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J R Rebelo

Publications and source records attributed to J R Rebelo.

6 recordsLinked to original sources
PubMed1990

[Inotropic reserve of the left ventricle in patients with chronic ischemic cardiopathy, studied using adrenaline stimulation. Prognostic significance].

AIMS: To study by equilibrium radionuclide angiography (ERNA) the cardiac inotropic reserve after a myocardial infarction, and to evaluate its prognostic value. DESIGN: Patients in a chronic status of a myocardial infarction were studied by ERNA at a basal state and after stimulation with epinephrine, in the same session. Left ventricle (LV) functional abnormalities, global and regional, were evaluated. A 3-to-5 years follow-up was done. PATIENTS AND METHODS: Twenty five patients with a post myocardial infarction were included: 19 with an anterior infarction, 2 with an inferior and 4 with a combined one. All patients had LV dysfunction evaluated by Echocardiogram at hospital discharge. Global and regional LV function were studied by ERNA before and after inotropic stimulation, using increasing doses of epinephrine from 4.8 to 12 micrograms/minute. Heart rate and blood pressure were monitored. ERNA acquisition were done on left oblique best-septal and lateral views, over 400 cardiac cycles, using a Gama-camera GE 400AC. Three groups of patients were considered, according with the change of LV global ejection fraction: increments greater than 2%--group A (positive response); changes between +2% and -2% - group B; decreases greater than 2%--group C (negative response). During a 3 to 5 years follow-up, the incidence of major cardiac events was analysed: cardiovascular mortality, angina, left ventricle failure, myocardial reinfarction and coronary artery by-pass graft surgery. RESULTS: LV global function-Inotropic stimulation was done with an average perfusion time of 30.8 minutes, with total doses of epinephrine between 176 and 660 ng. No significant changes of heart rate (5%) or blood pressure (5.3%) occurred. Basal LV global ejection fraction (EF) was 29.2%. Only 2 patients had a normal LV ejection fraction; 14 patients had a severe LV dysfunction (EF less than 30%) and 9 had a moderate reduction of ejection fraction (EF between 30% and 45%). From the 14 patients with EF less than 30%, twelve had an involvement of the LV anterior wall. After stimulation EF value ineditreased in 9 and decreased in one patient. From the 11 patients with EF greater than 30%, 6 experienced a increase of EF and 3 decreased of EF after stimulation. REGIONAL WALL MOTION: Group A--15 patients--75 segments. In this group 39 segments were related to necrotic ECG localization, and 79% of them contributed to EF increase after stimulation. Forty-one segments were not involved by necrosis, and 78% had a positive contribution to EF increase. Six patients had all LV segments contributing to the EF increase after stimulation. The other 9 patients, had 13 segments not responding to stimulation (EF increments greater than 2%): 5 of them were segments related to ECG site of infarction. Group B--6 patients--30 segments. Five patients had 9 segments with a positive contribution to EF after inotropic stimulation.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1989

[Evaluation of left ventricular function after myocardial infarct using equilibrium radionuclide angiography. 1-year follow-up].

OBJECTIVE: To study the evolution of left ventricular (LV) function in the 1st year after acute myocardial infarction (MI) and to define its prognostic significance. DESIGN: Patients recovering from acute MI submitted to evaluation of LV function by equilibrium radionuclide angiography (RNA) at the time of discharge, three months later and at 12 months of follow-up. PATIENTS AND METHODS: 93 patients suffering an acute transmural MI were submitted to equilibrium RNA. Studies were taken at time of discharge, 3 and 12 months of follow-up. 19 patients had just the 1st study; in 14 the one year follow-up study was not performed. The other 60 include the group submitted to 1 year follow-up. We used the technic of labelled erytrocites in vivo, with acquisition of the blood pool gated with EKG in left lateral. PAGE protocol from GE has been used for processing of images. RESULTS: Mean global ejection fraction (EF) was 20.6 +/- 8.5% for anterior MI with LV failure and 40.2 +/- 14.5% for those without failure; in inferior MI it was 49.9 +/- 12.3% and for combined MI 30.3 +/- 9.5%. The differences between these values are statistically significant. For the 56 patients in which the 1st and 2nd examination were taken we found no significant differences between the mean values for global EF in the 4 groups previously considered. Conversely, we couldn't find a significant difference between the mean EF in the 4 groups, when we compared the values of early (1st and 2nd examinations) test with those of 12 months follow-up. 10 patients (10.8%) died in the 1 year follow-up. All had global EF lower than normal: 33% of deaths in the group with EF less than 20%; 14% in the subset with EF between 20 and 30%; 8% in the sub-group with EF between 30 and 45%. As far as regional motion is concerned we noticed that changes include both the necrotic and the spared areas. We didn't found significant differences between the contribution of necrotic and viable myocardium to the positive or negative variation of global EF, in the 4 groups of infarction considered. Apical segment seems to have an important contribution for global EF changes, both in anterior and inferior MI. CONCLUSION: In this group of patients with acute MI, followed for 12 months, we noticed a higher degree of LV dysfunction in the group of anterior MI. The values of LVEF measured early after the acute attach, usually at hospital discharge are stable along the follow-up, unless major cardiac episodes develop. All the deaths along the one year follow-up had LV dysfunction with EF below 45%. Prognostic "quod vitam" worsened while EF decreased, with a death rate of 33% in the sub-group with global EF less than 20%, and 28% considering those with EF below 30%. In relation with regional motion we found that changes may be elicited both in the necrotic and spared segments. We emphasize the contribution of the apical area to the changes in global EF.

Adult↗
PubMed1989

[Comparison of Holter electrocardiography and thallium 201 scintigraphy in the detection of myocardial ischemia].

OBJECTIVE OF THE STUDY: To compare ischemic changes (I) detected by Holter ECG (H ECG) to the myocardial perfusion defects found in 201 TI myocardial perfusion scintigraphy. DESIGN: 201 TI exercise test was made during the performance of a 24 hours H ECG. The validation of ST segment changes detected by H ECG during the exercise test was made on basis of reversible myocardial perfusion defects (RPD) detected on 201 TL and a relation between ST segment changes detected during the remaining 24 hours recording period and 201 TI (TI) RPD was established. SETTING: The patients (pt) included in the study have come from Cardiology and Heart Surgery Clinics of a Central teaching hospital. MATERIAL AND METHODS: 20 pt with a high coronary artery disease prevalence have been submitted to a two lead (V5 and aVF) 24 hour H ECG during which they have performed a symptom limited bicycle exercise test followed by an injection of 201 TI with acquisition 5 minutes later. Ischemic episodes detected on H ECG were quantified and their relation with heart rate and symptoms was established. As far as 201 TI studies are concerned the fixed and reversible perfusion defects as well as their location were evaluated. RESULTS: 1. H ECG: 6 pt (30%) presented ST changes on H ECG during the exercise test and a total of 9 pt (45%) had ST changes during exercise and during the remaining period of H ECG. 2. TI: 19 pt presented perfusion defects images (fixed in 7, reversible in 14, both kinds of defects in 7). 3. H ECG validation: H ECG during exercise presented I in 6 out of 14 pt with RPD on TI (sensitivity = 43%). Six of these 8 pt, with negative H and positive TI, had a chronic myocardial infarction. All the 6 pt with negative TI had negative H ECG (specificity = 100%). 4. H ECG TI comparison: 7 (50%) of the 14 pt with RPD had ST changes on 24 hrs H ECG. Seven of 11 pt with negative H ECG had RPD in TI. Two pt with negative TI had positive H ECG. These 2 pt had during H ECG a higher heart rate (HR) than the HR recorded during the exercise test. CONCLUSIONS: 1. In pt with known CAD, TI has a high sensitivity and specificity to show perfusion defects. 2. Considering TI as gold standard, H ECG showed to be a useful method to detect I in the studied population (sens. = 43%; spec. = 100%). 3. H ECG revealed to be an important diagnostic tool in detecting additional I episodes beyond the ones recorded during TI exercise test.

Adult↗
PubMed1989

[Congestive heart insufficiency. Evaluation using isotopic methods].

Radioisotopic cardiac studies became, on the last decade, one of the more useful non-invasive methods for the diagnostic evaluation and follow-up of patients with heart disease. Such a contribution of nuclear cardiology is specially noticeable on ischemic heart disease: radionuclide angiography (RNA) allows quantification of left and right ventricular dysfunction, and therefore stands as an ideal technique for the prognostic approach of congestive heart failure. As to diagnosis, RNA is useful in the analysis of regional wall motion abnormalities of ischemic heart disease and detection of ventricular aneurysms. Clinical examples are given of these specific situations. In dilated cardiomyopathies RNA gives not only a measure of ventricular dysfunction, but also a diagnostic information, often definitive, of the diffuse involvement of all left ventricle, and commonly of the right ventricle. Ischemic heart disease, on the other hand, displays different degrees of segmental wall motion impairment together with areas of normal contractility. These aspects are documented with cases of our Registry. Also discussed is the inotropic stimulation technique for the evaluation of the functional reserve of left ventricle in patients with severe rest L.V. dysfunction. Focus is given to the clinical value of isotopic studies for the quantification of valvular regurgitations and pre-operative serial studies in order to define an optimum surgical timing. An attempt is done to grade the practical importance of the different exams of Nuclear Cardiology on the diagnostic and prognostic evaluation on heart disease patients, with a cost benefit relation perspective and comparing with other methods, classic of recent ones, available for the management of patients with heart failure.

Cardiomyopathy, Dilated↗