[Morphologic classification of hypertrophic cardiomyopathy with myocardial single photon emission tomography. Comparison with echocardiographic classification]. / Clasificación morfológica de la miocardiopatía hipertrófica mediante tomogammagrafía miocárdica. Comparación con la clasificación ecocardiográfica.

INTRODUCTION AND OBJECTIVES: The aim of this study was to compare different morphologic types of hypertrophic cardiomyopathy obtained by single photon emission tomography to those obtained by echocardiogram. MATERIALS AND METHODS: In 76 (64%) out of 119 patients with hypertrophic cardiomyopathy the echocardiogram permitted an optimal visualization of all left ventricular segments in the short axis view and consequent classification to one of the six morphological types: type I (septal anterior hypertrophy), type II (septal anterior and septal posterior hypertrophy), type III (septal and antero-lateral hypertrophy), type IV (antero-lateral and/or septal posterior hypertrophy), type V (concentric hypertrophy) and type VI (apical hypertrophy). Without knowledge of echo data, two experienced observers included the short axis of single photon emission tomography images at rest (99mTc-tetrofosmin) to one of those types. RESULTS: Global concordance between echocardiogram and single photon emission tomography was 75%. Type III was the most frequent both in echo (76%) and in single photon emission tomography (74%) and type III produced the majority of discrepancies. SPET identified 4 patients with a predominant septal and inferior hypertrophy, that did not correspond to any of the 6 types of echocardiographic classification and had been previously classified as type III by echo in 3 cases and as type V in 1 case. CONCLUSIONS: There was agreement between echo and single photon emission tomography in the morphological classification of most of the patients (75%) with hypertrophic cardiomyopathy. Nevertheless, some discrepancies were observed for the type III echocardiogram.

[Influence of ergometric parameters on the results of myocardial perfusion tomographic scintigraphy]. / Importancia de los parámetros ergométricos en los resultados de la tomogammagrafía de perfusión miocárdica.

BACKGROUND: The percentage of peak predicted heart rate that is accepted to consider as sufficient a given exercise test is 85%. However, the optimal value of such rate and other exercise parameters for the purposes of myocardial single-photon emission tomography is not well established. PATIENTS AND METHODS: With the aim of establishing the minimal levels of maximal heart rate, product heart rate x systolic blood pressure and ventilatory oxygen uptake to obtain an adequate diagnostic efficacy of myocardial perfusion scintigraphy, 159 patients with coronary artery disease or suspicion of this without previous myocardial infarction were studied with stress test single photon emission tomography with 99mTc-methoxi-isobutil-isonitrile. All the patients were coronary angiography tested. RESULTS: Sensitivity and negative predictive value were significantly higher at levels of heart rate > 80% (93 vs 78%; p = 0.002 and 94 vs 56%; p = 0.0004), product heart rate x systolic blood pressure > 18,000 (88 vs 78%; p = 0.04 and 84 vs 52%; p = 0.004) and > 5 METs (85 vs 77%; p = 0.002 and 74 vs 69%; p = 0.03). CONCLUSIONS: Sensitivity and negative predictive value of stress test single photon emission tomography with 99mTc-methoxi-isobutil-isonitrile are low if levels higher than 80% of heart rate, 18,000 of product of heart rate x systolic blood pressure and 5 METs have not been achieved.

[Diagnosis of coronary disease by means of stress gamma-tomography with 99m-technetium-isonitriles]. / Diagnóstico de la enfermedad coronaria mediante la tomogammagrafía de esfuerzo con isonitrilos-tecnecio-99m.

BACKGROUND: To assess the yield of exercise myocardial stress tomogammagraphy (SPET) with methoxy-isobutyl-isonitrile-technetium-99m (99mTc-MIBI) in the diagnosis of coronary artery disease. METHODS: Seventy-two consecutive patients, without previous myocardial infarction and with coronary angiography, were investigated. All underwent a symptom-limited exercise test with intravenous infection of 15 mCi of 99mTc-MIBI 30-60 seconds before the end of exercise. Detection of tomographic images was performed after one hour. Rest images were detected 24 hours later. Images with exercise perfusion defects which became normal at rest were considered as positive. RESULTS: Sensitivity (84%), specificity (93%), global value (87%), positive predictive value (95%), and negative predictive value (79%) of 99mTc-MIBI were significantly higher than those of conventional exercise electrocardiogram (46%, 69%, 55%, 69% and 46%, respectively). These values were lower when exercise test was insufficient (peak heart rate below 80% in the absence of angina). The sensitivity values were similar for the diagnosis of one (81%), two (76%), and three (93%) vessel disease. The application of Bayes' theorem disclosed that the highest yield of MIBI was achieved with prevalences ranging between 30% and 70%. CONCLUSION: The efficacy of 99mTc-MIBI SPET for the diagnosis of coronary artery disease was satisfactory, particularly when exercise was sufficient and with a prevalence of coronary artery disease ranging between 30% and 70%.

[The diagnosis of ventricular pseudoaneurysms. The complementary role of echocardiography, isotopic ventriculography and contrast ventriculography]. / Diagnóstico de los seudoaneurismas ventriculares. Papel complementario de la ecocardiografía, la ventriculografía isotópica y la ventriculografía de contraste.

The diagnostic yield of echocardiography, radionuclide ventriculography (first pass and multiple gated) and contrast ventriculography was evaluated in 11 patients in whom a diagnosis of left ventricular pseudoaneurysm had been made during the last ten years. The diagnosis was made by two dimensional echocardiography (associated with Doppler in the last 5 patients) in 8 of 11 patients (sensitivity: 73%). The major limitation of the technique, in addition to the impossibility of an adequate recording due to a suboptimal acoustic window, is the poor definition of the neck of the pseudoaneurysm, particularly in the inferior localization. By contrast, echocardiography is the only technique which permits the direct visualization of thrombi within the pseudoaneurysm. Multiple gated radionuclide ventriculography was diagnostic in 7 of 10 patients (sensitivity: 70%). Its major limitations are the poorer spatial resolution to visualize the pseudoaneurysm neck and the thrombi within the cavity. First pass radionuclide ventriculography was diagnostic in 4 of 6 patients (sensitivity: 67%). In one of them it improved on the diagnostic yield of the multiple gated technique. Contrast ventriculography was diagnostic in 5 of 7 patients (sensitivity: 71%). The diagnosis was missed due to technical problems in one patient and to significant thrombosis within the pseudoaneurysm in another. Thus, none of the imaging studies has optimal sensitivity. Therefore, all play a complementary role in the diagnosis of ventricular pseudoaneurysm.

Diagnostic accuracy of radionuclide techniques in patients with equivocal electrocardiographic exercise testing.

The aim of the present study was to evaluate the yield of radionuclide studies for the diagnosis of coronary artery disease (coronary artery narrowing greater than 50%) in a prospective series of 73 patients with thoracic pain and equivocal electrocardiographic stress testing. In the study population, the prevalence of coronary artery disease was 51%. The sensitivity, specificity, diagnostic accuracy and the post-test probability difference curves according to the Bayes' theorem were calculated for 201-thallium exercise testing and radionuclide exercise equilibrium ventriculography. For the latter study the following criteria were considered: (1) increase in left ventricular ejection fraction less than 5%; (2) the criterion proposed by Rozanski; (3) decrease in regional ejection fraction; and (4) abnormalities in phase and amplitude analysis (Fourier). 201-thallium exercise testing was the most sensitive (97%) and accurate (86%) study. Radionuclide ventriculography sensitivity was always lower for any criterion, although its best result was for evaluation of regional ejection fraction (85%). The most specific study was Fourier analysis (97%), although its sensitivity was low (42%). The application of Bayes' theorem to these results shows that the highest post-test probability difference values were achieved with 201-thallium exercise testing for prevalences higher than 40% and with Fourier analysis for lower prevalences.