Hypertrophic cardiomyopathy (HCM) carries a relatively high risk of sudden death, particularly in young people.^1,2 To date, the clinical significance of heart rate variability (HRV) in patients with HCM is still controversial.^3,4 Our study aimed to analyse HRV in a relatively large cohort of children and young patients with HCM, and to assess potential correlations with clinical markers of sudden death.

METHODS

In all, 53 patients diagnosed with HCM between the ages of 18 and 40 years and body surface area-matched controls were included in this study. The diagnosis of HCM was based on echocardiographic evidence of increased wall thickness, 2 standard deviations (SD) or more compared with age, sex and body surface area-matched people. Maximal ventricular wall thickness (MWT) was defined as the greatest thickness in any segment and measured as the absolute value and as Z score. At the time of the study, age of patients ranged from 1 to 220 months (mean 75.6 (SD 73.7)). Patients with HCM underwent physical examination, rest electrocardiography, conventional echocardiography, exercise test and 24-h Holter …