Effects of lung volume on body surface electrocardiogram. Isointegral analysis of body surface maps in patients with chronic pulmonary emphysema.
To evaluate the effects of lung volume changes on the body surface electrocardiogram, we performed body surface potential mapping (87 lead points) in 20 normal subjects (group N) and in 21 patients with chronic pulmonary emphysema (group CPE). P-wave, QRS, ST-segment, ST-T and QRST iso-integral maps were constructed. Group-mean maps and the mean value of the maximum (max) and the minimum (min) on each map were compared between group N and group CPE. In group CPE, the body surface distribution of the P, QRS, ST, ST-T and QRST time integrals were all positioned downwards compared with those of group N. In addition, we also detected an increase in the max of P and decreases in the min of P; max and min of QRS; and in max of ST-T and QRST integrals. It was suggested that these changes were caused by the downward shift and clockwise rotation of the heart, and also by the decreased electrical conductivity of the lungs.
D000328:Adult; D000368:Aged; D002908:Chronic Disease; D004562:Electrocardiography / Q000379:methods*; D004566:Electrodes; D005260:Female; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008176:Lung Volume Measurements; D008297:Male; D008875:Middle Aged; D011656:Pulmonary Emphysema / Q000503:physiopathology*; D012119:Respiration; D014672:Vectorcardiography