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Biomedical subjects

J M Detry

Publications and source records attributed to J M Detry.

At least 91 records · Page 5Linked to original sources
PubMed1978

Haemodynamics during maximal exercise after coronary bypass surgery.

Fifty patients underwent an objective measurement of physical working capacity by means of a multistage test of maximally tolerated exertion before and after coronary bypass surgery; 29 patients also had haemodynamic measurements during maximal exercise before and after coronary bypass surgery. The patients were divided into 3 groups according to the degree of revascularisation: adequate (n = 20), partial (n = 17), or none (n = 13). Adequate revascularisation induces a large increase in physical working capacity because of an increased maximal heart rate and maximal cardiac output; stroke volume during maximal exercise and ejection fraction at rest were not modified, suggesting no major changes in left ventricular function. After unsuccessful coronary bypass surgery, the physical working capacity was unchanged despite an increased maximal heart rate; maximal cardiac output was unchanged and stroke volume during maximal exercise was significantly lower. These undesirable results are often associated with perioperative myocardial infarction and are attended by a decreased ejection fraction at rest; these data suggest an impaired left ventricular function after unsuccessful coronary bypass surgery. The results of partial revascularisation are intermediate but appear to be determined by the incidence of partial graft failure which is also often associated with perioperative myocardial infarction. From individual changes in data collected during maximal exercise testing, it is often impossible to predict the degree of revascularisation.

Adult↗
PubMed1978

Influence of resting ECG abnormalities on the ECG response to maximal exercise in women suspected of coronary heart disease.

Coronary arteriographic data have been compared with the ECG response to a maximal exercise test in 53 women with typical or atypical complaints of angina pectoris (AP). All patients with factors known as influencing the repolarization at rest were eliminated and the cases were subdivided according to the presence of a normal (n=26) or abnormal (n=27) resting ECG. The sensitivity (88%) and specificity (81%) of the exertional ECG was not affected by the clinical history nor by the resting ECG data. False positive responses were frequent (32%), particularly among women with atypical AP (50%), but their prevalence was not influenced by the resting ECG data. We conclude that, even in the absence of drug therapy, non-specific resting ECG abnormalities do not influence the ECG response to exercise in women and that they cannot be considered as a factor contributing to the false positive responses: the latter appear to be related to the low prevalence of coronary artery disease in women.

Adult↗
PubMed1977

[Evaluation of the effects of cooling clothes on the adaptation to prolonged exertion in high temperatures by miners].

In order to improve the working conditions of coalminers exposed to high ambient temperature, the authors have studied the effects of wearing an under-vest and a cowl covering the head and shoulders made in sponge-cloth and soaked with cold water (cooling clothes). Eight coalminers volunteered for this study which included three sessions of prolonged intermittent exercise performed in a climatic room with the following ambient temperatures:--experiment A (comfortable environment): td = 28 degrees C; twb = 20 degrees C; bare head and bare torso;--experiment B (hot environment) :td = 38 degrees C; twb = 30 degrees C; bare head and bare torso;--experiment C (hot environment and cooling clothes) : td = 38 degrees C; twb = 30 degrees C; wet undervest and cowl soaked with cold water (16 degrees C) every 15 minutes. Each experiment included 5 periods of exercise each lasting 15 minutes separated by periods of rest lasting 15 minutes; the exercises were performed on a bicycle ergometer or on a treadmill and their intensity corresponded to 50% of the maximal oxygen intake. In the comfortable environment (experiment A), all subjects completed the experiment without undue fatigue; the final heart rate was 81/min and the final rectal temperature was 37.6 degrees C; the weight loss never exceeded 1 Kg. In the hot environment (experiment B), all subjects were exhausted at the end of the study which had to be shortened in 2 cases. The final heart rate was 125/min and the final rectal temperature 38.8 degrees C; the weight loss was above 2 Kg. The use of the "cooling clothes" in the hot environment (experiment C) resulted in significantly (p less than 0.001) lower heart rate (104/min), rectal temperature (38.3 degrees C) and weight loss (1.5 Kg); all subjects completed the experiment, none was exhausted and the "cooling clothes" were appreciated by all subjects. We conclude that the "cooling clothes" tested in the present study significantly reduce the physiological and subjective strain due to intermittent work in a hot environment; this cooling system is simple, of low cost and our results indicate that it is will be very useful in climatic conditions similar to those adopted in the present experimental protocol. Its usefulness in less severe climates has to be established but it might be limited by the subjective reactions of the subjects to the transient but sudden sensation of cold given by the "cooling clothes".

Adaptation, Physiological↗
PubMed1976

Hemodynamic effects of lidoflazine during graded levels of bicycle exercise in normal subjects.

The hemodynamic effects of lidoflazine were studied in 12 young healthy subjects who received the drug orally (240 mg daily) for 8 weeks. During exercise after lidoflazine, heart rate (-2.6%), mean arterial pressure (-3.1%), arterio-venous oxygen (A-V02) difference (-3.4%), pressure rate product (-6.2%), and systemic vascular resistance (-8.6%) were significantly lower, while cardiac output (+5.4%) and stroke volume (+8.3%) were significantly greater. The maximal heart rate was lower after lidoflazine (-6 beats/min) but the maximal oxygen intake (VO2max) was not affected by the drug. The major hemodynamic effects of lidoflazine appear to be, on the one hand, an unexplained decrease in heart rate, and on the other, a decrease in systemic vascular resistance; the latter, which was expected from a vasodilator, could account for the greater stroke volume and contributes to the decrease of the pressure rate product. Lidoflazine has another unexplained effect, i.e. a decrease of the A-VO2 difference, suggesting a decreased peripheral extraction of oxygen at rest as well as during submaximal and maximal exercise.

Adult↗
PubMed1975

Maximal exercise testing in patients with spontaneous angina pectoris associated with transiet ST segment elevation. Risks and electrocardiographic findings.

Six patients with spontaneous angina associated with transient ST segment elevation had a multistate maximal exercise (bicycle) test. In 5 patients, typical electrocardiographic changes were recorded during exercise, namely ST segment elevation often accompanied by an increase in the voltage of the R wave and a widening of the QRS complex. Four of these patients developed severe rhythm disturbances: ventricular tachycardia (2 cases) and ventricular flutter (1 case) were the reason for early interruption of the test in 3 patients, while 1 patient had a short run of ventricular tachycardia after exercise. These rhythm disturbances which spontaneously regressed in all cases were consistently preceded by obvious ST elevation and in 2 patients were attended by slight chest discomfort. Maximal exercise testing of patients suspected of variant angina provides important diagnostic information in many patients, but the risks of potentially lethal arrhythmias should be considered and resuscitation facilities should always be immediately available.

Adult↗
PubMed1975

Early hemodynamic adaptations to physical training in patients with healed myocardial infarction.

Seven patients with coronary heart disease (CHD) but no angina pectoris had hemodynamic studies at rest and during submaximal and maximal exercise levels 2 mth after an acute uncomplicated myocardial infarction. The hemodynamic study was repeated after 3 mth of regular physical training. Maximal oxygen intake (VO2max) increased by 16.1% after physical training while maximal heart rate unsignificantly decreased (minus 3.3%). Higher VO2max after training resulted from an increase in maximal cardiac output (+7%) and stroke volume (+9.2%) and from a widening of the maximal arterio-venous oxygen (A-VO2) difference (+7.3%). The fall in stroke volume observed from submaximal to maximal exercise level was not affected by training. During submaximal exercise, the lower heart rate after training was attended by both a greater stroke volume and a wider A-VO2 difference; the cardiac output slightly decreased. We conclude that the increase in VO2max observed with early physical training in CHD results on one hand from an increased stroke volume whose specificity is not established, and on the other hand from a wider maximal A-VO2 difference; the latter is entirely due to a greater extraction of oxygen from the blood by the working muscles during maximal exercise.

Adult↗