Electrocardiographic and genetic characteristics in first degree relatives of hypertrophic cardiomyopathy probands: A descriptive cross-sectional study from Vietnam.

Objectives: In order to study the phenotype-genotype relationship and to better understand the early consequences of the mutation, we would report the spectrum of electrocardiographic and genetic features in the relatives of hypertrophic cardiomyopathy (HCM) patients.

Methods: Participants underwent a comprehensive clinical assessment, electrocardiography, standardized and echocardiography and genetic testing. In probands, next-generation sequencing was performed using the gene panel associated with HCM, while in relatives, Sanger sequencing was used to screen for mutations identified in their individual probands.

Results: A total of 84 participants were included in this study. The interventricular septal and posterior wall thickness was highest in the G+/LVH+ group, followed by the G+/LVH- group, and was lowest in G-/LVH- group. Compared to the normal control group, the pathologic Q wave was statistically more prevalent in the G+/LVH- group. The prevalence of repolarization abnormalities and major abnormalities was highest in the G+/LVH+ group, followed by the G+/LVH- group, and lowest in G-/LVH- group.

Conclusion: Our results suggested that sarcomere mutations have early consequences on myocardial biology. These findings suggest the possibility of implementing a mutation carrier detection model within families affected by HCM, where ECG could play a central role when combined with other relevant clinical factors. Longitudinal studies on a cohort of G+/LVH- patients are required.