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Biomedical subjects

J M Detry

Publications and source records attributed to J M Detry.

108 records · Page 6Linked to original sources
PubMed1970

Hemodynamic determinants of exercise ST-segment depression in coronary patients.

Eight patients with coronary heart disease were studied during two periods of exercise separated by 30 min of rest; workload was increased in a stepwise fashion every minute of exercise up to a level that produced limiting symptoms of angina, fatigue, or dyspnea. The magnitude of ST-segment depression and the central aortic pressure were measured during exercise and recovery periods, and myocardial oxygen requirements were estimated by the pressure-time index (systolic aortic pressure x heart rate x ejection time). Seven of the eight patients exhibited a close relationship (r ranged from 0.74 to 0.98) between magnitude of exercise ST-segment depression and indices expressing myocardial oxygen requirements; heart rate, blood pressure, and ejection time were also related to magnitude of exercise ST-segment depression. These relationships were reproducible during two consecutive exercises. Like onset of angina, magnitude of exercise ST-segment depression is usually related to hemodynamic factors influencing myocardial oxygen needs. Consequently, comparisons of exercise-induced ST depression before and after therapy (drugs, physical training, and surgery) are valid only if ECG findings are compared at the same level of myocardial oxygen requirements. In contrast, absence of such a relationship during recovery suggests an important difference in mechanisms of the post-exercise electrocardiogram.

Coronary Disease↗
PubMedDate not supplied

Patient compliance and therapeutic coverage: amlodipine versus nifedipine (slow-release) in the treatment of angina pectoris. Belgian Collaborative Group.

Patient compliance with therapy is often poor and overestimated by the treating physician; it is particularly important in cardiovascular diseases such as hypertension and angina pectoris. Compliance was studied in an open parallel study in out-patients with stable angina pectoris, given either amlodipine (5 mg, once daily) or slow-release nifedipine (20 mg, twice daily) for 12 weeks. Compliance was assessed using pill counting and using an electronic device, the medication event monitoring system, to record the time and date of each opening and closure of the pill container. There was no difference between the two groups in pill count or in 'taking compliance' (the percentage of prescribed doses taken as indicated by the monitoring system). Compliance was significantly better (P < 0.001) with amlodipine, however, for 'correct dosing' (the percentage of days on which the correct dose was taken) and for 'timing compliance' (the percentage of doses taken at the prescribed time interval after the last dose). 'Therapeutic coverage' (the estimated proportion of treatment time for which the drug was active) was also significantly better for amlodipine (P < 0.001). There was no difference in reported side-effects between the two therapies.

Aged↗
PubMedDate not supplied

Left ventricular systolic function and diastolic filling at rest and during upright exercise after orthotopic heart transplantation: comparison with young and aged normal subjects.

To evaluate the hemodynamic response to upright exercise of heart transplant recipients, we had 10 patients aged 46 +/- 14 years undergo rest and exercise radionuclide ventriculography 6 to 26 (mean, 14) month after orthotopic heart transplantation. Results were compared with those obtained in 18 young subjects, aged 22 +/- 3 years, and 17 older subjects, aged 56 +/- 5 years. Radionuclide ventriculography was performed at rest and at three levels of exercise, representing 50%, 70%, and 90% of the maximal physical workload. At rest, heart rate was higher in transplant patients than in normal subjects, but during exercise, heart rate increased only 33% compared with a 142% increase in the young subjects and a 111% increase in the older group. During exercise, left ventricular ejection fraction increased in the three groups, but, as compared with the transplant group, the increase of ejection fraction was higher in the young group. End-diastolic volume increased both in transplant patients (+16%) and in older subjects (+13%), whereas it decreased (-20%) in the young subjects during exercise. End-systolic volume decreased in the young group and in the transplant group with exercise, and it did not change in the older group. Cardiac index increased throughout the three levels of exercise in the three groups of subjects, but cardiac index was higher during exercise in young and older normal subjects. With exercise, all three groups showed increases in peak filling rates, but young subjects had a significantly higher value compared with the transplant group. Filling fraction in the first third of diastole did not change with exercise in the transplant and the older group but increased in the young group. We conclude that in transplant patients, increase in cardiac index during upright exercise is mediated by an increase in end-diastolic index during submaximal exercise and by increased heart rate and augmented contractility at peak exercise. Early diastolic filling is altered in these patients, and this alteration is independent from the changes in heart rate and cardiac volumes. When compared with normal persons, this pattern of hemodynamic response to exercise is similar to older subjects but differs from young subjects in whom the increase in heart rate and reduction in end-systolic volume are the chief mechanisms of enhancing cardiac index during exercise.

Adult↗