Characteristic Features of QRST Integral Mapping in Patients With High Risk Brugada Syndrome

BACKGROUND: The characteristic features of QRST integral mapping in the Brugada-type resting ECG of patients at a high risk for life-threatening ventricular arrhythmias were examined. METHODS AND RESULTS: QRST integral mapping was performed in 11 Brugada-type ECG patients with histories of aborted sudden death, spontaneous ventricular tachycardia and fibrillation (VT/VF) or programmed electric stimulation-inducible VT/VF (high risk group); 13 Brugada-type ECG patients without a history of such events (low risk group); and 21 age-matched healthy controls. Individual QRST isointegral maps revealed the minimum integral in the mid-to-right upper chest in 100% and 85% of the control and low risk groups, respectively, whereas this integral was 64% in the upper right back of the high risk group (p<0.05). On the QRST integral departure maps, the abnormal positive departure area (integral value>or=+2 standard deviation) was located in the mid-to-right upper chest in 82% and 8% of the high and low risk groups, respectively (p<0.05). During the follow-up period, sudden death or VF occurred in 4 of 6 high risk patients with both the abnormal findings. CONCLUSION: The abnormal positive departure area in the mid-to-right upper chest and the minimum QRST integral in the right upper back were distinct hallmarks for screening patients with the high risk Brugada-type ECG.