Determination of Cardiac Output by Doppler Echocardiography in Apparently Healthy, Non-Athletic Men Aged 20-70 Years

Abstract

In order to obtain reference values related to age, the cardiac output (CO) was measured by pulsed Doppler in 92 apparently healthy, non-obese, non-athletic men aged 21-69 (mean 43) years with an Irex Meridian system. The aortic flow was recorded from the apical window with the sampling volume in the left ventricular outflow tract. The integral of maximum velocity was calculated by planimetry. The aortic diameter was taken as the distance between insertion of anterior and posterior cusps on the cross-sectional echocardiogram using the leading edge principle. The mean (± 1 SD) CO was 5.46 ± 1.12 litres/min and the cardiac index 2.81 ± 0.57 litres/min/m2. No significant age-related correlations were observed for heart rate, integral of maximum velocity, stroke volume, CO, or cardiac index, whereas the aortic diameter showed a weak positive correlation with age (r = 0.21 ; p < 0.05). In the subgroup aged 30-70 years, significant positive correlations between age and aortic diameter (r = 0.43; p < 0.001), stroke volume (r = 0.28; p < 0.01), and CO (r = 0.21; p < 0.05) were noted. In 7 male patients with coronary heart disease evaluated by right-sided heart catheterization prior to peripheral artery surgery, CO measured by Doppler correlated well with CO obtained by thermodilution (r = 0.90; p < 0.001).

Normative Reference Values of Cardiac Output by Pulsed-Wave Doppler Echocardiography in Adults

“…We report lower CO in women compared to men and no relation between CO and age in each gender. In a small study of 92 apparently healthy males aged 21 to 69 years, mean CO was 5.46 ± 1.12 l/min and mean CI 2.81 ± 0.57 l/min/m² with no significant age-related correlations of CO, CI, or SV 7 . In a population of 584 healthy volunteers and patients with various cardiac pathologies studied with Dopplerechocardiography, Andrén et al reported a mean CI of 2.7 ± 0.6 l/min/m² 10 .…”

“…After the description of CO measurement using Doppler ultrasound in the 1980's, animal 13,14 and human studies [2][3][4] have demonstrated excellent correlations between CO by Doppler ultrasound and by invasive techniques. Previous studies reporting "normal" CO and/or CI by Doppler-echocardiography are limited by the small sample size 7,8 or by the lack of age-or sex-specific reference values 9,10 . We report lower CO in women compared to men and no relation between CO and age in each gender.…”

“…Despite the routine use of pulsed-wave Doppler-echocardiography for CO assessment, reference values in adults are not well defined. Previous studies reporting "normal" CO and/or CI using Doppler-echocardiography are limited by small sample size 7,8 or by the lack of age-or sex-specific reference values 9,10 and did not provide reference values for obese individuals. The present study aims to establish normative reference values for CO and CI by age-group and by gender in non-obese and in obese adults.…”

Blood pressure response during maximal exercise in apparently healthy men and women

“…Since the data from the Framingham study [18] indicate that there is a continuous relationship between blood pressure and development of cardiovascular disease, it may have been desirable to study the blood pressure response to exercise in individuals exhibiting a wider range of resting blood pressure. However, since the present study was designed to assess normal echocardiographic measurements [12,19], it was necessary to exclude subjects with hypertension in order to avoid possible left ventricular hypertrophy which could have influenced these recordings [20], and possibly also normal physical capacity which was another important factor in this study [ 131. Thus we ensured that the blood pressure at various levels of exercise was obtained in a strictly defined and highly selected normotensive population where age and sex were the main variables.…”

Valid and Reproducible Quantitative Assessment of Cardiac Volumes by Echocardiography in Patients with Valvular Heart Diseases—Possible or Wishful Thinking?

“…In most reported normal ranges of LVSV, CO/CI determined by 2D/3D echocardiography in recent recommendations (LVSV approximately 65 mL, CO approximately 4.2 L/min, CI approximately 2.3 L/min m 2 ) are significantly lower than the comparable ranges determined by Doppler echocardiography) [ 4 , 64 , 65 , 66 , 67 , 68 ]. Interestingly, normal values determined by CMR are still approximately 15% higher than those determined by Doppler echocardiography (LVSV approximately 110 mL, CO approximately 6.8 L/min, CI approximately 3.8 L/min m 2 ) [ 69 ], indirectly indicating that the normal ranges of cardiac volumes reported for 2D/3D echocardiography are too low.…”