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Biomedical subjects

J M Detry

Publications and source records attributed to J M Detry.

At least 55 records · Page 3Linked to original sources
PubMed1987

Ejection fraction response to upright exercise in hypertension: relation to loading conditions and to contractility.

The respective roles of peripheral and myocardial determinants of exercise ventricular performance were studied in 10 normal volunteers and in 9 mildly hypertensive patients without evidence of coronary disease. Hemodynamic measurements and equilibrium blood pool scintigraphy were simultaneously performed at rest and during maximal upright exercise. In hypertensive patients, mean systolic and diastolic blood pressure were, respectively, 199 +/- 23 and 102 +/- 12 mm Hg at rest, and 271 +/- 28 and 113 +/- 8 mm Hg at peak exercise. Ejection fraction response to exercise was normal (increase by more than 5%) in 4 hypertensive patients (normal hypertensive group: 63 +/- 4 to 77 +/- 6%) and in volunteers (65 +/- 3 to 78 +/- 4%) and abnormal in 5 hypertensive patients (abnormal hypertensive group: 66 +/- 6 to 58 +/- 10% at peak exercise). The abnormal response in the abnormal hypertensive group was not due to an inadequate decrease in systemic vascular resistance during exercise. By contrast, the ratio systolic blood pressure/end-systolic volume, an index of contractility, decreased by 2.3 +/- 4.9 in the abnormal hypertensive group, whereas it increased by 9.8 +/- 9.1 in the normal hypertensive group and by 7.3 +/- 2 in volunteers. Thus, abnormal exercise ejection fraction response in mild hypertension was not related to increased afterload but rather to intrinsic myocardial factors.

Adult↗
PubMed1987

Implementation of the Louvain program for exercise ECG analysis on a microprocessor system.

Several years ago we developed a computer system for the processing of exercise ECGs: the Louvain program for exercise ECG analysis which runs on a minicomputer "Modcomp Classic" and processes XYZ data remotely collected on digital cartridge at the exercise room. This off-line batch procedure is time consuming for the technician (reading of cartridge), but theoretically could be fast. Our experience shows that the results of the exercise test are provided to the referring physician from one day to one week after the procedure because of delays at different levels. The implementation of the programs in a stand-alone unit can produce the results one minute after the end of the test. This solution obviously is more satisfactory for routine clinical testing.

Computers↗
PubMed1986

Alteration of left ventricular diastolic filling in hypertensive patients: effects of nitrendipine and atenolol.

This study was undertaken to determine the chronic effects of a long-acting calcium-channel blocker (nitrendipine) on resting left ventricular filling abnormalities in ten patients with essential hypertension. Radionuclide left ventricular curves of these hypertensive patients were compared with the curves of twelve normal volunteers and of eight asymptomatic older patients. The curves were analyzed for ejection fraction, peak filling rate (normalized for end-diastolic counts and for stroke counts), time to peak filling rate and filling fraction in the first-third of diastole normalized for cycle length. Heart rate and ejection fraction were similar in both control groups and hypertensive patients before and after nitrendipine. Before nitrendipine, diastolic filling parameters were significantly different in the hypertensive patients as compared with the volunteers and with the asymptomatic aged patients: peak filling rate was lower, time to peak filling rate was longer and the first-third filling fraction was smaller. After six weeks of nitrendipine therapy, systolic and diastolic blood pressure decreased significantly. After nitrendipine, the time to peak filling rate decreased and the first-third filling fraction and the peak filling rate (normalized for stroke counts) increased significantly. The acute oral administration of 100 mg atenolol induced a further decrease in systolic blood pressure and a significant decrease in heart rate. The effect of combining nitrendipine and atenolol on diastolic indexes was a preserved effect on time to peak filling rate and on the first-third filling fraction. These results suggest that short-term therapy with nitrendipine improves early diastolic dysfunction in hypertensives: the addition of a beta-blocking agent further improved the early diastolic indexes.

Adult↗
PubMed1986

Acute effects of intravenous indoramin on the hemodynamic adaptation at rest and during exercise in chronic congestive heart failure.

Seven male patients (age 47-70 years) with congestive idiopathic (n = 4) or ischemic (n = 3) cardiomyopathy of functional class 2 (n = 5) or 3 (n = 2) were investigated. In the control study, cardiac output (Fick principle) and intravascular pressures were measured at rest in the supine position and during three consecutive bicycle exercise levels of increasing severity in the sitting position. One hour later, indoramin (0.09 to 0.17, mean: 0.12 mg/kg) was slowly injected over 10 to 20 min in the supine (n = 3) or sitting (n = 4) position and the same protocol was repeated 15 min later. After drug injection, one patient developed major postural hypotension and exercise data were not collected in this patient; data on six patients are thus presented. At rest, indoramin decreased mean heart rate from 91 to 77 beats/min, arterial blood pressure from 123/69 to 102/61 mm Hg, and mean pulmonary arterial pressure from 26 to 22 mm Hg. The effects of indoramin were similar during the three levels of exercise (analysis of variance). At the highest exercise level, heart rate was unchanged (from 135 to 138 beats/min) and cardiac output was slightly increased (from 8.6 to 9.6 L/min); blood pressure (from 166/87 to 155/78 mm Hg); pulmonary arterial pressure (from 49 to 42 mm Hg); mean capillary wedge pressure (from 31 to 22 mm Hg); systemic vascular resistances (from 1,065 to 863 dynes); and total pulmonary resistances (from 523 to 403 dynes) were all significantly lower after indoramin administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1985

Effect of intracoronary thrombolytic therapy on exercise-induced ischemia after acute myocardial infarction.

Intracoronary streptokinase (SK) therapy increases vessel patency rate after acute myocardial infarction (AMI) and thus may lead to a greater exercise-induced myocardial ischemia. This hypothesis was tested in 39 patients enrolled in an angiographically randomized trial of intracoronary SK (19 treated with SK and 20 control subjects); all patients underwent thallium-201 scintigraphy at rest before acute angiography, as well as at rest and during stress 5 to 6 weeks after AMI. The patients were classified into 2 groups based on the presence (n = 13) or absence (n = 26) of complete obstruction of the infarct-related coronary artery at the end of the acute angiography. Semiquantitative score of myocardial thallium uptake was expressed as percent of maximal defect score. Thallium defect score at rest between admission and 5 to 6 weeks' study decreased from 10 +/- 16% units in the control group and from 23 +/- 14% units in the SK group (p = 0.01). This decrease was related to opening of the infarct-related artery (opening 23 +/- 16% vs occlusion 5 +/- 10%). The change in exercise-induced defect score was significantly (p = 0.01) larger in patients in the SK group (11 +/- 6% units) than in those in the control group (5 +/- 7% units). The perfusion defect during exercise was larger (p = 0.006) in patients with incomplete obstruction or reperfusion (10 +/- 6% units) than in patients with complete obstruction (3 +/- 7%). This difference was independent of the number of diseased coronary vessels.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Coronary artery reperfusion in acute myocardial infarction: assessment by pre- and postintervention thallium-201 myocardial perfusion imaging.

In a randomized trial of intracoronary streptokinase (STK) therapy in acute myocardial infarction, 44 patients (21 control subjects and 23 patients treated with STK) underwent sequential thallium-201 planar imaging before angiography and after 4 hours (redistribution), 4 days and 6 weeks. Patients were classified according to the presence or absence of angiographic reperfusion of the infarct-related artery. The semiquantitative score of myocardial thallium uptake was expressed as percent of maximal defect score. Both in control and in STK-treated groups, thallium defect scores decreased over time, but this decrease was smaller in the control group (before angiography, 33 +/- 4%; redistribution, 29 +/- 4%; 4 days, 25 +/- 4%; and 6 weeks, 22 +/- 4%) than in the STK group (44 +/- 4%, 38 +/- 4%, 26 +/- 4% and 21 +/- 3%, respectively). In patients in whom reperfusion was achieved (20 STK-treated, 6 control subjects), a marked decrease in thallium score was observed (before angiography, 40 +/- 4%; redistribution, 32 +/- 4%; 4 days, 20 +/- 5%; and 6 weeks, 14 +/- 22%) compared with patients in whom reperfusion was not achieved (37 +/- 4%, 36 +/- 5%, 33 +/- 5% and 33 +/- 4%, respectively). These results indicate that serial thallium imaging is an accurate method of assessing changes in myocardial perfusion after acute myocardial infarction. Restoration of thallium uptake was observed after reperfusion of the infarct-related artery whether this recanalization was seen spontaneously or after successful thrombolysis.

Aged↗
PubMed1985

Radionuclide absolute left ventricular volumes during upright exercise: validation in normal subjects by simultaneous hemodynamic measurements.

A nongeometric radionuclide technique for the determination of absolute left ventricular volumes was validated during exercise in nine normal subjects. Simultaneous reference stroke volume and cardiac output measurements were obtained by the Fick method. The reference left ventricular volumes were calculated by combining the Fick stroke volume and the isotopic ejection fraction. Data were collected at rest in the supine and upright positions and during 60 degrees upright exercise, at three levels of increasing severity. At rest, from supine to upright position, the reference end-diastolic volume decreased significantly from 182 +/- 24 ml to 154 +/- 21 ml (mean +/- SD, P less than 0.005); during upright exercise of low intensity, end-diastolic volume increased to 176 +/- 24 ml (P less than 0.05); at maximal exercise, end-diastolic volume was not different from the resting value in upright position. The end-systolic volume gradually decreased at rest from 67 +/- 11 ml in the supine position to 54 +/- 8 ml in the upright position (P less than 0.05). Compared with these reference data, the scintigraphic measurements were significantly lower on average by 23% for stroke volume, 21% for cardiac output, 22% for end-diastolic volume, and 23% for end-systolic volume. The overall changes in stroke volume (P less than 0.05) and end-systolic volume (P less than 0.001) occurring at rest and during exercise were correctly detected by the scintigraphic method but the smaller changes in end-diastolic volume (less than 15%) were not (P less than 0.15) because they were within the range of the precision of the technique.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Prognostic value of symptom limited exercise testing in men with a high prevalence of coronary artery disease.

In order to evaluate the independent prognostic information provided by exercise testing in populations with a high prevalence of coronary artery disease, survival rates were calculated with the life table method in 372 men, mean age 48 years, referred for coronary arteriography. The prevalence of angiographic coronary artery disease was 82%. During a mean follow-up of 29 months (1 to 8 years), 32 patients died and 27 patients had a nonfatal event (acute infarction or hospitalization for disabling angina). Both the history (presence or absence of typical angina pectoris or of a previous myocardial infarction) and the exercise test results (abnormal if angina and/or ST segment changes greater or equal to 0.1 mV occurred) had a significant prognostic value for the 5 year survival rate (P less than 0.001). In patients with a positive history, the 5 year cumulative survival rate was 76% if the exercise test was abnormal versus 94% if it was normal (P less than 0.001). The following 8 noninvasive and 2 invasive variables were submitted to a Cox regression analysis: age, typical angina pectoris, previous myocardial infarction, maximal heart rate and workload, maximal ST segment depression and elevation, angina pectoris during exercise testing, number of diseased vessels, and wall motion score on contrast ventriculography. By univariate analysis, the age and the maximal workload reached during exercise were the only noninvasive predictive variables for survival or cardiac events (P less than 0.05). By multivariate analysis, and combining all noninvasive and invasive variables, survival was predicted by the wall motion score, the presence or absence of 3 vessel disease, and age.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

Diagnostic value of computerized exercise testing in men without previous myocardial infarction. A multivariate, compartmental and probabilistic approach.

The value of exercise testing for the diagnosis of coronary artery disease is disputed but very few studies have taken advantage of all recent improvements, namely computer averaging of the ECG signals, multivariate analysis of the data, a compartmental diagnostic approach and probabilistic interpretation of the results. These methods were tested in a group of 387 men who had a computer-assisted multistage maximal exercise test; none had a history of myocardial infarction. In 284 symptomatic patients, the diagnosis was made by arteriography; 103 ostensibly healthy men were also included. The computer-averaged ECG signals (X, Y, Z) recorded at maximal exercise, maximal heart rate, blood pressure and workload, and the onset of angina pectoris during exercise were submitted to a multivariate stepwise discriminant analysis. The pretest likelihood for CAD was calculated from age and history; the post-test likelihood was calculated from Bayes' theorem and the average information content of several diagnostic methods was assessed in categorical and compartmental models. By multivariate analysis, 5 variables collected at maximal exercise were selected, namely the heart-rate, the ST60 segment level, the onset of angina during the test, the workload and the slope of the ST segment in lead X. The average information content of the analysis using 5 variables was 44% in a categorical model versus 55% in a compartmental model (P less than 0.001). For comparison, the information content of the analysis using the ST60 segment level alone was only 16% in the categorical model and 27% in the compartmental model. The clinical value of these diagnostic methods (categorical versus compartmental, univariate versus multivariate) was assessed by a probabilistic classification of the patients. The classification provided by the analysis of the ST60 segment changes was barely better than that one provided by the simple history. The probabilistic use of a multivariate and compartmental analysis of the data led to a significantly better and more accurate classification of the patients (83% of correct classification).

Adult↗
PubMed1985

Alternative diagnostic strategies for coronary artery disease in women: demonstration of the usefulness and efficiency of probability analysis.

Alternative strategies using conditional probability analysis for the diagnosis of coronary artery disease (CAD) were examined in 93 infarct-free women presenting with chest pain. Another group of 42 consecutive female patients was prospectively analyzed. For this latter group, the physician had access to the pretest and posttest probability of CAD before coronary angiography. These 135 women all underwent stress electrocardiographic, thallium scintigraphic, and coronary angiographic examination. The pretest and posttest probabilities of coronary disease were derived from a computerized Bayesian algorithm. Probability estimates were calculated by the four following hypothetical strategies: SO, in which history, including risk factors, was considered; S1, in which history and stress electrocardiographic results were considered; S2, in which history and stress electrocardiographic and stress thallium scintigraphic results were considered; and S3, in which history and stress electrocardiographic results were used, but in which stress scintigraphic results were considered only if the poststress probability of CAD was between 10% and 90%, i.e., if a sufficient level of diagnostic certainty could not be obtained with the electrocardiographic results alone. The strategies were compared with respect to accuracy with the coronary angiogram as the standard. For both groups of women, S2 and S3 were found to be the most accurate in predicting the presence or absence of coronary disease (p less than .05). However, it was found with use of S3 that more than one-third of the thallium scintigrams could have been avoided without loss of accuracy. It was also found that diagnostic catheterization performed to exclude CAD as a diagnosis could have been avoided in half of the patients without loss of accuracy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Validation of radionuclide cardiac output measurements during exercise.

A nongeometric radionuclide technique with correction for attenuation was used for the determination of cardiac output and stroke volume during exercise in nine normal subjects and in ten hypertensive patients. Simultaneous reference stroke volume (range 48-159 ml) and cardiac output (range 3.6-23.8 l/min) measurements were obtained by the Fick method. Data were collected at rest and during 60 degrees upright exercise, at two or three levels of increasing severity. Three statistical measurements were used for the comparison of both methods: correlation, precision, and accuracy. Radionuclide and Fick cardiac output measurements (n = 67, rest and exercise data) correlated well (r = 0.90). For stroke volume, the correlation was less (r = 0.64); however, the precision or random variability of both methods was similar for stroke volume (radionuclide: 8 ml or 9%; Fick: 16 ml or 16%). The accuracy or systematic error was defined as the mean difference between radionuclide and Fick measurements. The radionuclide method underestimated the Fick measurements. The systematic error was 18 +/- 18 ml for stroke volume and 2.4 +/- 2.4 l/m for cardiac output. A similar comparison of both methods was made on the absolute changes of stroke volume (r = 0.61; range -19 + 70 ml) and cardiac output (r = 0.82; range +1.6 + 16.4 l/m) between rest and exercise. The precision of the two methods was similar; the systematic error was 1.9 +/- 2.2 l/m for cardiac output and 6 +/- 17 ml for stroke volume. Thus, in these two groups of patients, although radionuclide and Fick cardiac output measurements at rest and during exercise correlated well, the radionuclide values were systematically and significantly lower.

Adult↗
PubMed1984

Antianginal effects of corwin, a new beta-adrenoceptor partial agonist.

The hemodynamic effects of corwin were evaluated in 9 patients with coronary artery disease and without clinical signs of heart failure at rest, during submaximal exercise and during exercise-induced angina pectoris before and after administration of corwin. Angina pectoris was always prevented after the drug was given and the exercise intensity was increased until recurrence of angina pectoris; hemodynamic data were also recorded at this higher exercise capacity (+16%: p less than 0.001). At rest, corwin increased heart rate (from 80 to 84 beats/min) and pressure-rate product. During submaximal exercise, heart rate decreased from 105 to 96 beats/min, and pressure-rate product and ST-segment depression also decreased after corwin. The prevention of angina pectoris in all patients was accompanied by a lower heart rate (from 132 to 117 beats/min), pressure-rate product and ST-segment depression. At rest and during exercise, the cardiac output was unchanged and the pulmonary capillary wedge pressure was slightly decreased after corwin (from 12.5 to 10 mm Hg; p less than 0.001). At the 16% greater exercise capacity after corwin, angina pectoris recurred at the same values of cardiac output, pulmonary wedge pressure and ST-segment depression; maximal heart rate decreased from 132 to 124 beats/min, and the pressure-rate product was lower. Thus, corwin is an active antianginal drug. Its effects are likely due to a decrease in pressure-rate product and myocardial oxygen requirements during exercise. In contrast to beta-antagonists devoid of partial agonist activity, corwin does not depress left ventricular function either at rest or during exercise.

Adrenergic beta-Agonists↗
PubMed1984

Role of exercise testing and stress thallium scintigraphy in the management of old men with suspected or documented coronary artery disease.

From 217 old men submitted to a symptom-limited maximal exercise test, 145 had also an exercise thallium scintigraphy; 44 of those patients were submitted to an angiography. The decision to perform angiography in these aged patients was based mostly on their history and their complaints. This decision was likely influenced by the results of the exercise test; even in symptomatic patients, angiography was rarely performed when the exercise data were normal (normal ECG, no angina during the test). The thallium scintigraphy was not a major element in the overall clinical decision making: when the scintigraphy was available, it contributed, however, to refine the decision whether or not to perform an angiography.

Aged↗