The relationship between lung volume and standard scalar ECG parameters in normal subjects.

Although the relationship between abnormalities in the ECG and lung volumes has been well described in patients with chronic obstructive lung disease, little is known about this relationship in normal subjects. We investigated this relationship in normal, supine subjects at lung volumes ranging from residual lung volume to total lung capacity. We found that there was a significant right shift in the frontal axis with increasing lung volume. Over the precordium, R wave amplitude decreased mainly at the lateral leads and S wave amplitude increased chiefly at the anterior leads. These results are consistent with a normal vertical shift and clockwise rotation of the heart with increasing lung volume.