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Biomedical subjects

M Radice

Publications and source records attributed to M Radice.

At least 91 records · Page 5Linked to original sources
PubMed1980

[Electrocardiographic exercise test in assessment of hemodynamic patterns of mitral stenosis (author's transl)].

An ECG exercise test was performed in 36 patients with mitral stenosis, all in sinus rhythm and without digitalis therapy. In 21 subjects (group I = 58.6%) the test was negative, in the other 15 (group II = 41.7%) ischemic abnormalities of the ST segment were recorded during exercise; the mean value for the age is the same in both groups. All patients underwent cardiac catheterization; pulmonary pressure--and in 15 patients also cardiac output with thermodilution technique--were measured at rest and during the same exercise used for the ECG test. No relationship was found between ECG response and pulmonary capillary pressure (PCP), neither at rest nor during exercise, while exercise pressure values were well correlated with those at rest. The group I cardiac index (IC) and systolic index (IS) are significantly higher than in group II; the difference is remarkably more evident for the same indexes recorded during exercise, with splitting values, between the two groups, of 5000 ml/min/m2 for IC and 40 ml/beat/m2 for IS. Heart rate changes induced by exercise were similar in both groups, thus confirming the importance of the behaviour of output indexes. It is therefore possible to identify in mitral disease hemodynamic patterns due to different grouping of pathological features above (PCP) and below (IC) the valvular stenosis. Various hypothesis could be made in order to interpret the relationship between cardiac output and ischemic response to exercise. Anyway our results indicate that exercise ECG test is a non invasive technique useful to identify, among patients affected by mitral stenosis, those with a low IC and, mainly, those in whom this parameter fails to increase adequately with exercise.

Adult↗
PubMed1979

Pharmacodynamic studies in man of the beta-adrenoceptor antagonist DL 071 IT.

DL 071 IT, a new potent non-selective beta-adrenergic blocking drug with intrinsic sympathomimetic activity and weak membrane stabilizing activity, was evaluated alone and in comparison with oxprenolol, in six volunteers, at rest and during an exercise test. Heart rate and systolic pressure were monitored for up to 7 h after oral administration of the drugs. Exercise heart rate and systolic pressure were significantly reduced by both drugs, but only DL 071 IT caused a significant reduction in resting heart rate. As compared to oxprenolol, DL 071 IT has a longer duration of action and is from 5.0 to 13.5 times more potent.

Adrenergic beta-Antagonists↗
PubMed1979

Thallium-201 myocardial imaging in young asymptomatic subjects with "ischaemic" changes in exercise electrocardiogram.

In order to assess the significance of a positive electrocardiographic response to exercise test in 10 asymptomatic subjects with normal resting ECG, a myocardial perfusion scanning with Thallium-201 at rest and during exercise was performed. The following ECG tests were also performed on these subjects: forced hyperventilation, exercise test after nitroglycerin (TNG), exercise test after propranolol. Myocardial perfusion scans did not reveal any defect at rest nor during exercise. Hyperventilation determined abnormalities of ventricular repolarization in all subjects. TNG did not improve the response to exercise test and even decreased the ischemic threshold. After propranolol the electrocardiographic response to exercise became normal in 9 cases, while in 1 subject the ST depressions were impressively reduced. All subjects had a follow-up of 14 to 91 months. During this period none presented symptoms suggesting a coronary disease. This study suggests that combined evaluation of Thallium myocardial perfusion imaging during exercise and exercise ECG test after TNG is most useful in differentiating ischemic from nonischemic exercise ST depressions in asymptomatic population.

Adult↗
PubMed1979

[Alterations of ventricular repolarization at rest, in young asymptomatic subjects. Diagnostic and predictive value of non-invasive methods].

In 34 asymptomatic subjects, aged 16 to 39 years, with clearcut abnormalities of ventricular repolarization on resting electrocardiogram, a forced hyperventilation and maximal exercise test were performed. The stress test was repeated, using the same protocol, after sublingual administration of nitroglycerin (0.3 mg) and of i.v. injection of propranolol (0.1 mg/Kg). In 24 subjects an echocardiogram was recorded: a mitral valve prolapse was present in 6 cases, while in 11 cases minor abnormalities were found. The response to exercise test was positive in 50% of cases. After nitroglycerin the ischemic threshold increased in 7 subjects while it remained unchanged or even lowered in 10 cases. In subjects with a negative stress test nitroglycerin did not produce any important electrocardiographic variations both at rest and during exercise. After propranolol injection the repolarization abnormalities on resting electrocardiogram disappeared or decreased in 23 subjects. The drug increased the exercise tolerance in 4 cases; in other 12 subjects the electrocardiographic response to stress testing became normal. During the follow-up period coronary events occurred in 3 cases; in all of them nitroglycerin had induced an increase of ischemic threshold. Our study suggests that the evaluation of the exercise ischemic threshold after nitroglycerin can be useful in order to identify subjects at high coronary risk.

Adolescent↗
PubMed1979

[The diagnostic value of bloodless methods and follow-up in young asymptomatic subjects with positive exercise test (author's transl)].

Fifty asymptomatic subjects, aged 22 to 40, with normal resting ECG and "ischemic" ST depressions during exercise were followed for 44 +/- 18 months. Coronary events occurred only in two cases. Unexpectedly in 12 subjects the response to maximal exercise became normal. In 25 subjects forced hyperventilation, exercise test after nitroglycerin (TNG), and after propranolol (P) were performed. Hyperventilation determined abnormalities of ventricular recovery in all cases. TNG did not improve the response to exercise, as it does in coronary patients, and even significantly decreased the "ischemic threshold"; after P the exercise test became normal in 20 subjects, while in 5 the electrocardiographic ST depressions were markedly reduced. The responses to pharmacological tests after the follow-up period were similar to the first observation. In 8 subjects, in which exercise ST depressions were particularly impressive, Tallium 201 myocardial scanning at rest and during exercise was performed. Myocardial perfusion imaging did not reveal any defect, thus confirming the non-ischemic nature of the ECG abnormalities. Our results confirm the low predictive accuracy (4%) of a positive stress test in a young asymptomatic population and suggest that, among non-invasive methods, exercise response after TNG is usefull in recognizing the "false positive" tests.

Adult↗
PubMed1979

[Clinical and epidemiological criteria of evaluation of the exercise test (author's transl)].

Exercise test diagnostic and prognostic value depends on the purpose for which is performed and on the population studied. In typical angina patients the test is usefull for choosing between medical and surgical therapy and for evaluating treatment efficacy. In patients with atypical chest pain a diagnostic value is recognized. In asymptomatic subjects results of a number of epidemiological studies suggest that this test is recommended only in selected groups or for research purpose. In the appendix definitions of epidemiological measures used in screening tests evaluation are given with examples.

Adolescent↗