The effect of body position on P-wave axis

Author

Ng, J. ; Sahakian, AV ; Swiryn, S.

Author_Institution

Northwestern Univ., Evanston, IL, USA

fYear

2001

fDate

2001

Firstpage

313

Lastpage

316

Abstract

Changes in body position are known to change the electrical axis of the heart, resulting in changes in the QRS amplitude, ST segment shifts and T-wave inversions. We investigated the effect of body position changes on the frontal-plane P-wave axes of 10 healthy volunteers. The subjects were monitored using three accelerometers recorded with two ECG channels. The 10 subjects followed a protocol of standing, sitting, walking, lying supine and lying on their right and left sides for five minutes each. Median P-wave and QRS vectors in the frontal plane were computed. With standing, sitting, right and left positions, the P-axis had mean shifts of 10±11 deg, 7±12 deg, 2±11 deg and 12±6 deg, respectively, when compared to the supine position. When compared to QRS shifts, P-wave shifts were larger, with more variability, and were poorly correlated with QRS axis shifts

Keywords

acceleration measurement; angular measurement; biomechanics; biomedical measurement; electrocardiography; patient monitoring; ECG channels; P-wave shifts; QRS amplitude; QRS axis shifts; ST segment shifts; T-wave inversions; accelerometers; body position changes; frontal-plane P-wave axis; heart electrical axis; lying; median P-wave vector; median QRS vector; sitting; standing; supine position; variability; walking; Accelerometers; Electrocardiography; Electrodes; Heart; Legged locomotion; Lungs; Monitoring; Protocols; Thigh; Voltage;

fLanguage

English

Publisher

ieee

Conference_Titel

Computers in Cardiology 2001

Conference_Location

Rotterdam

ISSN

0276-6547

Print_ISBN

0-7803-7266-2

Type

conf

DOI

10.1109/CIC.2001.977655

Filename

977655