Purpose/Hypothesis: The project of...

Purpose/Hypothesis: The project of this study was to determine if variations in supine material part position affect the mean QK axis of a standard 12-lead electrocardiogram (ECG) Number of Subjects: Twenty-five healthy physical therapy close examiners (17 females, 8 males) offered for the study. The single exclusion criterion was inability to attain or tolerate the supine position. Materials/Methods: about completion of informed consent, bring under rules were placed supine with chest, arms, and leg expos Electrode were then affixed according to standard protocol. Tape was used to insured electrodes in position. A resting 12-lead ECG was then obtained onward each subject in each of three positions: supine 0?°; supine - stock flexed 30?°; supine - stem flexed 60?°. Table angle was risk via goniometer with order of angle presentation randomized for all make subordinates Mean QRS axis values were automatically calculated by way of the electrocardiograph. Subject n was determined from power analysis. Data Analysis: Interrater reliability for electrode placement was determined from intraclass correlation (0.99). One-way repeated measures ANOVA was used to identify differences between mean QR axis and position. Significance was establish at [alpha] =.05 and a Bonferroni adjustment was made for multiple comparisons. Results: All subjects' mean QR axes changed as a function of dead body position. These changes were as follow: 0?°- 30?° = 33?°; 30?°- 60?° = 42?°; 0?°- 60?° = 63?° Significance differences were base between 0?°- 60?° (p.= 005) and 30?°- 60?° (p = 002) Conclusions: Variations in supine material part position toward trunk flexion appear to affect the mean QR axis. Clinical Relevance: Given that the mean QR axis is used as a diagnostic tool, variations in the supine position may show spurious results. We recommend that standard supine protocol (0?°) be applyed whenever accurate determination of the mean QR axis is required.

A Caldwell, D Galindo, K Straznicky, D Shaw. Dept of Physical Therapy, Southwest Texas State University, San Marcos, TX

Copyright Cardiopulmonary Physical Therapy Journal Dec 2003

Provided by means of ProQuest Information and Learning Company. All rights Reserved