Significance of cardiac autonomic neuropathy in risk stratification of Brugada syndrome.

AIMS

Risk stratification in Brugada syndrome (BS) is controversial especially in asymptomatic individuals. The aim of this study was to evaluate the significance of cardiac autonomic neuropathy (CAN) in BS.

METHODS AND RESULTS

Patients diagnosed with Brugada ECG pattern were enrolled in the study. Four standard cardiac autonomic function tests were performed. The presence of >or=2 abnormal test results were considered definite evidence for the presence of CAN. Types 1, 2, and 3 Brugada ECG pattern were found in 28, 56, and 31 patients, respectively. CAN was detected in 13 (46%) patients with type 1 Brugada ECG pattern. In contrast, none of the type 2 or 3 Brugada patients had CAN. Of 13 patients with CAN, 11 had previous history of cardiac events (84%), whereas only 2 of 15 patients without CAN had history of previous cardiac events (13%; P = 0.01). The most noteworthy finding was that all of the type 1 Brugada patients with CAN were male (CAN was not detected in females).

CONCLUSIONS

It was concluded that CAN is an important risk indicator in BS. CAN is more common in men. Male gender, per se, is not an independent risk factor for development of ventricular arrhythmia but also CAN, which is an important risk factor in BS, is more common in men; therefore men are susceptible to the development of cardiac events.