Characteristics of Primary Bradyarrhythmia in Hypertrophic Cardiomyopathy: A 10-Year, Single-Center Analysis.

BACKGROUND

Secondary bradyarrhythmias in hypertrophic cardiomyopathy (HCM) have been extensively reported. The prevalence and characteristics of primary bradyarrhythmias in HCM have yet to be investigated.

METHODS

We retrospectively enrolled 101 consecutive patients with HCM who were referred to the arrhythmia center from May 2010 to October 2020. The clinical features of patients with bradyarrhythmias were analyzed.

RESULTS

Twenty-nine (28.7%) patients had primary bradyarrhythmias, and six (5.9%) patients had secondary third-degree atrioventricular block (AVB). Of the 29 patients, 17 (58.6%) had sinus node dysfunction (SND), 14 (48.3%) had AVB, and two (6.9%) had both SND and AVB. The median age was 62 years old, and 69% were male. Six (20.7%) patients had left ventricular obstructive outflow tract obstruction, 15 (51.7%) had a history of syncope, and one (3.4%) had a family history of HCM. Most patients (86.2%) had New York Heart Association functional class I or II, and the median left ventricular ejection fraction was 63%. A total of 22 patients received pacemaker implantation, including 17 (77.3%) dual-chamber pacing, four (18.2%) single-chamber ventricular pacing, and one (4.5%) cardiac resynchronization therapy.

CONCLUSIONS

Primary bradyarrhythmias need to be evaluated in HCM patients with arrhythmia-related symptoms. Patients with HCM might need pacemaker implantation for primary bradyarrhythmias.