Clinical significance of electrocardiography recordings from a higher intercostal space for detection of the Brugada sign

Background The significance of higher intercostal space electrocardiography (HICS ECG) for the detection of the Brugada sign was investigated. Methods and Results The subjects consisted of 113 cases (108 males, 5 females; mean age, 57 +/-17 years) with incomplete right bundle branch block type QRS morphology and ST-segment elevation (>0.10mV) in the right precordial leads. Obvious structural heart disease was not observed in any of the subjects. The V1-3 leads of the standard 12-lead ECG and the HICS ECG were recorded in the supine position, and the amplitude of the terminal portion of the QRS (J-point) and ST-segment (80ms from the J-point) were measured. In the HICS ECG, there was an increase in the area in which the Brugada sign was detectable (47 leads to 66 leads), and in cases with the Brugada sign, the amplitude of the J-point increased. Conclusions The HICS ECG may be helpful for the detection of the Brugada sign.