001).

Conclusions: myocardial fibrosis detected by DE-CMR was associated with arrhythmia in patients with HCM. DE-CMR might be helpful to detect high-risk HCM patients prone to arrhythmia.