PJ3-047 Site Specific Effects of Quinidine on Repolarization Abnormalities in Patiens with Brugada Type ECG by Using Body Surface Mapping System

Brugada syndrome (BS) is characterized by ST-elevation in leads V1-3, and coexistence of the early repolarization in the left-lateral or inferior leads has been reported as a predictor of VF episodes. Quinidine is a candidate of terapeutic drugs and decreases ST level in some patients. We evaluate the effects of quinidine on ST elevation in three ventricular sites (RVOT, Inferior part and LV) by using body surface mapping system (BSM).We enroled 36 patients with BS-type ECG (asymptomatic 22 pts, VF 11 pts). We recorded ECGs and BSM before and after administration of quinidine (200mg,p. o.) and measured the ECG parameters and the voltage of the ST segment 20ms after J point (ST 20) by the BSM. There were no differences in RR,PQ, and QRS intervals before and after quinidine administration. ST elevation (V2) was attenuated after quinidine treatment (before: 0.28± 0.14mV,v. s. after: 0.23 ± 0.13mV, p=0.03). BSM: ST20 was the highest in the RVOT before quinidine treatment. Quinidine attenuated the ST elevation in the RVOT in VF group (before: 0.23±0.16 mV, v.s. after: 0.16±0.12 mV, p<0.01) and asymptomatic group (before: 0.20±0.13 mV,v.s. after: 0.18± 0.12 mV, p<0.01) but not in other areas. Quinidine improved repolarization abnormality in the RVOT specifically, but not in other areas. The mechanism of the ST elevation in LV and INF might be different from the RVOT.