A comparison between the automatized impedance cardiography and pulsed-wave Doppler echocardiography methods for measurements of stroke volume (SV) and systolic time intervals (STI)
Cybulski, G.; Miśkiewicz, Z.; Szulc, J.; Torbicki, A.; Pasierski, T.
Journal of Physiology and Pharmacology An Official Journal of the Polish Physiological Society 44(3): 251-258
1993
ISSN/ISBN: 0867-5910 PMID: 8241526 Document Number: 421860
Stroke volume (SV) and systolic time intervals (STI) were measured automatically using impedance cardiography signals (ICG) and compared with those obtained by pulsed-wave Doppler echocardiography using the apex approach. The comparison was made in 9 healthy male subjects, mean age 24.9 +/- 12.2 years, using recordings of 10 heart cycles simultaneously obtained by the two methods. During measurements the subjects rested in the supine position. There were no differences between mean values of SV determined by the two methods as well as between mean values of ejection time (ET) (p > 0.8 and p > 0.9, respectively). The pre-ejection period (PEP) estimated by ICG was 22 ms longer than that determined by echocardiography (p < 0.001). The relationship between SV values measured by impedance cardiography (SVA) vs those calculated by echocardiography (SVE) was found to be close to the line of identity in the range of measurements. The regression equation for SV was: SVA = 0.784.SVE + 15 (r = 0.69, p < 0.001, SEE = 10.7 ml). We conclude that automatic determination of SV and ET from ICG signals provides results comparable in absolute values with those obtained by the pulsed wave Doppler ultrasonocardiography using the apex approach for subjects remaining in the supine position.