Comparison of Four Noninvasive Techniques to Measure Stroke Volume: Dual-Beam Doppler Echoaortography, Electrical Impedance Cardiography, Mechanosphygmography and M Mode Echocardiography of the Left Ventricle

Abstract

This study compared cardiac stroke volumes using four noninvasive techniques in healthy volunteers: dual-beam Doppler echoaortography, electrical impedance cardiography, mechanosphygmography and M mode echocardiography of the left ventricle. Variations in stroke volume were induced by intravenous atropine in increasing doses and venous tourniquets in the absence and presence of propranolol. Biometrical analysis used correlations and principal components in order to find the common reality, reflected by the four techniques. Three of the four techniques showed good correlations between themselves as well as to the principal component. The correlation closest to the principal component was the electrical impedance cardiography (0.89) followed by the Doppler method (0.87) and the mechanosphygmography (0.84); the results from left ventricular echocardiography (0.66) were poorest. These results can be interpreted in the sense that the first three techniques are of good validity in the noninvasive assessment of stroke volume in man, and the selection of one of these techniques for use in a clinical study should depend on the study’s design and scope.

Twenty-Four-Hour Hemodynamic Effects of Two Different Dihydropyridine Derivatives Assessed by Noninvasive Methods in Patients with Congestive Heart Failure

“…Over all, we found a close relationship between the hemody namic parameters as measured by impedance and mechanocardiopathy. This is in accordance with data of other investigations [23,24],…”

Influence of antihypertensive therapy with cilazapril and hydrochlorothiazide on the stiffness of the aorta

“…Wave velocity (Cw, m/see) was calculated from the distance between the measurement sites (1, m) and the foot-to-foot determined time difference (delta t, sec) in the occurrence of the simultaneously recorded pressure pulses (for details of the applied technique, see Breithaupt et al [18,30]. A blood pressure standardized index of aortic cross-sectional distensibility (2m, no dimension) was determined according to Sinn [31] as 2m = BPm/(C2w x rho x 7.5), (1) where rho = density of blood = 1.06 g x cm -3 and BPm = arterial mean pressure (mmHg), calculated…”

“…Other equivalents, such as aortic input impedance and effective arterial elastance, reflect the pulsatile components of left ventricular afterload [41][42][43]. Aortic stiffness can be assessed most easily by measurement of pulse wave velocity (Cw), with a high Cw indicating increased stiffness and vice versa [14,18,[30][31][32][33][34][35][36][44][45][46][47][48][49][50]. The pulse wave velocity mirrors the average stiffness of the aortic pathway and can provide more information than techniques measuring the aortic diameter at only one defined site [51].…”

Agreement and reproducibility of the estimates of cardiovascular function by impedance cardiography and M‐mode echocardiography in healthy subjects.

“…Correspondence: Dr C. de Mey, Center for Cardiovascular Pharmacology, Mathildenstral3e 8, 6500 Mainz, Germany Cardiovascular effects were assessed by M-mode echocardiography (ECHO) and differentiated transthoracic impedance cardiography (ZCG) as used previously for similar comparisons (Belz et al, 1984;Breithaupt et al, 1990). Measurements were made at 15 (time B1) and 5 min (time B2) before administration of the first dose (time:0) and then at the end of each dosage step:time 0:30, 1:00 and 1:30.…”