Stroke volume and systolic time intervals: Beat-to-beat comparison between echocardiography and ambulatory impedance cardiography in supine and tilted positions

Abstract

The aim of the study was to compare stroke volume (SV), ejection time (ET) and pre-ejection period (PEP) measurements obtained using a central haemodynamics ambulatory monitoring device based on impedance cardiography (ICG), in supine and tilted positions (60 degrees), with pulsed Doppler echocardiography as a non-invasive reference method. The Holter-type ICG device was used for off-line, beat-to-beat, automatic determination of SV, ET and PEP. ICG data were compared with those obtained simultaneously using pulsed Doppler echocardiography in the ascending aorta from a suprasternal projection, 1 min before and 10 min after tilting. The tests were performed in 13 young, healthy subjects (six men and seven women, aged 23-33 years). Linear regression between the measured values obtained for all subjects was described by the following formulas: SVicg= 13.9 + 0.813 x SVecho (r = 0.857, SEE = 9.03, n = 496), ETicg = 16.8 + 0.987 x ETecho (r = 0.841, SEE=21.3, n = 496), PEPicg= 22.8 + 0.890 x PEPecho (r = 0.727, SEE = 14.6, n = 496). The data showed that ambulatory impedance cardiography gives useful absolute values of SV and systolic time intervals measured in supine and tilted positions.

Central Hemodynamic Variability During Sleep in Subjects with and without Atrial Fibrillation

“…We used a (previously described) wearable, ambulatory impedance cardiography recorder (Reomonitor) [9,10]. This device was constructed for non-invasive acquisition of central haemodynamic data during everyday activity.…”

“…Stroke volume was evaluated using the Kubicek formula [8]. The validity and reliability of impedance cardiography have been reviewed many times [9,10]. Ambulatory monitoring with the Reomonitor was verified using echocardiography in both the supine and tilted positions [10].…”

The effects of pre-ejection period on post-exercise systolic blood pressure estimation using the pulse arrival time technique

“…ICG was defined as the first derivative of the thorax impedance change. It has previously been evaluated as a reasonable technique for PEP measurement when compared to echocardiography (Cybulski et al 2004) and simultaneous recordings of carotid pulse tracing and phonocardiography (Balasubramanian et al 1978 5-mins. 5-mins.…”

Influence of aerobic training on neurohormonal and hemodynamic responses to head-up tilt test and on autonomic nervous activity at rest and after exercise in patients after bypass surgery

“…During the test the following variables were monitored: HR during continuously recorded ECG, BP obtained with mercury sphygmomanometer, and stroke volume (SV), which was determined by impedance cardiography. As described previously, the system allows for the off-line, beat--to-beat evaluation of SV and HR [8][9][10]. Cardiac output (CO) was calculated as a product of SV and HR.…”