Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Cardiac Volume”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 253 records · Page 14Linked to original sources
PubMed1983

Hemodynamic effects of massive peripheral edema.

The possibility that noncardiac massive peripheral edema reduces venous distensibility was investigated in eight patients in the supine and 80-degree head-up tilt position before and after diuretic therapy. After clearance of the edema with diuretic therapy, total blood volume (TBV) was not significantly decreased; therefore, in the supine position the significant (2p less than 0.001) decrease of right atrial pressure, stroke volume, cardiac output, and cardiopulmonary blood volume (CBV) by the diuretics was due to an improvement in venous compliance which resulted in peripheral redistribution of CBV since the ratio CBV/TBV was decreased during diuretic therapy (2p less than 0.001). Furthermore, before diuretic therapy, tilt significantly decreased right atrial pressure, stroke volume, cardiac output, CBV, and the ratio CBV/TBV; but after diuretic therapy, the decrease of the same variables during tilt was significantly (2p less than 0.001) greater. These results indicate that marked peripheral edema considerably decreases venous compliance which can be improved with diuretic therapy.

Adult↗
PubMed1980

Increases in circulating volumes and cardiac size with growth of White-tailed deer (Odocoileus virginianus).

Plasma and blood volumes determined by the T-1824 plasma-hematocrit method increase curvilinearly as captive female and male white-tailed deer (Odocoileus virginianus) grow in body mass from 6 to 61 kg (N = 40) and 9 to 93 kg (N = 34), respectively. Although comparable to other species of Cervidae, the weight-specific blood volume averages 33% larger than the interspecific mammalian value of 66 ml/kg body mass. The heart of white-tailed deer is also large, averaging 0.90% of the body mass (N = 53), about twice the ratio reported for domesticated ungulates. The cardiovascular demands attendant with a tenfold increase of body mass are apparently met by rapid increases in cardiac size (both mass and left intraventricular volume increasing curvilinearly with growth) and minute volume of the cardiac pump (cardiac rate and volume ejected per beat, inversely related to the other), which maintain fewer circulations of blood volume per minute with growth to heavier body size occurring from June to November.

Animals↗
PubMed1999

Pneumoperitoneum in healthy humans does not affect central blood volume or cardiac output.

BACKGROUND: This study addresses the question of whether the elevation of the mean arterial pressure and central venous pressure in response to pneumoperitoneum for laparoscopic surgery is caused by increases in central blood volume and/or cardiac output. METHODS: Eleven patients in good cardiopulmonary health and scheduled for laparoscopic cholecystectomy, with a mean age of 42 years, were included. After induction of anaesthesia with fentanyl and propofol, radial arterial and central venous lines were introduced. The central blood volume and cardiac output were determined by the indicator-dilution technique, using inline densitometric measurements of indocyanine green (ICG). The measurements were made before and after the establishment of pneumoperitoneum by insufflation of carbon dioxide to an intra-abdominal pressure level of 11-13 mmHg. RESULTS: The mean arterial pressure (62+/-6 mmHg) increased after induction of pneumoperitoneum by 40+/-26% (P<0.05) and the central venous pressure increased from 6+/-4 mmHg to 8+/-6 mmHg (P<0.05). The cardiac output (4.3+/-0.9 L/min) and central blood volume (1.5+/-0.5 L) were not affected by the induction of pneumoperitoneum. CONCLUSIONS: In healthy anaesthetized subjects, the elevation of mean arterial pressure and central venous pressure in response to pneumoperitoneum was not caused by enhancement in cardiac output or central blood volume.

Adult↗
PubMed1998

Radiotherapy considerations in patients with Hodgkin's disease who receive mediastinal radiotherapy and anthracycline-containing chemotherapy.

Recent clinical work in breast cancer patients has demonstrated that increasing the cardiac volume encompassment within radiotherapy portals leads to greater cardiac morbidity. In Hodgkin's disease, anthracycline chemotherapy is currently favoured, although mantle radiotherapy after anthracycline chemotherapy carries enhanced cardiac toxicity risks. Where anthracycline-based chemotherapy has produced a good response, with centripetal shrinkage of mediastinal disease, considerable cardiac protection is afforded by subcarinal blocking, either after a specific radiation dose or even by truncating the radiation portal in the subcarinal region from the outset. In the eight patients presented here, standard mantle blocks screened 35% (+/-3.2 SE) of the cardiac volume, particularly the left ventricle, throughout radiotherapy. Subcarinal blocks screened an increasing proportion of the cardiac volume as the spinal level of the blocks became higher. This was shown to occur most steeply over the spinal level D9 to D7, the mean extracardiac volume protection over this range being 21% (+/-3.7% SE) to 56% (+/-4.1% SE). These cardiac protection data were calculated for other block placement levels. The routine adoption of subcarinal/ cardiac blocking is advocated, particularly in conjunction with anthracycline-based chemotherapy, in an attempt to reduce late cardiac morbidity resulting from chemoradiotherapy for Hodgkin's disease.

Adolescent↗
PubMed1998

Effects of PEEP on systemic venous capacitance.

The aim of the present study was to determine effects of positive end expiratory pressure (PEEP) application on peripheral venous capacitance and relate them to concomitant central hemodynamic disturbances. The venous volume-pressure (V/P) relationships were studied in 6 intact anesthetized pigs to describe the effects of PEEP on systemic venous compliance (computed as the slope of the V/P relationship) and unstressed volume (referred to as the extrapolated volume intercept). Cardiac volumes as well as partitioning of circulating blood volume between central (ITBV) and peripheral (PBV) compartments were assessed by thermo-dye dilution techniques. During a 15 cm H2O PEEP application, venous compliance was reduced by 48%, while unstressed volume was increased by 25% and peripheral blood pooling increased from 63 to 74%. As a result, left heart and right ventricular end diastolic volumes were decreased by 8% and by 44%, respectively. It is concluded that increased venous unstressed volume and reduced compliance depicted the distension of the venous tree secondary to PEEP which acted as an impediment to venous return. As a consequence, cardiac output was reduced because of decreased preload.

Animals↗
PubMed2001

Deep inspiration breath hold to reduce irradiated heart volume in breast cancer patients.

PURPOSE: To evaluate the use of deep inspiration breath hold (DIBH) during tangential breast radiation therapy as a means of reducing irradiated cardiac volume. METHODS AND MATERIALS: The Active Breathing Control (ABC) device designed at William Beaumont Hospital, Michigan was used to quantify the potential benefit of radiation delivery during DIBH for five left-sided breast cancer patients. This device initiates a breath hold at a predefined, reproducible lung volume. For each patient, two CT scans were acquired with and without breath hold, and virtual simulation was performed for regular tangent and wide-tangent techniques. The resulting dose-volume histograms were calculated, and the volume of heart irradiated to 25 Gy or more was assessed. RESULTS: The influence of ABC on irradiated heart volumes varied considerably among the five patients. Three patients with substantial cardiac volume in the treatment field during normal respiration showed a significant dose-volume histogram reduction when deep inspiration was applied, with decreases in the heart volume receiving 25 Gy of more than 40 cc observed. For one patient, deep inspiration reduced irradiated cardiac volumes only with the wide-tangent technique, while one patient showed no substantial irradiated volume decrease. CONCLUSION: A DIBH technique during tangential breast irradiation has the potential to significantly decrease irradiated cardiac volume for suitably selected patients. The magnitude of the impact of the breath hold application depends on patient anatomy, lung capacity, and pulmonary function.

Breast Neoplasms↗
PubMed2004

Long-term bed rest-induced reductions in stroke volume during rest and exercise: cardiac dysfunction vs. volume depletion.

Long-term head-down-tilt bed rest (HDT) causes cardiovascular deconditioning, attributed to reflex dysfunctions, plasma volume reduction, or cardiac impairments. Our objective with the present study was to evaluate the functional importance and relative contribution of these during rest and exercise in supine and upright postures. We studied six subjects before (baseline), during [days 60 (D60) and 113 (D113)], and after [recovery days 0 (R0), 3 (R3), and 15 (R15)] 120 days of -6 degrees HDT. We determined cardiac output, stroke volume (SV), mean arterial pressure, and heart rate during rest and exercise in supine and upright postures. Cardiac output and SV decreased significantly in all four conditions, but the time courses differed for rest and exercise. Upright resting SV was decreased by 24 +/- 9% at D60 compared with baseline but had recovered already at R3. Supine exercise SV decreased more slowly (by 5 +/- 8% at D60 and by 18 +/- 4% at D113) and recovered more slowly after HDT termination. Steady-state mean arterial pressure showed no changes. Heart rate had increased by 18 +/- 4% at D60 and had recovered partially at R3. Our data indicate that long-term HDT causes both a rapid, preload-dependent reduction in SV, most evident during rest in the upright position, and a more slowly developing cardiac dysfunction, most evident during supine exercise. However, the ability to maintain blood pressure and to perform sustained low levels of dynamic exercise is not influenced by HDT.

Adaptation, Physiological↗
PubMed1979

Exercise response to simulated weightlessness.

Two bed rest analog studies of space flight were performed; one 14 d and the other 28 d in duration. Exercise response was studied in detail during the 28 d study and following both the 14 d and 28 d studies. This paper relates the results of these studies to physiologic changes noted during and following space flight. The most consistent change noted after both bed rest and space flight is an elevated heart rate during exercise. A second consistent finding is a postflight or postbed rest reduction in cardiac stroke volume. Cardiac output changes were variable. The inability to simulate inflight activity levels and personal exercise makes a direct comparison between bed rest and the results from specific space flights difficult.

Adult↗
PubMed1993

Pulmonary diffusing capacity, capillary blood volume, and cardiac output during sustained microgravity.

We measured pulmonary diffusing capacity (DL), diffusing capacity per unit lung volume, pulmonary capillary blood volume (Vc), membrane diffusing capacity (Dm), pulmonary capillary blood flow or cardiac output (Qc), and cardiac stroke volume (SV) in four subjects exposed to 9 days of microgravity (weightlessness, 0 G). The same subjects were studied standing and supine numerous times preflight and in the week immediately after return from space. DL in microgravity was elevated (28%) compared with preflight standing values and was higher than preflight supine because of the elevation of both Vc (28%) and Dm (27%). The elevation in Vc was comparable to that measured supine in 1 G, but the increase in Dm was in sharp contrast to the supine value (which was unchanged). We postulate that, in 0 G, pulmonary capillary blood is evenly distributed throughout the lung, providing for uniform capillary filling, leading to an increase in the surface area available for diffusion. By contrast, in the supine 1-G state, the capillaries are less evenly filled, and although a similar increase in blood volume is observed, the corresponding increase in surface area does not occur. DL and its subdivisions showed no adaptive changes from the first measurement 24 h after the start of 0 G to 8 days later. Similarly, there were no trends in the postflight data, suggesting that the principal mechanism of these changes was gravitational. The increase in Dm suggests that subclinical pulmonary edema did not result from exposure to 0 G. Qc was modestly increased (18%) inflight and decreased (9%) post-flight compared with preflight standing. Compared with preflight standing, SV was increased 46% inflight and decreased 14% in the 1st wk postflight. There were temporal changes in Qc and SV during 0 G, with the highest values recorded at the first measurement, 24 h into the flight. The lowest values of Qc and SV occurred on the day of return.

Adult↗
PubMed2005

Does subclinical hypothyroidism affect cardiac pump performance? Evidence from a magnetic resonance imaging study.

OBJECTIVES: We sought to assess the effects of subclinical hypothyroidism (SHT) on the cardiac volumes and function. BACKGROUND: The cardiovascular system is one of the principal targets of thyroid hormones. Subclinical hypothyroidism is a common disorder that may represent "early" thyroid failure. METHODS: Thyroid profile was evaluated in 30 females with SHT and 20 matched control subjects. Left ventricular end-diastolic volume (EDV) and end-systolic volume (ESV), stroke volume (SV), cardiac index (CI), and systemic vascular resistance (SVR) were calculated by cardiac magnetic resonance (CMR). Regional greatest systolic lengthening (E1) and greatest systolic shortening (E2) were calculated by tagging CMR. RESULTS: EDV was lower in SHT than in controls (64.3 +/- 8.7 ml/m(2) vs. 81.4 +/- 11.3 ml/m(2), p < 0.001), as well as SV [corrected] (38.9 +/- 7.5 ml/m(2) vs. 52.5 +/- 6.1 ml/m(2), p < 0.001) and CI (2.6 +/- 0.5 l/[min.m(2)] vs. 3.7 +/- 0.4 l/[min.m(2)], p < 0.001). SVR [corrected] was higher in SHT (12.5 +/- 2.5 mm Hg.min/[l.m(2)] vs. 8.6 +/- 1.1 mm Hg.min/[l.m(2)], p = 0.003). The E1 was higher in controls than in SHT at the basal (p = 0.007), equatorial (p = 0.05), and apical (p = 0.008) levels, as well as E2 at the equatorial (p = 0.001) and apical (p = 0.001) levels. All parameters normalized after replacement therapy. A negative correlation between TSH and EDV (p < 0.001), SV (p < 0.001), CI (p < 0.001), and E1 at the apical level (p < 0.001) and a positive correlation between TSH and SVR (p < 0.001) and E2 at the apical level (p < 0.001) were found. CONCLUSIONS: Subclinical hypothyroidism significantly decreased cardiac preload, whereas it increased afterload with a consequent reduction in SV and cardiac output. Replacement therapy fully normalized the hemodynamic alterations.

Adult↗
PubMed1997

Effect of alterations in blood volume on cardiac function during maximal exercise.

Recently, we proposed that the higher stroke volume (SV) and cardiac output (Q) of endurance-trained (ETR) versus untrained (UTR) individuals are attributable primarily to the enhanced diastolic filling of ETR consequent to a larger blood volume (BV). To test this hypothesis, we examined the effects of manipulating BV on the cardiac function of six ETR and six UTR males. Both groups were examined in the control BV condition (BVctl), then ETR were examined immediately following a 500 mL reduction in BV (BVred) and UTR were examined immediately following a 500 mL expansion of BV (BVexp). In BVctl, compared with UTR, ETR had significantly greater BV (16%), maximal diastolic filling rate (47.4%), maximal ventricular emptying rate (24.6%), SVmax (31.6%), Qmax (29%) and VO2max (54.5%). Following BVexp in UTR, there were immediate significant increases in maximal diastolic filling rate (22.5%), SVmax (9.1%), Qmax (8.9%), and VO2max (12.7%). Following BVred in ETR there were immediate significant decreases in maximal diastolic filling rate (27%), SVmax (14.3%), Qmax (14.7%), and VO2max (7.0%). Maximal systolic emptying rate did not change significantly following BVred or BVexp. We conclude that changes in SV and Q consequent to alterations in BV are attributable primarily to changes in diastolic function, and the majority of the higher diastolic filling rate of ETR is due to their larger BV.

Adolescent↗
PubMed1995

Normal stroke volume and cardiac output response during dobutamine stress echocardiography in subjects without left ventricular wall motion abnormalities.

Dobutamine stress echocardiography has become widely utilized for evaluation of coronary artery disease, but the expected responses of stroke volume and cardiac output to the high doses of dobutamine administered in these studies are not known. To determine these responses, stroke volume and cardiac output were measured with 2-dimensional Doppler echocardiography at each stage of dobutamine stress echocardiography and after administration of atropine in 47 patients without resting or inducible wall motion abnormalities. Heart rate increased significantly at each stage of dobutamine infusion and after atropine. Mean blood pressure decreased at the 5 micrograms/kg/min dose, then showed little change. Stroke volume increased 27 +/- 18% from baseline, with significant increases occurring at both the 5 and 10 micrograms/kg/min doses (p < 0.00001). With higher doses of dobutamine, stroke volume tended to plateau or decrease. Mean changes in stroke volume were not significant between the doses of 10, 20, and 30 micrograms/kg/min. The mean change in stroke volume from the 30 to the 40 micrograms/kg/min dose was a significant decrease of 6.3% (p = 0.004); the decrease from the 40 micrograms/kg/min dose to atropine approached statistical significance (p = 0.06). Cardiac output increased throughout dobutamine infusion. Stroke volume during dobutamine stress echocardiography is commonly maximum at a dose of 20 micrograms/kg/min and tends to decline at higher infusion rates. At higher doses, increases in cardiac output are mediated primarily by increases in heart rate.

Aged↗
PubMed1995

Stretch-activated channel blockers modulate cell volume in cardiac ventricular myocytes.

Stretch-activated channels (SAC) are postulated to regulate cell volume. While this hypothesis is appealing, direct evidence is lacking. Using digital video microscopy, we found that pharmacological blockade of SACs alters the cell volume of isolated rabbit ventricular myocytes during hypoosmotic stress. Under control conditions, relative cell volume increased from 1.0 to 1.311 +/- 0.019 after 10 min in 195 mosmol/l solution. The cation SAC blocker gadolinium (Gd3+; 10 microM) reduced the amount of swelling in hypoosmotic solution by 24% and induced a regulatory volume decrease otherwise not observed. In contrast, the anion SAC blocker 9-anthracene carboxylic acid (9-AC; 1 mM) increased swelling by 44% under the same conditions. Based on the direction of SAC currents, Gd3+ and 9-AC are expected to have opposite effects on cell volume. Furthermore, Gd3+ and 9-AC changed cell volume by only approximately 2% in isosmotic solutions when SACs are expected to be closed. This supports the idea that Gd3+ and 9-AC affect stretch-activated transport processes. In contrast, omitting bath Ca2+ did not alter cell volume under iso- or hypoosmotic conditions suggesting stretch-activated Ca2+ influx is not important in setting cell volume. Not all channels can affect cell volume. Opening ATP-sensitive K+ channels with aprikalim (100 microM) or blocking them with glibenclamide (1 microM) did not alter cell volume under isosmotic or hypoosmotic conditions. These data support the idea that SACs are involved in cardiac cell volume regulation.

Animals↗
PubMedDate not supplied

Hemodynamic effects of somatostatin in insulin-dependent diabetic subjects.

The aim of the present study was to evaluate possible hemodynamic effects of somatostatin in insulin-dependent diabetic subjects. For this purpose, 7 insulin-requiring juvenile-onset diabetics were submitted to a short-term infusion of cyclic somatostatin (250 micrograms/h, over 2 h) or saline in randomized order. Somatostatin infusion resulted in a progressive and significant decrease in heart rate, stroke volume, cardiac index and velocity circumferential fiber; on the other hand, left ventricular ejection time was augmented by somatostatin. None of these effects was seen in the saline control study. We conclude that somatostatin exerts a negative inotropic effect in insulin-dependent diabetes.

Adult↗
PubMed2003

The esophageal Doppler monitor in mechanically ventilated surgical patients: does it work?

BACKGROUND: Assessment of cardiac volumes and cardiac output (CO) using a pulmonary artery catheter (PAC) in mechanically ventilated patients can be inconsistent and difficult. The esophageal Doppler monitor (EDM) is emerging as a potential alternative to the PAC. This prospective study evaluated the comparative accuracy between the PAC and EDM for preload assessment and CO in mechanically ventilated surgical patients. METHODS The EDM was placed in 15 patients with PACs in place. A total of 187 simultaneously measured EDM and PAC comparative data sets were obtained. The Pearson correlation (r) was used to compare measurements, with significance defined as a value of p < 0.05. RESULTS: CO measured by EDM and PAC correlated closely (r = 0.97, p < 0.0001). Corrected flow time (FTc), a measure of left ventricular filling, correlated with PAC CO to the same degree as pulmonary capillary wedge pressure (PCWP) when positive end-expiratory pressure (PEEP) was < 10 cm H2O (FTc, r = 0.51; PCWP, r = 0.56). When PEEP was > or = 10 cm H2O, FTc correlated with PAC CO better than PCWP (FTc, r = 0.85; PCWP, r = 0.29). CONCLUSION: FTc correlates with EDM and PAC CO better than PCWP. On the basis of the current study, it is reasonable to conclude that the EDM is a valuable adjunct technology for CO and preload assessment in surgical patients on mechanical ventilation, regardless of the level of mechanical ventilatory support.

Aged↗
PubMedDate not supplied

Cardiovascular risk in patients with growth hormone deficiency: effects of growth hormone substitution.

OBJECTIVE: To review the literature on the increased cardiovascular risk in patients with growth hormone (GH) deficiency and the positive effects of GH replacement. METHODS: We analyze the factors that contribute to cardiovascular risk in GH deficiency, including body composition and lipid profile, and summarize GH treatment strategies and results described in the literature. RESULTS: The prominent clinical finding in patients with GH deficiency is the increased abdominal fat, even in patients with normal weight. Cardiac ejection volume tends to be decreased, and arterial distensibility is diminished. The lipid status is also worsened, accompanied by increased inflammatory markers, such as highly sensitive C-reactive protein. Typically, GH treatment reduces visceral fat and increases muscle mass, changes that diminish cardiovascular risk. Because of direct effects as well as increased hemodynamic performance and increased blood volume, cardiac performance is improved. With GH therapy, total cholesterol and low-density lipoprotein levels decrease by 10% to 20%, and inflammatory markers such as C-reactive protein decline. Carbohydrate metabolism during moderate to long-term treatment is minimally affected, although obese patients with GH deficiency on rare occasion may have hyperglycemia or even diabetes. CONCLUSION: The relevance of the beneficial effects of GH on the cardiovascular system is strongly suggested but not fully proved. The results in a large cohort of GH-treated patients (the KIMS or Pharmacia and Upjohn International Metabolic Surveillance database) demonstrated no difference in cardiovascular risk in comparison with that in a control population after a mean of 3 years of treatment.

Adipose Tissue↗
PubMed1988

Study of the effect of Tensiomin (captopril) in chronic heart failure.

Tensiomin (captopril) was tested in 23 patients with chronic heart failure for 7.5 months on the average. In 9 outpatients suffering from congestive cardiomyopathy the effect of Tensiomin as an adjuvant to digitalis, diuretic, vasodilator etc. was evaluated by non-invasive methods. During the 3-month follow-up period the heart rate was decreased and the PEP/LVET ratio was improved. The parameters calculated from the X-ray examination (cardiothoracic index, cardiac volume index) indicated the regression of cardiomegaly. Radioisotopic circulatory examinations (systolic volume index, cardiac output index) indicated an increase in cardiac performance. In addition to the significant changes of these parameters the patients' clinical state was also improved in all cases as assessed according to the NYHA classification. Significant side effects were not observed during the treatment.

Adult↗
PubMed1983

[Anticipation of surgical results in calcified aortic stenosis as a function of age].

The effects of age on the risks and results of heart valve replacement are often discussed in aortic stenosis, a degenerative condition of elderly patients. We assessed this factor in a study based on two groups of patients operated consecutively between 1968 and 1980. Group A comprised 127 patients of over 65 years of age (range 66 to 79 years, mean 70 +/- 3 years), and Group B: 259 patients of less than 65 years of age (21 to 65 years, mean 53 +/- 9 years). Preoperative assessment showed a higher proportion of women and significantly more severe lesions in Group A: a greater number of patients in functional class 3 or 4, cases of congestive cardiac failure, greater cardiac volumes, lower cardiac index. The incidence of coronary artery disease was also higher. A greater number of aortic valve bioprostheses was used in Group A. Operative mortality was significantly higher in Group A (15 p. 100, compared to 6 p. 100 in Group B: p less than 0.01). The influence of age was independent of other risk factors as shown by a multifactorial analysis taking several prognostic factors into account simultaneously. Long term survival was significantly lower in Group A, but their life expectancy did not differ from that of a control group. The causes of postoperative or late death were the same in both groups. At the end of the 6th year, 66 p. 100 of the survivors of surgery in Group A were in functional classes I or II compared to 77 p. 100 in Group B (NS). These results justify this type of surgery in elderly patients, even at advanced stages of their disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗