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Biomedical subjects

H Kelbaek

Publications and source records attributed to H Kelbaek.

At least 73 records · Page 4Linked to original sources
PubMed1989

Intrinsic heart function and food intake.

The author reviews the haemodynamic changes in response to exercise, autonomic nervous blockade and food take, Left ventricular (LV) volume changes are most pronounced during mild exercise, whereas an increase in heart rate is the primary determinant for the increase in cardiac output during mild to heavy exercise. After autonomic blockage the heart possesses intrinsic mechanisms to maintain cardiac output during submaximal exercise. LV end-diastolic dilatation results in a preserved stroke volume despite reduced contractility. At rest cardiac output increase postprandially mostly because of a greater stroke volume accomplished by LV end diastolic dilatation, whereas heart rate is only slightly increased. These changes are unique to humans, and are thought to take place secondary to the action of vasoactive peptides from the gastrointestinal tract involved in digestion. The LV volume changes are minimized after autonomic nervous blockade. During exercise cardiac output in also higher after food intake due to a rise in both stroke volume and heart rate, but only in the innervated heart. Thus, most of the haemodynamic changes recorded after food intake are under the influence of the autonomic nervous system.

Autonomic Nervous System↗
PubMed1988

Impaired aerobic work capacity in insulin dependent diabetics with increased urinary albumin excretion.

To assess whether decreased aerobic work capacity was associated with albuminuria in insulin dependent diabetics aerobic capacity was measured in three groups of 10 patients matched for age, sex, duration of diabetes, and degree of physical activity. Group 1 comprised 10 patients with normal urinary albumin excretion (less than 30 mg/24 h), group 2 comprised 10 with incipient diabetic nephropathy (urinary albumin excretion 30-300 mg/24 h, and group 3 comprised 10 with clinical diabetic nephropathy (urinary albumin excretion greater than 300 mg/24 h). Ten non-diabetic subjects matched for sex, age, and physical activity served as controls. Oxygen uptake was similar in the four groups at rest and during a 75 W workload. Maximal oxygen uptake was also similar in the control subjects and group 1 (median 41.7, (range 29.1-53.0) ml/kg/min v 38.5 (26.6-59.2) ml/kg/min, respectively), but was significantly lower in group 2 (27.7 (13.9-44.3) ml/kg/min) and group 3 (22.6-36.7) ml/kg/min). The difference in maximal oxygen uptake between groups 1 and 2 was 10.8 ml/kg/min (95% confidence interval 3.6 to 23.4 ml/kg/min) and between groups 1 and 3, 11.7 ml/kg/min (4.9 to 22.5 ml/kg/min). These differences were not explained by differences in metabolic control or the degree of autonomic neuropathy. Thus the insulin dependent diabetics with only slightly increased urinary albumin excretion had an appreciably impaired aerobic work capacity which could not be explained by autonomic neuropathy or the duration of diabetes. Whether the reduced capacity is due to widespread microangiopathy or another pathological process affecting the myocardium remains to be established.

Adolescent↗
PubMed1988

Hemodynamic effects of alcohol at rest and during upright exercise in coronary artery disease.

The hemodynamic effects of acute alcohol intoxication were studied at rest and during upright exercise in 28 patients with coronary artery disease by right-sided heart catheterization and radionuclide cardiography. The mean arterial blood pressure at rest was reduced by 5% and the left ventricular ejection fraction at rest decreased 2% because of end-systolic dilation during intoxication (serum ethanol 21 mmol/liter). No changes were observed in heart rate, stroke volume, pulmonary artery pressure, pulmonary artery wedge pressure or total peripheral resistance. No significant changes occurred in plasma catecholamines, and no changes occurred in any variable during mild exercise corresponding to a 30 to 40% heart rate increase. Thus, alcohol ingested in moderate doses causes slight impairment of left ventricular emptying and a reduction in the arterial blood pressure at rest in patients with coronary artery disease. A mild exercise load can be tolerated during alcohol intoxication without hemodynamic changes.

Aged↗
PubMed1988

Evaluation of a new leukocyte labeling procedure with 99mTc-HMPAO.

A technique for labeling leukocytes with 99mTc using hexamethylpropylene-amineoxime (HMPAO) was evaluated in vitro. The labeling procedure resulted in a cell bound fraction of radioactivity of 56% after 99mTc incubation and 96% after 1 washing of cells. In the final cell suspension 84% of the radioactivity was attached to the polymorphonuclear (PMN) leukocytes constituting 94% of white cells. Only 5% was bound to residual red blood cells. The stability evaluated in autologous plasma showed a decline of cell bound activity from 96% to 84% over 3 h. The chemotactic function of PMN leukocytes was unaffected by the labeling procedure. These findings demonstrate that HMPAO, albeit cell unspecific, is efficient for labeling PMN leukocytes with 99mTc. The stability of the labeling procedure is high and the technique does not affect cell function. No other current 99mTc leukocyte labeling technique possesses all these qualities.

Evaluation Studies as Topic↗
PubMed1988

Cardiac function at rest and during exercise in early and late alcohol intoxication.

Seven healthy men, aged 21 to 30 years, were investigated by radionuclide cardiography at rest and during submaximal exercise at heavy (early) and during declining (late) alcohol intoxication. Control studies, in which alcohol was substituted by an isocaloric, isovolumic drink, were performed on a different day. The left ventricular ejection fraction at rest decreased from 59 to 56% during early intoxication (serum ethanol 35 +/- 6 mmol/l), whereas no change was observed in the ejection fraction during exercise. No significant change was recorded in stroke volume after alcohol consumption as opposed to a small increase after ingestion of the caloric drink. Plasma noradrenaline concentrations were elevated during exercise and early intoxication. During late intoxication (serum ethanol 21 +/- 5 mmol/l) the left ventricular ejection fraction at rest was increased by 7% compared with the baseline value. At rest the heart rate was increased from 68 +/- 7 to 84 +/- 15 beats/min, whereas cardiac output had reverted to the baseline value. Plasma noradrenaline at late intoxication was increased both at rest and during exercise compared with the baseline values. Apart from tachycardia and a reduction in left ventricular volumes during late intoxication no alcohol induced hemodynamic changes occurred during exercise.

Adult↗
PubMed1988

Combined first pass and equilibrium radionuclide cardiographic determination of stroke volume for quantitation of valvular regurgitation.

A new noninvasive procedure for quantitation of cardiac valve regurgitation was evaluated using a combination of first pass and gated equilibrium radionuclide cardiography in 38 subjects with and without cardiac valve disease. Left-sided cardiac catheterization was performed to determine the severity of mitral incompetence and aortic regurgitation semiquantitatively. In healthy subjects and in patients without valve disease, stroke volumes were nearly identical with the two methods and the correlation was high (r = 0.98 [p less than 0.001]). The mean regurgitation fraction was 13% in patients with mild mitral incompetence and 2+ aortic regurgitation, 37% in patients with moderate mitral incompetence and 3+ aortic regurgitation and 57% in patients with severe mitral incompetence and 4+ aortic regurgitation. These findings suggest that combined first pass and gated equilibrium radionuclide cardiography, being insensitive to intracardiac shunts and right-sided valve disorders, constitutes a valid noninvasive technique for quantitation of left-sided cardiac valve regurgitation.

Adult↗
PubMed1988

Coronary and skeletal muscle enzyme changes during a 14 km run.

Increasing coronary enzyme values have previously been demonstrated after physical exercise. In the present study serum values of aspartate aminotransferase (ASAT), lactate dehydrogenase (LDH), LDH isoenzymes, creatinine kinase (CK), and the myocardial-bound fraction of this enzyme (CK-MB) were measured in a random sample of healthy non-smoking, physically fit men before and immediately after a competitional 14 km run. All enzyme values increased during the run, ASAT by 7%, LDH by 25%, CK by 38%, and CK-MB by 53%. Measurement of LDH isoenzymes showed special increments of the non-cardiac fractions. However, absolute increments of the cardiac fractions of the LDH isoenzymes together with other serum enzyme elevations do not exclude a cardiac source of enzyme release during and following physical exercise.

Adult↗
PubMed1988

Left ventricular volumes during graded upright exercise in healthy untrained subjects.

Left ventricular (LV) volume changes were studied by radionuclide cardiography at rest and during graded upright bicycle exercise in seven healthy untrained men aged 21-30 years. The exercise-induced changes in LV volumes were most pronounced during mild exercise: from rest to 25% submaximal exercise stroke volume increased by 26% and LV ejection fraction from 0.60 to 0.69 (both P less than 0.01), whereas further increments of the work load resulted in only small changes of these variables. LV end-diastolic volume increased initially by 10% (P less than 0.05) but returned to baseline values at higher work loads, whilst a rather constant decrease was recorded in LV end-systolic volume during increasing exercise loads. Changes in plasma catecholamine levels were most pronounced at the high work loads, indicating that these hormones are not directly contributing to the LV volume changes.

Adult↗
PubMed1988

Central and peripheral haemodynamic changes after alcohol ingestion.

Central and peripheral haemodynamic changes 1 and 8 hours after alcohol ingestion were studied in seven healthy men, aged 21-30 years, by radionuclide cardiography and strain gauge plethysmography. Heart rate (HR) increased by 12% and cardiac output (CO) by 24% 1 hour after alcohol ingestion (mean serum ethanol 35 mmol/l). Left ventricular (LV) ejection fraction (EF) decreased by 5% because of endsystolic dilation and the forearm blood flow increased by 140%. Eight hours after alcohol ingestion (serum ethanol 21 mmol/l.) hangover symptoms were present in all subjects. HR and CO remained increased by 19% and 23%, respectively. A 4% increase was recorded in LVEF. The total peripheral resistance was reduced by 25%, while the forearm blood flow had returned to baseline values. No significant changes in plasma catecholamines were recorded. Apart from a slight increase in CO at 1 hour no haemodynamic changes were recorded after ingestion of an isovolumic, isocaloric drink. The present findings suggest that acute alcohol intoxication causes impairment of LV contractility, but that tachycardia results in an increase in cardiac output accompanied by an increased blood flow in the forearm. In the early hangover phase, when the serum ethanol is still elevated, cardiac output remains enhanced because of tachycardia, although the sympathetic nervous activity as measured by the plasma norepinephrine level is not influenced. A reduced total peripheral resistance may contribute to the increase in LV contractility in spite of sustained alcohol intoxication.

Adult↗
PubMed1988

Thallium-201 myocardial scintigraphy during dipyridamole-induced coronary hyperaemia. First experiences with a new regional washout programme.

Eight patients with severe peripheral vascular atherosclerosis scheduled for abdominal aortic surgery were investigated to detect coexisting coronary artery disease. None of the patients had a history of angina pectoris or previous myocardial infarction. Preoperative computerised thallium-201 dipyridamole myocardial scintigraphy was abnormal in all patients, showing either myocardial scar tissue and/or ischaemia with redistribution and/or low washout. In all but one patient, the serum level of creatin kinase was elevated during the first postoperative days. In two patients, the serum concentrations of aspartate aminotransferase and lactate dehydrogenase were elevated. None of the patients showed clinical or electrocardiographical signs of acute myocardial infarction. Thallium-201 dipyridamole myocardial imaging is a new noninvasive method for detection of ischaemic heart disease in patients with severe peripheral atherosclerosis who are unable to perform a bicycle exercise test. The new programme for determination of regional washout appeared to be very precise and may be especially applicable in the case of low washout values.

Aged↗
PubMed1988

Cardiac function after alcohol ingestion in patients with ischemic heart disease and cardiomyopathy: a controlled study.

Thirty male patients with ischemic heart disease and cardiomyopathy entered a controlled study of the acute effects of alcohol on cardiac function evaluated by right heart catheterization. Twenty patients, nine with angina pectoris and 11 with congestive heart failure, were studied during alcohol intoxication, and ten patients, five with angina pectoris and five with heart failure, served as a control group. The mean serum ethanol concentration in the alcohol group was 93 mg/100 ml (S.D. 17). The systemic arterial blood pressure was reduced by 6% in the alcohol group, P less than 0.05 compared with the control group. No significant changes occurred in the central venous pressure, the pulmonary artery pressure, the pulmonary capillary wedge pressure, or in cardiac output, stroke volume and total peripheral resistance. Alcohol intake in moderate doses has no measurable effect on pulmonary blood pressures or cardiac output in patients with ischemic heart disease and cardiomyopathy. Such an effect may, however, be masked by a reduction of afterload.

Aged↗
PubMed1987

Left ventricular function during alcohol intoxication and autonomic nervous blockade.

Eight healthy young subjects (6 men, 2 women) entered a controlled investigation of left ventricular (LV) function during alcohol intoxication and autonomic nervous blockade. Radionuclide cardiography was performed at rest and during upright 50% submaximal bicycle exercise. During alcohol intoxication alone (serum ethanol 30 mmol/liter), heart rate at rest increased by 11% (p less than 0.05) and LV ejection fraction (EF) decreased by 6% because of end-systolic dilation. No significant alcohol-induced hemodynamic changes were observed during exercise. Plasma norepinephrine concentration increased by 29% (p less than 0.05), whereas plasma epinephrine concentration did not change. During subsequent autonomic nervous blockade with intravenous metoprolol and atropine infusion, heart rate at rest further increased and systolic blood pressure decreased. These changes were not, however, significantly different from those of a control experiment in which a nonalcoholic isocaloric drink was substituted for alcohol. Plasma norepinephrine levels at rest and during exercise were 25% and 32% higher (both p less than 0.05), respectively, than those during control conditions. Plasma epinephrine concentrations did not change. These findings suggest that alcohol intoxication has a depressant effect on LV function at rest that stimulates autonomic nervous blockade. The increased sympathetic nervous activity during exercise appears to be a toxic rather than a compensatory effect of alcohol.

Adult↗
PubMed1987

Evaluation of radiocardiographic methods for determination of cardiac output and right and left ventricular ejection fractions using a cardiac phantom.

Cardiac output and ejection fractions of the cardiac ventricles are valuable measures of cardiac function. Noninvasive radionuclide techniques for determination of these measures are based on analysis of different data: first passage low frequency, first passage high frequency and multigated equilibrium data. We have evaluated the principles of these methods using a dynamic cardiac phantom. Radiocardiographic determinations of cardiac output and right and left ventricular ejection fractions showed excellent correlation against true phantom values: r = 0.993 (p less than 0.001), r = 0.978 (p less than 0.01) and r = 0.943 (p less than 0.05), respectively. Thus, the findings of the present study demonstrate a high validity of current radiocardiographic measures of cardiac function.

Cardiac Output↗
PubMed1987

Haemodynamic response to exercise in patients with alcoholic liver cirrhosis.

Physical work capacity was evaluated by a multistage bicycle exercise test in 29 patients, 22 men and seven women aged 35-61 years (mean 49) with alcoholic liver cirrhosis and in a sex- and age-matched control group. The maximal work load was reduced in the patient group, mean 122 vs. 186 watts in men (P less than 0.001), and 60 vs. 119 watts in women (P less than 0.005). Resting heart rate was higher in patients (91 vs. 78 beats X min-1, P less than 0.005), and the maximal heart rate was lower (159 vs. 170 beats X min-1, P less than 0.001) compared with controls. Thirteen of 29 (45%) patients compared with 5 of 29 (17%) control subjects had an increase in left ventricular ejection fraction of less than or equal to 5% during exercise (P less than 0.05). The present results suggest that an impaired capacity of the cardiac function to respond adequately to physical stress may at times contribute to the reduced physical work capacity seen in patients with alcoholic liver cirrhosis.

Adult↗
PubMed1987

Left ventricular performance in alcoholic patients without chronic liver disease.

Left ventricular performance was studied non-invasively in 24 chronic alcoholics without liver disease. Twelve patients who had abstained from drinking for at least one month (group A) and 12 sex and age matched patients who had ceased drinking during the preceding 24 hours (group B) were studied at rest and during 50% submaximal exercise. Cardiac output and stroke volume were measured by first passage and left ventricular ejection fraction by multigated radionuclide cardiography. Twelve healthy sex and age matched controls were also studied. Haemodynamic variables were similar in group A and the controls, except that in group A left ventricular end systolic volume index did not decrease during exercise. In group B the heart rate was increased both at rest and during exercise and plasma noradrenaline concentrations were increased. The stroke volume index did not increase significantly during exercise in group B. In addition, the increase in left ventricular ejection fraction was smaller in group B than in controls. End systolic contraction was reduced in group B patients and diastolic blood pressure was increased. These results suggest that cardiac abnormalities in chronic alcoholics may be reversed after cessation of drinking if no chronic liver disease is present. Recent alcohol consumption increases sympathetic nervous activity, impairs cardiac contractility, and increases afterload during physical stress.

Adult↗
PubMed1987

Effects of autonomic blockade on cardiac function at rest and during upright exercise in humans.

The cardiac function was studied by radionuclide cardiography in eight healthy subjects at rest and during submaximal upright exercise before and after autonomic blockade with metoprolol and atropine. At rest the median stroke volume was reduced by 21% during autonomic blockade (P less than 0.01), but cardiac output was maintained by a concomitant increase in heart rate. The systolic blood pressure was reduced from 120 to 105 mmHg (P less than 0.01), and left ventricular ejection fraction was reduced from 61 to 56% (P less than 0.05). After autonomic blockade the heart rate reached during exercise was the same. Stroke volume and cardiac output were maintained through cardiac dilation. The increase in left ventricular end-diastolic volume was 31 vs. 10% during control conditions (P less than 0.01). The systolic blood pressure was reduced from 174 to 135 mmHg (P less than 0.01). Left ventricular ejection fraction was reduced from 75 to 67% (P less than 0.05), but the increase from rest to exercise was preserved. Total peripheral resistance was reduced by 17% (P less than 0.05). These findings suggest that the heart possesses intrinsic mechanisms to maintain cardiac output during submaximal upright exercise. End-diastolic dilation results in a preserved stroke volume despite a reduced contractility.

Adult↗
PubMed1987

Autonomic nervous control of postprandial hemodynamic changes at rest and upright exercise.

Postprandial hemodynamic changes were studied in healthy subjects at rest and during exercise in the upright position with and without autonomic blockade of the heart. At rest cardiac output increased 61% mostly because of a stroke volume increase accomplished by left ventricular end-diastolic dilation. These changes seemed to be dependent on the autonomic nervous system, whereas the postprandial heart rate increase did not. During exercise cardiac output was 23% higher after food intake due to a rise in both stroke volume and heart rate. These changes were apparently under influence of the autonomic nervous system, whereas left ventricular dilation was not. The present findings indicate that most of the postprandial changes in the central circulation are under control of the autonomic nervous system.

Adult↗