Novel electrocardiographic features in carriers of hypertrophic cardiomyopathy causing sarcomeric mutations

Objectives: The sensitivity and specificity of the conventional 12-lead ECG to identify carriers of hypertrophic cardiomyopathy (HCM) - causing mutations without left ventricular hypertrophy (LVH) has been limited. We assessed the ability of novel electrocardiographic parameters to improve the detection of HCM mutation carriers. Methods: We studied 140 carriers (G+) of the TPM7-Asp175Asn or MYBPC3-Glnl 061X pathogenic variants for HCM: The G+/LVH+ group (n = 98) consisted of mutation carriers with LVH and the G+/LVH- group (n = 42) without LVH. The control group consisted of 30 subjects. The standard 12-lead ECG was comprehensively analyzed and two novel ECG variables were introduced: RVl < RV2 > RV3 and septal remodeling. A subset of 65 individuals underwent cardiac magnetic resonance imaging and 2D strain echocardiography. Results: Conventional major ECG criteria were sensitive (90%) and specific (97%) in identifying G+/LVH+ subjects. RV1 < RV2 > RV3 and septal remodeling were more prevalent in the G+/LVH- subjects compared to the control group (33% vs 3%, p = 0.005 and 45% vs 3%, p < 0.001, respectively). The combination of RVl<RV2 > RV3 and Q waves and repolarization abnormalities (QR) differentiated between the G+/LVH- subjects and the control group with a sensitivity of 52% and specificity of 97%. The combination of septa] remodeling and QR differentiated between G+/LVH- subjects and the control group with a sensitivity of 64% and specificity of 97%. Conclusions: The novel ECG-parameters RVl < RV2 > RV3 and septal remodeling were effective in identifying G+/LVH-subjects and could be useful in the diagnostics of new suspected HCM patients and in the screening and follow-up of HCM families. (C) 2018 Elsevier Inc. All rights reserved.