[Characteristics of cardiac arrhythmia in patients with hypertrophic cardiomyopathy].

OBJECTIVE

To investigate the patterns of arrhythmias in patients with hypertrophic cardiomyopathy (HCM) and its relation with the pathology of heart.

METHODS

The clinical data, electrical cardiogram (ECG), Holter ECG recordings, and echocardiograms of 85 patients with HCM were collected and analyzed.

RESULTS

Seventy four (87%) of the 85 patients with HCM had various forms of arrhythmia, including tachycardia in 30 patients with a prevalence of 35.3%, and bradycardia in 21 patients with a prevalence of 24.7%. The incidence rates of intraventricular conduction block and tachycardiac arrhythmia of the 24 HCM patients with syncope history were 45.8% and 50.0% respectively, both significantly higher than those of the 61 HCM patients without syncope history (21.3% and 26.2% respectively, both P > 0.05). The incidence rate of bradycardiac arrhythmia of the 24 HCM patients with syncope history was 50.0%, significantly higher than that of the 61 patients without syncope history (14.8%, P < 0.001). Arrhythmia, especially bradycardia, was more frequent in the patients with hypertrophy in mid-low part of interventricular septum and cardiac apex.

CONCLUSION

Most patients with HCM have various cardiac arrhythmias, and occurrence of syncope and cardiac sudden death in the patients may be caused not only by tachycardia but also by bradycardia. Bradycardia is more frequent in the patients with hypertrophy in mid-low part of interventricular and cardiac apex.