Determination of cardiac output by transcutaneous continuous-wave ultrasonic Doppler computer

Chandraratna, P.A.N.; Nanna, Michele; McKay, Charles R.; Nimalasuriya, A; Swinney, Robert; Elkayam, Uri; Rahimtoola, Shahbudin H.

doi:10.1016/0002-9149(84)90718-5

Cited by 134 publications

(29 citation statements)

References 4 publications

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“…Cardiac output was measured by two-dimensional echocardiography (Hewlett-Packard ultrasonography 2500) with a 3.5-MHz phasedarray transducer using the parasternal short-axis view as previously described (10,20). All measurements were made by a certified echotechnician according to the guidelines of the American Association of Echocardiography.…”

Section: Autonomic-cardiovascular Functionmentioning

confidence: 99%

Increased abdominal-to-peripheral fat distribution contributes to altered autonomic-circulatory control with human aging

Christou¹,

Jones²,

Pimentel³

et al. 2004

American Journal of Physiology-Heart and Circulatory Physiology

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. Increased abdominal-to-peripheral fat distribution contributes to altered autonomic-circulatory control with human aging. Am J Physiol Heart Circ Physiol 287: H1530 -H1537, 2004. First published June 3, 2004 10.1152/ajpheart. 00322.2004.-Autonomic nervous system (ANS) control of the circulation is altered with aging in adult humans. Similar changes are observed in obesity, particularly abdominal obesity. To determine whether age-associated differences in ANS-circulatory function can be partially explained by increased body fatness, we examined ANS function and three expressions of adiposity (total body fat, abdominal body fat, and abdominal-to-peripheral body fat distribution; dualenergy X-ray absorptiometry) in 43 healthy men: 27 young (25 Ϯ 1 yr) and 16 older (65 Ϯ 1). ANS functions assessed included 1) autonomic support of arterial blood pressure (BP; radial artery catheter), i.e., the reduction in BP during versus before acute ganglionic blockade (GB; intravenous trimethaphan); 2) baroreflex buffering, i.e., the increase in systolic BP with continuous incremental and bolus infusions of phenylephrine during versus before GB; 3) cardiovagal baroreflex sensitivity (Oxford technique); and 4) heart rate variability (time-and frequency-domain analyses). Covarying for abdominal-toperipheral fat distribution reduced or abolished age-related differences in ANS support of BP, cardiovagal baroreflex sensitivity, and heart rate variability but did not affect age-related differences in baroreflex buffering. Covarying for abdominal and total fat had small selective or no effects on age-associated differences in autonomic-circulatory control. Abdominal-to-peripheral fat distribution explains a significant portion of the variance in a number of autonomic-circulatory functions attributable to aging. Therefore, the development of this fat pattern may contribute to several changes in ANS-cardiovascular function observed with aging. These results may help explain how changes in body fat distribution with advancing age are linked to impairments in circulatory control. blood pressure; baroreflexes; cardiac vagal modulation CHANGES IN AUTONOMIC nervous system (ANS) control of the circulation with aging selectively affect physiological function and are a key feature of age-associated cardiovascular disease (13, 40). As such, it is important to understand the factors that contribute to ANS-circulatory dysfunction with aging in adult humans. In this context, we (22, 23) and others (36) previously established that increases in total and abdominal adiposity can explain up to 50 -60% of the increases in muscle sympathetic nerve activity and total norepinephrine spillover with age in healthy men. As recently summarized (39), these findings suggest that increases in total and regional body fat play an important role in sympathetic nervous system activation with human aging.Recently our laboratory demonstrated that other ANS-cardiovascular functions are altered with aging even in healthy men, including greater tonic ANS support of arter...

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Section: Autonomic-cardiovascular Functionmentioning

confidence: 99%

Increased abdominal-to-peripheral fat distribution contributes to altered autonomic-circulatory control with human aging

Christou¹,

Jones²,

Pimentel³

et al. 2004

American Journal of Physiology-Heart and Circulatory Physiology

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“…ml/min) was determined from the data of the cross-sectional area of the aortic valve and the maxi mal integral flow velocity in the ascending aorta during early systole with the use of a Hewlett-Packard (7700 20a) 3.5-MHz duplex scanner. The CO (1/min) was determined from SV and HR [29][30][31]. The intra-and intcrobserver variability of this method has been re ported to be less than 10% [30].…”

Section: Macrocirculationmentioning

confidence: 99%

“…The CO (1/min) was determined from SV and HR [29][30][31]. The intra-and intcrobserver variability of this method has been re ported to be less than 10% [30]. Stroke index (SI) and cardiac index (Cl) are SV and CO per square meter body surface area.…”

Section: Macrocirculationmentioning

confidence: 99%

Long-Term Effects of Recombinant Human Erythropoietin on Macro-and Microcirculation in Chronic Hemodialysis Patients

Wirtz¹,

Leunissen²,

Kuijk³

et al. 1993

Blood Purif

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Recombinant human erythropoietin therapy (ReHuEpo) at short term leads to an increase in systemic vascular resistance and to a decrease in cardiac index and skin microcirculatory flow. Long-term adaptive changes might occur. We studied the effects of ReHuEpo therapy on macrocirculation and skin microcirculation in 8 normotensive and normovolemic hemodialysis patients before and after, respectively, 4 and 14 months of treatment. The reported macrocirculatory changes at short term were at long term not significantly different as compared with the initial values. The mean arterial pressure remained unaltered, as might be explained by the slow correction of the hematocrit and the decrease in cardiac output in all initially long-lasting normotensive patients who were maintained normovolemic. Left ventricular end-diastolic dimensions decreased, and also the left ventricular muscle mass decreased, depending on the initial left ventricular muscle mass. The skin oxygenation improved, whereas the maximal capillary flow decreased both at short- and long-term ReHuEpo treatment. The number of capillaries in the nail fold remained unchanged. However, the percentage of tortuosity decreased significantly during ReHuEpo therapy.

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“…A mild increase was seen in the levels of all three measured hormones; however, only the change in norepinephrine level was statistically significant (from 721 ± 520 to 842 + 634 pg/ml; p < .02). Regression analysis between hormonal changes and changes in the various hemodynamic 6.0 2.9 ng/ml/hr for plasma renin concentration).…”

mentioning

confidence: 99%

Isometric exercise in patients with chronic advanced heart failure: hemodynamic and neurohumoral evaluation.

Elkayam¹,

Roth²,

Weber³

et al. 1985

Circulation

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We evaluated the hemodynamic effects of isometric exercise in 53 patients with congestive heart failure (CHF) and compared them with those found in 10 normal subjects. In both groups, isometric exercise increased heart rate and blood pressure. Systemic resistance increased in patients with CHF (1862 + 520 vs 2126 ± 642 dyne-sec-cm-5; p < .001) but not in normal subjects (1359 + 268 vs 1380 ± 252 dyne-sec-cm-5). Cardiac index and stroke volume index increased mildly but not significantly in the normal subjects (2.8 0.5 vs 3. 1 ± 0.7 liters/min/m2 and 46 + 8 vs 47 ± 7 mI/M2) and showed a significant fall in the patients with CHF (2.1 ± 0.6 to 1.9 ± 0.6 liters/min/m2, p < .01 and 23 ± 7 vs 20 + 7 ml/m2, p < .01). Mean pulmonary arterial wedge pressure increased in patients with CHF from 26 ± 7 to 30 ± 8 mm Hg (p < .001). Although no significant change was found in mean value for stroke work index (21 ± 9 vs 20 + 9 g-m/m2), the individual changes were variable, with marked decrease (>15%) in 17 of the patients. This hemodynamic deterioration could not be predicted from resting hemodynamics, left ventricular ejection fraction, or functional classification. Isometric exercise resulted in no significant change in circulatory catecholamine levels or plasma renin concentration in our 10 normal subjects. In the patients with CHF renin (measured in 12 patients) and epinephrine (measured in 16 patients) also did not change during isometric exercise, but norepinephrine levels (measured in 16 patients) increased significantly. No correlation was found between changes in hormonal levels and any of the hemodynamic changes during static exercise. We conclude that in patients with chronic CHF, isometric exercise can lead to a significant increase in left ventricular outflow resistance and filling pressure and to a fall in cardiac performance. In the presence of CHF, this form of exercise results in a consistent elevation in norepinephrine levels, but there is no correlation between changes in its plasma level and in hemodynamic values. There is considerable individual variation in the hemodynamic response, with a significant deterioration in cardiac performance in some patients, which cannot be separated by resting hemodynamic values, left ventricular ejection fraction, or clinical status.Circulation 72, No. 5, 975-981, 1985.

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Determination of cardiac output by transcutaneous continuous-wave ultrasonic Doppler computer

Cited by 134 publications

References 4 publications

Increased abdominal-to-peripheral fat distribution contributes to altered autonomic-circulatory control with human aging

Increased abdominal-to-peripheral fat distribution contributes to altered autonomic-circulatory control with human aging

Long-Term Effects of Recombinant Human Erythropoietin on Macro-and Microcirculation in Chronic Hemodialysis Patients

Isometric exercise in patients with chronic advanced heart failure: hemodynamic and neurohumoral evaluation.

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