Effect of change in body position on resting electrocardiogram in young healthy adults

Abstract

Background: The electrocardiogram (ECG) is recorded in the supine position and values of various parameters are based on calculations made from supine ECG recordings. In certain situations, such as exercise stress testing and evaluation of syncope by the head-up tilt test, the ECG is recorded in the upright position. Thus, it becomes equally important to study and quantify the nature and magnitude of changes seen in the ECG with a change of posture from supine to upright in healthy individuals. Aim: To study and investigate the effect of a change in body position on the frontal plane on ECG. Materials and Methods: Thirty healthy adult subjects (15 male and 15 female) in the age group of 18-25 years were included. The ECG was recorded in four body positions, supine, reclining with the trunk flexed at 70°, sitting upright, and standing. Results: The mean frontal plane QRS axis recorded in the supine and standing positions was comparable. The reclining and sitting ECG show a significant variation of the mean QRS axis as compared to the supine position. The T-wave axis was found to be comparable in the supine and standing positions. The corrected QT (QTc) interval showed a significant change with a change in the body position from supine to standing. Conclusion: All the subjects showed similar ECG changes, but differences in the magnitude of the changes with change in body position. The change in the QTc interval with standing needs to be explored.