Impact of Prone Position on 12-Lead Electrocardiogram in Healthy Adults: A Comparison Study with Standard Electrocardiogram

Table 2

Effect of prone position on heart rate, mean electrical axis, QRS amplitude, QRS duration, PR, and QTc interval.

Variable	Supine	Prone	value
Heart rate (bpm)	69.5 ± 11.5	73.2 ± 12.4	0.03
Mean QRS vector (degree)	49.8 ± 28	40.5 ± 32	0.015
Mean T wave vector (degree)	43.6 ± 20.3	39.1 ± 20.6	0.86
Mean P wave vector (degree)	43.4 ± 22.6	47.6 ± 27.3	0.36
Mean QRS amplitude in the precordial leads (mV)	7.42 ± 3.1 mV	3.68 ± 1.7 mV	<0.001
Mean QRS amplitude in limb leads (mV)	4.74 ± 0.86 mV	4.68 ± 1.1 mV	0.513
QRS duration	92.8 ± 12.6 ms	84.9 ± 11.9 ms	<0.001
PR interval	155.6 ± 24.8 ms	159.1 ± 27.2 ms	0.37
Mean QTc (ms)	406 ± 18.8	385 ± 64.8	0.05

QTc: Corrected QT interval. Data are expressed as mean ± SE. Statistical significance of differences calculated using the independent sample t-test.