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Eyeington CT, Canet E, Cutuli SL, Ancona P, Brown AJ, Jenkins E, Taylor DM, Eastwood GM, Bellomo R. COMBED: Rapid non-invasive Cardiac Output Monitoring Baseline assessment in adult Emergency Department patients with haemodynamic instability. Emerg Med Australas 2022; 34:528-538. [PMID: 34981648 DOI: 10.1111/1742-6723.13926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/03/2021] [Accepted: 12/06/2021] [Indexed: 11/03/2022]
Abstract
OBJECTIVE The application of rapid, non-operator-dependent, non-invasive cardiac output monitoring (COM) may provide early physiological information in ED patients with haemodynamic instability (HI). Our primary objective was to assess the feasibility of measuring pre-intervention (baseline) cardiac index (CI) and associated haemodynamic parameters. METHODS We performed a prospective observational study of adults shortly after presentation to the ED of a large university hospital with tachycardia or hypotension or both. We applied non-invasive COM for 5 min and recorded CI, mean arterial pressure (MAP), stroke volume index (SVI) and systemic vascular resistance index (SVRI). We assessed for differences between those presenting with hypotension or hypotension and tachycardia with tachycardia alone and between those with or without suspected infection. RESULTS We obtained haemodynamic parameters in 46 of 49 patients. In patients with hypotension or hypotension and tachycardia (n = 15) rather than tachycardia alone (n = 31), we observed a lower MAP (60.8 vs 87.7, P < 0.0001), CI (2.8 vs 3.9, P = 0.0167) and heart rate (85.5 vs 115.4, P < 0.0001). There was no difference in SVI (33.7 vs 33.4, P = 0.93) or SVRI (1970 vs 2088, P = 0.67). Patients with suspected infection had similar haemodynamic values except for a lower SVRI (1706 vs 2237, P = 0.011). CONCLUSIONS Rapid, non-operator-dependent, non-invasive COM was possible in >90% of ED patients presenting with HI. Compared with tachycardia alone, patients with hypotension had lower CI, MAP and heart rate, while those with suspected infection had a lower SVRI. This technology provides novel insights into the early state of the circulation in ED patients with HI.
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Affiliation(s)
- Christopher T Eyeington
- Department of Intensive Care, Austin Hospital, Melbourne, Victoria, Australia.,Division of Anaesthesia, Cambridge University Hospitals NHS Trust, Cambridge, UK
| | - Emmanuel Canet
- Department of Intensive Care, Austin Hospital, Melbourne, Victoria, Australia
| | - Salvatore L Cutuli
- Department of Intensive Care, Austin Hospital, Melbourne, Victoria, Australia
| | - Paolo Ancona
- Department of Intensive Care, Austin Hospital, Melbourne, Victoria, Australia
| | - Alistair J Brown
- Department of Intensive Care, Austin Hospital, Melbourne, Victoria, Australia
| | - Emily Jenkins
- Department of Anaesthesia, Austin Hospital, Melbourne, Victoria, Australia
| | - David McD Taylor
- Emergency Department, Austin Hospital, Melbourne, Victoria, Australia
| | - Glenn M Eastwood
- Department of Intensive Care, Austin Hospital, Melbourne, Victoria, Australia.,ANZIC Research Centre, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia.,Data Analytics Research and Evaluation Centre (DARE), Austin Hospital and The University of Melbourne, Melbourne, Victoria, Australia
| | - Rinaldo Bellomo
- Department of Intensive Care, Austin Hospital, Melbourne, Victoria, Australia.,ANZIC Research Centre, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia.,Data Analytics Research and Evaluation Centre (DARE), Austin Hospital and The University of Melbourne, Melbourne, Victoria, Australia.,Department of Medicine, The University of Melbourne, Melbourne, Victoria, Australia
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Eyeington CT, Ancona P, Cioccari L, Luethi N, Glassford NJ, Eastwood GM, Proimos HK, Franceschi F, Chan MJ, Jones D, Bellomo R. Non-Invasive Estimation of Cardiac Index in Healthy Volunteers. Anaesth Intensive Care 2018; 46:290-296. [DOI: 10.1177/0310057x1804600306] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The primary objective was to non-invasively measure the cardiac index (CI) and associated haemodynamic parameters of healthy volunteers and their changes with age. This was a single centre, prospective, observational study of healthy volunteers aged between 20 and 59 years, using the ClearSight™ (Edwards Life Sciences, Irvine, CA, USA) device. We recorded 514 observations in 97 participants. The mean CI was 3.5 l/min/m2 (95% confidence interval [95% CI] 3.4 to 3.7 l/min/m2). The mean stroke volume index (SVI) was 47 ml/m2 (95% CI 45 to 49 ml/m2) and the mean systemic vascular resistance index was 2,242 dyne·s/cm5/m2 (95% CI 2,124 to 2,365 dyne·s/cm5/m2). There was an inverse linear relationship between increasing age and CI (P <0.0001), which decreased by 0.044 l/min/m2 (95% CI −0.032 to −0.056 l/min/m2) per year. This change was mostly due to a decrease in SVI of 0.45 ml/m2 (95% CI 0.32 to 0.57 ml/m2) per year (P <0.0001). The mean CI of young healthy humans is approximately 3.5 l/min/m2 and declines by approximately 40 ml/min/m2 per year, mostly due to a decline in stroke volume (SV). These findings have significant implications regarding the clinical interpretation of haemodynamic parameters and the application of these results to individual patients.
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Affiliation(s)
- C. T. Eyeington
- Department of Intensive Care, Austin Hospital, Melbourne, Victoria
| | - P. Ancona
- Intensive Care, Austin Hospital, Melbourne, Victoria
| | - L. Cioccari
- Intensive Care, Austin Hospital, Melbourne, Victoria
| | - N. Luethi
- Intensive Care, Austin Hospital, Melbourne, Victoria
| | - N. J. Glassford
- Department of Anaesthesia, Austin Hospital; Australian and New Zealand Intensive Care Research Centre (ANZIC-RC), School of Public Health and Preventative Medicine, Monash University; Melbourne, Victoria
| | | | - H. K. Proimos
- Department of Intensive Care, Austin Hospital, Melbourne, Victoria
| | - F. Franceschi
- Department of Intensive Care, Austin Hospital, Melbourne, Victoria
| | - M. J. Chan
- Department of Intensive Care, Austin Hospital, Melbourne, Victoria
| | - D. Jones
- Consultant Intensivist, Associate Professor of Intensive Care, Department of Intensive Care, Austin Hospital; Australian and New Zealand Intensive Care Research Centre (ANZIC-RC), School of Public Health and Preventative Medicine, Monash University; Melbourne, Victoria
| | - R. Bellomo
- Consultant Intensivist, Professor of Intensive Care, Director of Intensive Care Research, Department of Intensive Care, Austin Hospital; Australian and New Zealand Intensive Care Research Centre (ANZIC-RC), School of Public Health and Preventative Medicine, Monash University; Department of Medicine, Melbourne University; Melbourne, Victoria
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Gastinger S, Sefati H, Nicolas G, Sorel A, Gratas-Delamarche A, Prioux J. Estimates of ventilation from measurements of rib cage and abdominal distances: a portable device. Eur J Appl Physiol 2010; 109:1179-89. [DOI: 10.1007/s00421-010-1463-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/25/2010] [Indexed: 11/30/2022]
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Lund-Johansen P. Hemodynamic trends in untreated essential hypertension. Preliminary report on a 10 year follow-up study. ACTA MEDICA SCANDINAVICA. SUPPLEMENTUM 2009; 602:68-76. [PMID: 1071954 DOI: 10.1111/j.0954-6820.1977.tb07648.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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5
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Lund-Johansen P. Haemodynamic changes in the elderly hypertensives. ACTA MEDICA SCANDINAVICA. SUPPLEMENTUM 2009; 676:86-102. [PMID: 6581694 DOI: 10.1111/j.0954-6820.1983.tb19335.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Lund-Johansen P. Hemodynamic alterations in hypertension--spontaneous changes and effects of drug therapy. A review. ACTA MEDICA SCANDINAVICA. SUPPLEMENTUM 2009; 603:1-14. [PMID: 325997 DOI: 10.1111/j.0954-6820.1977.tb19353.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Lund-Johansen P. Central haemodynamics in essential hypertension. ACTA MEDICA SCANDINAVICA. SUPPLEMENTUM 2009; 606:35-42. [PMID: 268932 DOI: 10.1111/j.0954-6820.1977.tb18027.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Khouri MG, Maurer MS, El-Khoury Rumbarger L. Assessment of age-related changes in left ventricular structure and function by freehand three-dimensional echocardiography. ACTA ACUST UNITED AC 2005; 14:118-25. [PMID: 15886537 DOI: 10.1111/j.1076-7460.2005.03845.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
To determine age-related changes in left ventricular (LV) structure and function, the authors used freehand three-dimensional echocardiography, a previously validated tomographic technique, to measure LV mass, volumes, and derived parameters in 94 sedentary, but ambulatory and clinically healthy, adult male and female volunteers aged 20-94. LV volumes and mass were significantly greater in men than in women (p<0.001) and remained greater after adjustment for body surface area and height (p<0.05). Declines in end-diastolic and stroke volumes with age were reduced or absent after accounting for body size. By multivariate analysis, age accounted for only about 6%-11% of the variance among LV volumes and mass, in comparison with body surface area and gender, which accounted jointly for about 46%-77% of the variance. In conclusion, changes occur in LV structure and function with normal aging, but these changes are relatively minor when body size and gender are taken into account.
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Affiliation(s)
- Michel G Khouri
- College of Physicians and Surgeons, Columbia University, New York, NY 11034, USA
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Slotwiner DJ, Devereux RB, Schwartz JE, Pickering TG, de Simone G, Ganau A, Saba PS, Roman MJ. Relation of age to left ventricular function in clinically normal adults. Am J Cardiol 1998; 82:621-6. [PMID: 9732891 DOI: 10.1016/s0002-9149(98)00390-7] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The extent to which age, independent of cardiovascular diseases, influences left ventricular (LV) function in adults is uncertain. Echocardiograms and simultaneous arterial pressure in 464 clinically normal adults aged 16 to 88 years were used to measure LV dimensions, endocardial and midwall LV fractional shortening, stroke volume, cardiac output, and circumferential end-systolic stress. The ratios of observed endocardial and midwall shortening to values predicted for observed end-systolic stress were used as measures of chamber and myocardial function. LV endocardial shortening increased slightly with age, as did an index of LV chamber performance, the end-systolic stress/volume index ratio (r = 0.11, p = 0.019, and r = 0.20, p <0.001). However, when age-related increases in LV wall thickness and blood pressure were controlled for by examining afterload-corrected endocardial shortening, no age relation was detected. Weak age-related declines were observed in midwall shortening (r = -0.09, p = 0.043) and afterload-corrected midwall shortening (r = -0.12, p <0.01). Cardiac index decreased slightly with advancing age (r = -0.14, mean -6.7 ml/min/m2/ year, p = 0.003). Total peripheral resistance and the pulse pressure/stroke volume ratio, a measure of arterial stiffness, increased more strongly with age (r = 0.27 and 0.38, both p <0.001). Thus, LV pump performance at rest measured by cardiac index is slightly lower in older than in younger clinically normal adults. Endocardial fractional shortening was slightly higher in older subjects, but the physiologically more appropriate midwall measures of myocardial function decreased slightly. The observed change in LV pump performance was related to smaller LV chamber size and higher total peripheral resistance in older subjects.
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Affiliation(s)
- D J Slotwiner
- Department of Medicine and Hypertension Center, The New York Hospital-Cornell Medical Center, New York 10021, USA
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Fabre C, Chamari K, Anselme-Poujol F, Préfaut C. Réponses cardiorespiratoires à l'exercice chez des cyclistes très entraînés: effets du vieillissement. Sci Sports 1994. [DOI: 10.1016/s0765-1597(05)80066-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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11
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Gómez-Terreros Sánchez F, Puerro Vicente M, Caro de Miguel M, Callol Sánchez L, Calderón Álvarez J. El pulso de oxígeno en el pequeño esfuerzo. Aproximación a su significado. Arch Bronconeumol 1991. [DOI: 10.1016/s0300-2896(15)31534-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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12
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Danziger RS, Tobin JD, Becker LC, Lakatta EE, Fleg JL. The age-associated decline in glomerular filtration in healthy normotensive volunteers. Lack of relationship to cardiovascular performance. J Am Geriatr Soc 1990; 38:1127-32. [PMID: 2229867 DOI: 10.1111/j.1532-5415.1990.tb01376.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Whether the well-documented age-associated decline in the glomerular filtration rate, manifest as a decline in creatinine clearance, is secondary to an age-related change in cardiovascular performance is at present unknown. To answer this question, we measured arterial blood pressure, 24-hour creatinine clearance, and cardiac output determined from gated cardiac blood pool scans in the sitting position in healthy normotensive men (n = 75) and women (n = 42) (ages 25 to 82 years), from the Baltimore Longitudinal Study on Aging. These subjects were selected for the absence of cardiovascular disease, renal disease, and confounding medications. By linear regression analysis, creatinine clearance, expressed in mL/min/m2, declined cross-sectionally with age (creatinine clearance = 90 -0.33[age], r = .31, P less than .001), whereas systolic blood pressure in mm Hg increased with age (systolic blood pressure = 111 + 0.27[age], r = .30, P less than .001); cardiac output in L/min/m2 did not vary with age (r = .03, P = .74). In stepwise multiple regression analysis with age, cardiac index, and systolic blood pressure as independent variables and creatinine clearance as the dependent variable, only age was a significant predictor of creatinine clearance. (F = 11.31, DF + 116, r = .30, P less than .001). Thus, the age-associated decline in creatinine clearance is not modulated by changes in cardiac index or systolic blood pressure in healthy normotensive subjects.
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Affiliation(s)
- R S Danziger
- Laboratory of Cardiovascular Science, National Institute on Aging, Baltimore, Maryland 21224
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Higginbotham MB, Morris KG, Williams RS, Coleman RE, Cobb FR. Physiologic basis for the age-related decline in aerobic work capacity. Am J Cardiol 1986; 57:1374-9. [PMID: 3717040 DOI: 10.1016/0002-9149(86)90221-3] [Citation(s) in RCA: 85] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
To determine the physiologic mechanisms of the decline in aerobic work performance with age, a cross-sectional study was performed. Twenty-four sedentary male volunteers, aged 20 to 50 years, underwent right-sided cardiac catheterization, arterial cannulation, radionuclide angiography and expired gas analysis for detailed evaluation of central and peripheral cardiovascular function during submaximal and maximal exercise. Habitual physical activity level varied but was well matched across the age range. Over the 3-decade age range studied, there was no detectable change in cardiovascular function at rest. When peak exercise variables were examined, an age-related 25% decrease in O2 consumption was noted (r = -0.43, p = 0.04); this was associated with a 25% decrease in peak cardiac index (r = -0.54, p = 0.01) and a 20% decrease in peak heart rate (r = -0.63, p = 0.002). In addition, there was an age-related increase in calculated systemic and pulmonary vascular resistances and an increase in left ventricular ejection time. No age relation was seen for exercise stroke volume index, end-diastolic volume index, end-systolic volume index, pulmonary artery wedge pressure, ejection fraction or arteriovenous O2 difference. These results indicate that the age-related decline in aerobic work performance among men aged 20 to 50 years results primarily from a reduced exercise heart rate in older subjects rather than from a reduction in stroke volume or peripheral O2 utilization.
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Abstract
The determinants of endurance effort vary, depending upon the extent of the muscle mass that is activated. Large muscle work, such as treadmill running, is halted by impending circulatory failure; lack of venous return may compound the basic problem of an excessive cardiac work-load. If the task calls for use of a smaller muscle mass, there is ultimately difficulty in perfusing the active muscles, and glycolysis is halted by an accumulation of acid metabolites. Simple field tests of endurance, such as Cooper's 12-minute run and the Canadian Home Fitness Test, have some value in the rapid screening of large populations, but like other submaximal tests of human performance they lack the precision needed to advise the individual. The directly measured maximum oxygen intake (VO2 max) varies with the type of exercise. The highest values are obtained during uphill treadmill running, but well trained athletes often approach these values during performance of sport-specific tasks. Limitations of methodology and wide interindividual variations of constitutional potential limit the interpretation of maximum oxygen intake data in terms of personal fitness, exercise prescription and the monitoring of training responses. The main practical value of VO2 max measurement is in the functional assessment of patients with cardiorespiratory disease, since changes are then large relative to the precision of the test.
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Skagen K, Haxholdt O, Henriksen O, Dyrberg V. Effect of spinal sympathetic blockade upon postural changes of blood flow in human peripheral tissues. ACTA PHYSIOLOGICA SCANDINAVICA 1982; 114:165-70. [PMID: 7136753 DOI: 10.1111/j.1748-1716.1982.tb06968.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The effect of head-up tilt upon subcutaneous and skeletal muscle blood flow in the crus was studied before and during epidural blockade in 10 subjects. Relative changes in blood flow were estimated by the local 133Xe washout technique. In subcutaneous tissue head-up tilt induced a decrease in blood flow of about 40% and there was no difference in the vascular response to head-up tilt before and during epidural blockade. In skeletal muscle tissue essentially the same was found as head-up tilt decreased blood flow by about 26% the response being uninfluenced by epidural blockade. In 3 patients local nervous blockade was induced by Lidocaine in 133Xe labelled subcutaneous tissue on one side. During epidural blockade and tilt blood flow increased by 12% whereas blood flow decreased by 30% on the control side. Thus epidural blockade had no influence on the vasoconstrictor response in subcutaneous tissue and skeletal muscle to head-up tilt whereas local blockade was able to prevent the response. Local mechanisms including the local veno-arteriolar reflex appear to play an important role for the observed maintenance of arterial blood pressure in the tilted position during central sympathetic blockade.
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Skagen K, Bonde-Petersen F. Regulation of subcutaneous blood flow during head-up tilt (45 degrees) in normals. ACTA PHYSIOLOGICA SCANDINAVICA 1982; 114:31-5. [PMID: 7136743 DOI: 10.1111/j.1748-1716.1982.tb06948.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Local and remote regulation of subcutaneous blood flow in the forearm and leg was studied during head-up tilt (45 degrees) in 6 young healthy male subjects. Relative blood flow was estimated by the local 133Xe washout technique. Lowering of a leg to a 51% decrease in its subcutaneous blood flow due to a veno-arteriolar reflex elicited by the increase in venous transmural pressure. During head-up tilt subcutaneous blood flow in the arm remaining at heart level decreased by 27%, in the leg blood flow decreased by 50%. Following proximal nervous blockade, head-up tilt did not induce vasoconstriction in forearm at heart level, but blood flow in distal leg decreased by 45%. Thus there was no difference in the vasoconstrictor response in the leg to head-up tilt or lowering of the labelled area by 40 cm. Since head-up tilt caused neurogenically mediated vasoconstriction in subcutaneous tissue, subcutaneous blood flow in the extremities seems to be regulated by remote (baroreceptor) as well as local sympathetic reflex mechanisms (veno-arteriolar reflex).
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Hossack KF, Bruce RA, Green B, Kusumi F, DeRouen TA, Trimble S. Maximal cardiac output during upright exercise: approximate normal standards and variations with coronary heart disease. Am J Cardiol 1980; 46:204-12. [PMID: 7405834 DOI: 10.1016/0002-9149(80)90059-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Henriksen O, Sejrsen P. Local reflex in microcirculation in human skeletal muscle. ACTA PHYSIOLOGICA SCANDINAVICA 1977; 99:19-26. [PMID: 842361 DOI: 10.1111/j.1748-1716.1977.tb10347.x] [Citation(s) in RCA: 115] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The effect of venous stasis of 40 mmHg upon blood flow in human skeletal muscle was studied in four normal subjects and in two chronically sympathectomized patients. Blood flow in skeletal muscle was measured by the local 133Xenon washout technique. Blood flow decreased about 30 per cent during venous stasis of 40 mmHg. In a "passive vascular bed" induced by means of histamine, blood flow decreased only by 16 per cent, indicating that the decrease in blood flow is due to a vasoconstrictor response to increase in vascular transmural pressure. The vasoconstrictor response was unaffected by a spinal sympathetic blockade, but was blocked in areas infiltrated with lidocaine or with phentolamine. The vasoconstrictor response was present in the nonoperated limbs used as a control, but abolished in the denervated arms in the two chronically sympathectomized patients. The findings strongly suggest that the vasoconstrictor response in skeletal muscle is due to a local nervous mechanism involving adrenergic fibres. Thus a local reflex mechanism, most likely a sympathetic axon reflex, seems to be present in human skeletal muscle as in cutaneous and subcutaneous tissue. This indicates that about 45 per cent of the change in total vascular conductance, when a person changes from supine to upright position, is due to this local reflex mechanism operating independently of the central nervous system.
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Ogilvie RI. Cardiovascular response to exercise under increasing doses of chlorthalidone. Eur J Clin Pharmacol 1976; 09:339-44. [PMID: 9291 DOI: 10.1007/bf00606546] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Five male subjects with essential hypertension received chlorthalidone at each of four dose levels (25, 50, 100, and 200 mg/day) for eight week periods each preceded by an eight week placebo period. Dosage order was randomized and double-blind. During the last week of each active and placebo period an upright bicycle exercise study was carried out at three loads (100, 200, 300 kpm/min) for 6 min each. Oxygen consumption at the maximal workload was 42% of predicted at a heart rate of 170. During placebo therapy, increasing workloads were associated with a progressive increase in blood pressure, heart rate, and pressure-rate index (systolic pressure times heart rate). With increasing doses of chlorthalidone up to 100 mg/day, there was a progressive reduction in blood pressure and pressure-rate index. At 200 mg/day there were paradoxical increases in diastolic pressures, heart rates and pressure-rate indices above values observed at 100 mg/day. With increasing doses of chlorthalidone, there was a progressive increase in arterial blood CO2 content and pH. Increasing workloads were associated with increased arterial blood lactate and decreased arterial blood lactate and decreased arterial blood pH. The changes in lactate and pH were not different at the different dose levels. The best antihypertensive effect in these exercising subjects was observed at a daily dose of 100 mg of chlorthalidone. The exercise response was useful in the determination of potentially adverse hemodynamic consequences of the larger dose of chlorthalidone.
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Griepp RB, Stinson EB, Oyer PE, Copeland JG, Shumway NE. The superiority of aortic cross-clamping with profound local hypothermia for myocardial protection during aorta-coronary bypass grafting. J Thorac Cardiovasc Surg 1975. [DOI: 10.1016/s0022-5223(19)39648-5] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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McDonough JR, Danielson RA, Wills RE, Vine DL. Maximal cardiac output during exercise in patients with coronary artery disease. Am J Cardiol 1974; 33:23-9. [PMID: 4202449 DOI: 10.1016/0002-9149(74)90735-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Corbett JL, Harris PJ. Studies on the sympathetic nervous system in tetanus. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 1973; 276:447-60. [PMID: 4268171 DOI: 10.1007/bf00499897] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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