[Study of post-myocardial infarction ventricular aneurysms with equilibrium radionuclide angiography. Significance of Fourier analysis]. / Estudo dos aneurismas ventriculares pós-enfarte do miocárdio pela angiografia de radionuclidos de equilíbrio. Importância da análise de Fourier.

The concept of left ventricular aneurysm has been a subject of controversy and it's not yet completely settled. This has some implications on the patients selection for surgery and explains the various non-invasive methods so far developed for the clinical assessment of patients with ventricular aneurysms. Seventy-one patients with ischemic heart disease, 65 with recent myocardial infarction, were studied by equilibrium radionuclide angiography (ERNA) in order to define left ventricular wall motion abnormalities. One hundred ERNA were undertaken, through the usual erytrocites in vivo labelling technic, employing a GE 400 T Gama-Camera GP. Image acquisition was through 400 cardiac cycles, on LAO (30 and 60 degrees) and left lateral. PAGE protocol was employed. Fourier transform was used in the present work to obtain phase and amplitude images, which actually became the main criteria to define aneurysmatic areas. Global ejection fraction, regional wall motion and regional ejection fraction were other parameters investigated. Wall motion abnormalities have been identified in all the 65 patients having suffered a myocardial infarction. Extensive areas of akinesia or localized dyskinesia were present in 40 patients (16.5%), while remainder 25 had just localized hypoakinesia. Phase image enabled the selection of LV areas of contraction delay in 19 of the 40 patients with extensive wall motion abnormalities (Group I). In such Group I we could identify an LV area with contrasting colour, defining the aneurysmatic LV portion. In the order 21 patients with extensive akinesia, no significant changes of colour were present on ventricular phase image (Group II) meaning absence of aneurysm. No phase disturbances were seen in the remainder 25 patients with MI (Group III) and the 6 patients with CAD without MI had normal phase images (Group IV). The percentage of akinetic segments was 39.1 and 35.4 in Group I and II, respectively (p = .53) while it was significantly lower in Group III 17.9%; p < .0001). LV ejection fraction was statistically different in the four groups considered (I = 30.0% +/- 3.7; II = 39.9% +/- 2.9; III = 49.0% +/- 2.5; IV = 62.0% +/- 3.2). The degree of phase delay in aneurysmatic zones was quantified by the phase histogram. Average value of phase for the left ventricle was 129.7 +/- 8.4 degrees, and for the aneurysm it was 238.0 +/- 5.0 with an average phase delay of 104.8 +/- 4.1 degrees. The association of phase and amplitude images and the measurements of phase and amplitude values on the histograms allowed the distinction of akinetic aneurysm (phase delay and low amplitude) from the dyskinetic aneurysms (phase delay and high amplitude). Half of the isotopic diagnosis of aneurysms have been confirmed by classic contrast angiography, and a third of then have undergone surgery. The two dyskinetic aneurysms that have been submitted to aneurysmectomy had pos-operative improvement of LV function. On summary, phase and amplitude analysis by the Fourier method, which is independent of LV geometry, showed that LV regions with high phase values are associated with severe regional wall motion abnormalities and low ejections fractions. The definition of the sequence and amplitude of ventricular contraction allows the distinction of akinetic and dyskinetic aneurysms, anticipating the method as a valid contribution for the screening of patients likely to benefit from aneurysmectomy.

Cardiac valve calcification in haemodialysis patients: role of calcium-phosphate metabolism.

BACKGROUND: Cardiac valve calcification (VC) has been detected with increased frequency in haemodialysis (HD) patients, making it necessary to determine the potential pathogenic factors in uraemic patients. METHODS: A total of 92 chronic HD patients (39 female, 53 male) and 92 age and gender-matched nondialysis control subjects were evaluated by echocardiography and a severity score for VC was determined. Calcium phosphate metabolism was evaluated at the beginning of haemodialysis. RESULTS: We found a greater prevalence of VC in dialysis patients than in normal patients (mitral annulus 44.5% vs 10%, P = 0.02; aortic annulus 52% vs 4.3%, P = 0.01). HD patients with mitral calcification were found to be older than patients without calcification, were on long-term renal replacement therapy, had longer duration of predialysis arterial hypertension, had greater values of the highest value of mean calcium phosphate product in 6 successive months (CaxP) and the highest absolute value of calcium-phosphate product (CaxPmax). We also found a positive correlation between calcification score, age, and CaxP. No correlation was found between actual VC and arterial hypertension or parathyroid hormone. Multiple stepwise regression analysis selected age and CaxP as the most predictive parameters for mitral calcification (r = 0.47). Mitral calcification was associated more frequently with rhythm and cardiac conduction defects, valvular insufficiency and with peripheral vascular calcification. Aortic calcification was correlated with age (r = 0.42) and longer duration of predialysis arterial hypertension. CONCLUSION: Our study confirmed an increased prevalence of VC in HD patients and selected age and calcium phosphate product as the most predictive parameters. These findings support careful monitoring of calcium metabolism beginning at the early stages of end-stage renal failure to reduce the risk of heart disease.

[Inotropic reserve of the left ventricle in patients with chronic ischemic cardiopathy, studied using adrenaline stimulation. Prognostic significance]. / Reserva inotrópica do ventrículo esquerdo, em doentes com cardiopatia isquémica crónica, estudada pela estimulação com adrenalina. Significado prognóstico.

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)

[Congestive heart insufficiency. Evaluation using isotopic methods]. / Insuficiência cardíaca congestiva. Avaliação por métodos isotópicos.

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.

[Comparison of Holter electrocardiography and thallium 201 scintigraphy in the detection of myocardial ischemia]. / Comparação entre a electrocardiografia de Holter e a cintigrafia com tálio 201 na detecção de isquemia miocárdica.

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.

[Evaluation of left ventricular function after myocardial infarct using equilibrium radionuclide angiography. 1-year follow-up]. / Avaliação da função ventricular esquerda no pós-enfarte do miocárdio pela angiografia de radionuclidos de equilíbrio. Seguimento de 1 ano.

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.