A study of influence of chest electrode position upon the electrocardiogram

Abstract

An influence of chest electrodes position upon the electrocardiogram (ECG) was investigated in this study. One hundred twenty one ECGs were used. All these tracings showed that Sv_1+Rv_5 (or Sv_1+Rv_6) was higher than 3.5mV. ECGs were recorded in three ways ; standard electrodes position (N-level) : one intercostal space above the N-level (A-level) ; and one intercostal space below the N-level (B-level). ECGs recording both at A-level and at B-level resulted in a decrease in the number of the point score system. But there were 19 subjects, in whom left atrial overload was newly observed at A-level. Conclusion ; (1) a slight shift of the chest electrode may lead to an erroneous diagnosis of left ventricular hypertrophy. (2) ECG recording at the one interocostal space above the standard position (A-level) may be useful for the diagnosis of left atrial overload.