The Effect of Exercise on Coronary Blood Flow, Myocardial Oxygen Consumption and Cardiac Efficiency in Man

Lombardo, Thomas A.; Rose, Leonard B.; Taeschler, M; Tuluy, S.; Bing, Richard J.

doi:10.1161/01.cir.7.1.71

Cited by 103 publications

(34 citation statements)

References 23 publications

(2 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…scatter of values than that described herein has been reported in the 12 patients with various cardiac disorders of Lombardo and associates (5) and in the 9 control subjects of Regan and colleagues (6). Their average rest-exercise myocardial oxygen extraction changes were + 3 and + 2 per cent, respectively.…”

Section: Clinical-physiological Correlationssupporting

confidence: 48%

Patterns of Human Myocardial Oxygen Extraction During Rest and Exercise*

Messer¹,

Wagman²,

Levine³

et al. 1962

J. Clin. Invest.

123

View full text Add to dashboard Cite

Myocardial oxygen requirements are met by coronary blood flow and oxygen extraction from the arterial blood. The myocardial oxygen extraction coefficient (1) expresses the fraction of available oxygen in arterial blood removed by the myocardium: coronary A-Vo2/Ao2 X 100 = myocardial extraction percentage. Myocardial oxygen extraction during rest is approximately 70 to 75 per cent, exceeding that of all other organs (1, 2). This degree of extraction is equalled only by exercising skeletal muscle, in which increased oxygen requirements are met both by additional blood flow and by increased oxygen extraction. Earlier workers have noted a relative constancy of myocardial oxygen extraction under the widely varying conditions of rest, anemia, hypoxia, and increased left ventricular work, suggesting that coronary blood flow is altered commensurate with myocardial oxygen requirements (1, 3, 4). Case, Berglund and Sarnoff demonstrated that when coronary blood flow reserve was limited by experimental coronary constriction, myocardial extraction increased due to the combined stress of anemia and increased left ventricular work (3).The effect of exercise on coronary hemodynamics has received little attention. Lombardo and co-workers reported observations in 13 human subjects with various forms of heart disease (5). As part of another study, Regan and associates reported on the effects of exercise on the coronary circulation in nine normal subjects (6). This report will present myocardial oxygen extraction data from 108 patients at rest, and from 79 subjects during mild exercise. The physiological significance of myocardial oxygen extrac-* This work was supported by grants from the U. S. (7), and routine cardiac catheterization findings. The exercise electrocardiograms were interpreted according to the criteria of Mattingly, Fancher, Bauer and Robb (8).Four clinical states were selected for correlation with myocardial oxygen extraction patterns. The patients were grouped clinically according to the following criteria.Control. Patients having no symptoms or electrocardiographic, radiologic or physical findings suggesting coronary artery disease or congestive heart failure served as controls. Pulmonary capillary pressures were normal in all subjects except those with mild mitral stenosis. The range of diagnoses included functional systolic murmurs, patent ductus arteriosus, ventricular and atrial septal defects, mild aortic insufficiency, noncritical mitral stenosis (valve area greater than 1.5 cm'), tetralogy of Fallot, and mild coarctation of the aorta. Two had atypical chest pain without evidence to suggest coronary insufficiency.Coronary insufficiency. Patients judged to have coronary insufficiency on the basis of classical angina pectoris, documented myocardial infarction, and positive Master's test were placed in this group. In several cases the coronary vessels were assessed at operation, by coronary arteriography (9), or at necropsy. Several patients had coexisting congestive heart failure.Congestive heart failure. Th...

show abstract

Section: Clinical-physiological Correlationssupporting

confidence: 48%

Patterns of Human Myocardial Oxygen Extraction During Rest and Exercise*

Messer¹,

Wagman²,

Levine³

et al. 1962

J. Clin. Invest.

123

View full text Add to dashboard Cite

show abstract

“…The general hemodynamic and myocardial blood flow responses to exercise are detailed in Table I for the fasting normal subjects and in Table II gen extraction during exercise and the level at rest has not been found (16). A greater increment has actually been observed in patients with resting extractions above 11.0 vol per cent than in those below.…”

Section: Resultsmentioning

confidence: 99%

“…A fourfold enhancement of left ventricular mechanical efficiency has been observed during intravascular volume expansion without evidence of a significant oxygen debt (25). There is also some indication that in high output states estimated efficiency during exercise may as much as double without evidence of cardiac dysfunction (16 Despite these findings, the mechanical performance of the heart was normal and lipemia was associated with no evidence of myocardial ischemia, as judged by lactate extractions. The possibility is considered that this lipemic effect on myocardial blood flow and oxygen consumption during exercise may occur at low plasma lactescence levels following a more usual meal.…”

Section: Discussionmentioning

confidence: 99%

Myocardial Oxygen Consumption During Exercise in Fasting and Lipemic Subjects*

Regan¹,

Timmis²,

Gray³

et al. 1961

J. Clin. Invest.

View full text Add to dashboard Cite

“…Although the transcapillary exchange rates of an ion, such as potassium, are blood flow dependent (8), an estimation of the effects of altered blood flow per se upon measured arteriovenous differences appeared in order. In the intact human, two procedures which usually increase coronary blood flow, exercise (9) and hypoxia (10), were chosen to study coronary arteriovenous differences of potassium. Five minutes of exercise produced no significant change in six patients.…”

Section: Methodsmentioning

confidence: 99%

Myocardial Response to Acetyl Strophanthidin in Congestive Heart Failure: A Study of Electrolytes and Carbohydrate Substrates*

Regan¹,

Christensen²,

Wada³

et al. 1959

J. Clin. Invest.

View full text Add to dashboard Cite

The concept of a defect in the conversion of chemical energy to work as the cause of low output heart failure has been based on the finding of normal myocardial extraction of substrate and oxygen in this clinical state (1, 2). However, the alternative view, that there is failure in transformation of the energy of substrate oxidations to a biologically useful form, cannot be excluded (3). Of particular interest, as regards the former theory, is the problem of evaluating those physical-chemical factors which initiate or contribute to the alteration of myocardial protein in heart failure.A consideration of the role of changes in intracellular ionic content in the regulation of cardiac performance has been stimulated by finding an intimate relation between these parameters in the staircase phenomenon (4). Other isolated muscle work has shown that changes in electrolyte concentration at the superficial level of the cell can affect contractile strength of muscle before the ion penetrates the interior of the muscle (5, 6).Although there is at present no adequate methodology for precise study of these phenomena in the human heart in vivo, it was considered of im-.portance to seek information concerning the myo- (1954)(1955)(1956).:Public Health Trainee of the National Heart Institute (1955)(1956). § Research Fellow, R. C. Mahon Foundation (1956)(1957). Public Health Research Fellow of the National HeartInstitute (1953)(1954)(1955).of drug-induced recovery from cardiac failure. In a prior report (7), data were presented which indicated the facility with which acetyl strophanthidin mobilized electrolytes in the myocardium of the intact dog, its abrupt course of action enabling detection of these changes. METHODSThe design of this study was such as to rely on the assumption that the coronary arteriovenous differences of electrolytes and metabolites could be validly accepted as a measure of their net uptake by, or release from, the myocardium. Although the transcapillary exchange rates of an ion, such as potassium, are blood flow dependent (8), an estimation of the effects of altered blood flow per se upon measured arteriovenous differences appeared in order. In the intact human, two procedures which usually increase coronary blood flow, exercise (9) and hypoxia (10), were chosen to study coronary arteriovenous differences of potassium. Five minutes of exercise produced no significant change in six patients. The mean of the planimetered A-V difference areas for potassium was + 0.01 + 0.08 square inches in the control and + 0.06+ 0.20 in the experimental period. Similar results were obtained with hypoxia, induced by 10 per cent oxygen inhalation for 25 minutes in five patients.The mean control value was + 0.06 + 0.25 square inch and the hypoxia value, + 0.27 ± 0.23. These findings are in agreement with those of Driscol and Berne (11), in which coronary blood in the dog was increased up to 100 per cent by varied procedures without significant change in the potassium arteriovenous differences.The effects of digitalis preparat...

show abstract

The Effect of Exercise on Coronary Blood Flow, Myocardial Oxygen Consumption and Cardiac Efficiency in Man

Cited by 103 publications

References 23 publications

Patterns of Human Myocardial Oxygen Extraction During Rest and Exercise*

Patterns of Human Myocardial Oxygen Extraction During Rest and Exercise*

Myocardial Oxygen Consumption During Exercise in Fasting and Lipemic Subjects*

Myocardial Response to Acetyl Strophanthidin in Congestive Heart Failure: A Study of Electrolytes and Carbohydrate Substrates*

Contact Info

Product

Resources

About