International heart journal
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The right ventricular outflow tract (RVOT) is considered the arrhythmogenic region that gives rise to Brugada syndrome. To obtain a better understanding of this substrate, we performed electroanatomic mapping of the right ventricle (RV) in patients with Brugada syndrome. ⋯ The low voltage zone area (< 1.5 mV) was larger (16.1% versus 7.8%, P < 0.01) and the bipolar electrogram duration was greater (81.6 ± 7.8 ms versus 53.4 ± 5.6 ms, P < 0.01) in the patients with Brugada syndrome versus the control patients; the bipolar electrogram duration was greater in the septal portion and free wall of the RVOT. Our data suggest that regional endocardial conduction slowing based on structural abnormalities exists at the RVOT in Brugada syndrome.
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High mobility group box 1 (HMGB1), which has properties similar to those of proinflammatory cytokines, is released from activated immune cells and necrotic cells. It is known that cardiopulmonary bypass (CPB) induces systemic inflammation and aortic cross-clamping induces myocardial ischemia. This study was conducted to clarify whether HMGB1 is released in CPB-supported cardiac surgery in comparison to off-pump coronary artery bypass grafting (OPCAB) where CPB is not used. ⋯ IL-6 and IL-10 increased after aortic declamping in the CPB group and after coronary revascularizations in the OPCAB group. Based on these results, we conclude that the major factor involved in the increase in HMGB1 level might be myocardial ischemia/reperfusion during cardiac surgery. Activation of immune cells, altered tissue perfusion, and pulmonary ischemia and reperfusion could be additional factors that increase the HMGB1 level in CPB-supported cardiac surgery.