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Aims The last guidelines recommend a standardized 17-segment model for tomographic imaging of the left ventricle. The aim of this study is to analyse the correspondence of the 17 left ventricular segments with each coronary artery by myocardial perfusion SPECT studies. Methods and results Fifty patients selected for percutaneous revascularization of one coronary artery [24 left anterior descending (LAD), 15 right coronary artery (RCA), and 11 left circumflex (LCX)] were included. The 99m Tc-labelled compound was injected immediately after the inflation of the balloon during percutaneous coronary angioplasty. At least 90 s of complete occlusion time was required. Maximal contour of regions of hypoperfusion corresponding to each coronary artery occlusion were delineated over the polar map of 17 segments. Nine segments corresponded to only one coronary artery: eight to LAD (basal anterior, basal anteroseptal, mid-anterior, mid-anteroseptal, apical anterior, apical septal, apical lateral, and apex) and one to LCX (basal anterolateral). Basal inferoseptal, midinferoseptal, and apical inferior segments could correspond to LAD or RCA. Basal inferior, basal inferolateral, mid-inferior, and mid-inferolateral segments could correspond to RCA or LCX, whereas the mid-anterolateral segment could correspond to LAD or LCX. Conclusion The most specific segments (anterior, anteroseptal, and all apical segments except the infero-apical) correspond to LAD but no segment can be exclusively attributed to the RCA. Inferoseptal segments can be attributed to LAD or RCA, inferior and inferolateral segments to RCA or LCX, and mid-anterolateral segment to LAD or LCX.

Background: The diagnostic value of myocardial perfusion scintigraphy in patients with left bundle branch block (LBBB) and previous acute myocardial infarction has not been evaluated. Objective: To determine the utility of single photon emission computed tomography (SPECT) in patients with LBBB and previous acute myocardial infarction. Methods: Seventy two consecutive patients with permanent LBBB and previous acute myocardial infarction were studied with stress-rest SPECT using 99mTc compounds. The same stress procedures were followed in all patients: (1) exercise alone when it was sufficient; (2) exercise plus simultaneous administration of dipyridamole if exercise was insufficient. Results: In 26 of 28 patients (93%) who had a Q wave acute myocardial infarct before the development of LBBB, there was concordance between abnormal Q waves and rest SPECT in the localisation of myocardial necrosis (κ = 0.836; p = 0.0001). In 48 patients who had coronary angiography, the positive predictive value of exercise (+dipyridamole) myocardial SPECT for the diagnosis of left anterior descending coronary artery stenosis was 93%, for left circumflex coronary artery stenosis, 96%, and for right coronary artery stenosis, 89%. Specificity values were 83%, 91%, and 69%, respectively. However, sensitivity (69%, 64%, and 89%) and negative predictive values (48%, 46%, and 82%) were suboptimal. Conclusions: Rest myocardial perfusion SPECT with technetium compounds is useful for localising healed myocardial infarction in patients with LBBB, and exercise (+dipyridamole) SPECT has a high positive predictive value and specificity for the diagnosis of coronary stenosis in these patients.

Background. We sought to determine the degree of interhospital agreement in the interpretation of exercise myocardial technetium-99m tetrofosmin single photon emission computed tomography (SPECT). Methods and Results. Five experienced hospital laboratories were asked to submit 2 sets of myocardial Tc-99m tetrofosmin SPECT images obtained in 150 patients undergoing coronary angiography: group A used a uniform color scale for all hospitals, and group B used the individual color scale in place at each hospital (uniform color scale, nonuniform color scale, and black-and-white scale). Thus a total of 300 images were interpreted by each center without knowledge of any other patient data. Angiographically significant coronary artery disease (≤50% diameter stenosis) was present in 90 patients (60%). By a majority decision (3 or more centers), the sensitivity was found to be similar for groups A and B (82% and 84%, respectively), but the specificity was significantly higher for group A (87% vs 73%; P = .021). Four or all 5 of the centers agreed on abnormal or normal results of SPECT images in 87% of patients in group A (κ 0.626) and in 78% of patients in group B (κ 0.528). The κ value of 0.617 was obtained for the uniform color scale, 0.467 for the uniform black-and-white scale, and 0.444 for the nonuniform color scale. Agreement on the left anterior descending artery territory (81% for group A and 78% for group B) was similar to that of the right coronary artery territory (79% for A and 75% for B) and to that of the left circumflex artery territory (91% for A and 85% for B). Agreement was similar in patients with 1-, 2-, and 3-vessel coronary artery disease (91%, 88%, and 86% for group A and 81%, 82%, and 82% for group B, respectively). Conclusions. In the interpretation of myocardial Tc-99m tetrofosmin SPECT images, good interinstitutional observer agreement was found, mainly when the uniform display method was adopted.

To demonstrate that the administration of dipyridamole at the end of an insufficient maximal subjective exercise test can improve the diagnostic accuracy of single-photon emission computed tomography in patients with previous myocardial infarction, 209 consecutive patients were studied with technetium-99m methoxyisobutyl isonitrile single-photon emission computed tomography and coronary angiography. Patients were divided in 3 groups: group 1, 107 patients with sufficient exercise testing; group 2, 55 patients with insufficient exercise testing; group 3, 47 patients with insufficient exercise testing in whom intravenous dipyridamole (0.56 mg/kg over 4 minutes) was administered at the end of exercise. In groups 1 and 3 the sensitivity values for the diagnosis of multivessel disease were significantly higher (80% and 76%, respectively) than those in group 2 (59% [p = 0.009 and p = 0.02, respectively]). Specificity and predictive values were not different among the 3 groups. Thus, in patients with previous infarction in whom adequate levels of exercise could not be achieved, dipyridamole administration at the end of exercise significantly increased the sensitivity for diagnosing multivessel disease.

The aim of this study was to assess the prognosis of medically treated patients with “clandestine” myocardial ischemia (perfusion defect without angina and no ST depression >1 mm during exercise test) compared to those with silent myocardial ischemia (ST-segment depression >1 mm, without angina) and those with angina pectoris. One hundred twelve patients without previous myocardial infarction were included. All patients underwent a symptom-limited exercise test on a bicycle ergometer, myocardial perfusion technetium-99m-methoxy-isobutyl-isonitrile single-photon emission computed tomography (SPECT), and coronary angiography. They were classified into 3 groups (angina group, 34 patients; silent group, 20 patients; and the clandestine group, 58 patients). The mean follow-up was 3.6 years (range 6 months to 5.5 years). Patients with clandestine ischemia had a lower scintigraphic and angiographic score than patients with silent ischemia (25 ± 8 vs 31 ± 9 and 24 ± 8 vs 29 ± 7, p = 0.008, respectively), but the prognosis was similar. Only angina and severe reversible SPECT defects were predictive for cardiac events: death + myocardial infarction + revascularization. We conclude that in medically treated patients without previous myocardial infarction, angina and severe reversible SPECT defects are predictive for cardiac events only when the need for revascularization is included as a cardiac event.

Introduccion y objetivos Analizar la eficacia de la tomogammagrafia miocardica de esfuerzo con compuestos tecneciados para el diagnostico de re estenosisen pacientes con angioplastia previa. Pacientes y metodos Se ha analizado retrospectivamente a 71 pacientes con angioplastia previa(16 mujeres, edad media: 60 anos, 35 con enfermedad multivaso y 78 angioplastias en total) y comprobacioncoronariografica. A todos se les habiapracticado, por motivos asistenciales, una tomogammagrafiamiocardica de esfuerzo con 99mTc (53con MIBI y 18 con tetrofosmina) entre 1 mes y 4anos despues de la angioplastia. A 16 pacientes se les administro dipiridamol intravenoso simultaneo con el ejercicio puesto que este fue insuficiente. Resultados La sensibilidad, especificidad, valor predictivo positivo, valor predictivo negativo y valor global de la tomogammagrafia fueron significativamentesuperiores a los de la prueba de esfuerzo (80% frente al 63%; p = 0,05; 83% frente al 37%;p = 0,001; 91% frente al 69%; p = 0,007; 64% frenteal 31%; p = 0,009, y 81% frente al 55%; p = 0,0006 respectivamente). Al comparar los resultados de los pacientes con enfermedad multivaso respecto a los de un solo vaso observamos que fue en estos donde la eficacia diagnostica de la tomogammagrafia fue significativamente superior a la de la ergometria. Conclusiones La tomogammagrafia miocardicade esfuerzo con compuestos tecneciados es una exploracioncon una elevada eficacia para el diagnosticode la reestenosis postangioplastia, sobre todo en los pacientes con enfermedad de un solo vaso.

Introduccion y objetivos El proposito de este estudio es valorar la isquemia miocardica en las regiones dependientes de arterias coronarias ocluidas de pacientes sin infarto previo. Pacientes y metodos Se han estudiado 149 pacientes con enfermedad coronaria demostrada y sin infarto previo mediante tomogammagrafia miocardica de esfuerzo cuantitativa con 99mmetoxi-isobutil- isonitrilo (MIBI) (protocolo largo) y coronariografia. Se cuantifico la extension de la reversibilidad de captacion en 3 regiones (anteroseptal, inferior y lateral) de los mapas polares, valorandose el porcentaje de cada region que tuviera una diferencia entre la captacion en reposo menos la captacion en esfuerzo superior al 10%. Se compararon las regiones dependientes de una arteria ocluida con las dependientes de arterias con estenosis entre el 50 y el 99%, y tambien entre las que no tenian y las que tenian buena circulacion colateral. Resultados Cincuenta y cuatro de 149 pacientes (36%) tenian al menos una arteria coronaria ocluida (20 descendente anterior, 22 derecha y 27 circunfleja). En el analisis visual se observaron defectos reversibles en todos los pacientes con oclusion de la descendente anterior y de la derecha pero solo en la mitad de las oclusiones de la circunfleja. La extension de esta reversibilidad fue significativamente superior en las regiones dependientes de arterias ocluidas, tanto para la descendente anterior como para la derecha y la circunfleja. La extension de esta reversibilidad fue muy variable, aunque inferior cuando existia una buena circulacion colateral. Conclusiones En las oclusiones de la descendente anterior y de la derecha se observan siempre defectos reversibles en la 99mTc-MIBI SPET, mientras que en las de la circunfleja solo se detectan en la mitad de los casos. La extension de la isquemia es superior en las regiones dependientes de una arteria coronaria ocluida, sobre todo en ausencia de una buena circulacion colateral.

Introduccion y objetivos Aunque en diferentes publicaciones se ha comparado la extension de la isquemia entre los pacientes que presentan angina durante la prueba de esfuerzo y los que no la presentan, existen pocos estudios que hayan valorado la importancia pronostica de este hecho. El motivo de este trabajo ha sido analizar el valor pronostico de la presencia de angina durante la practica de una tomogammagrafia de esfuerzo con 99mTc-MIBI en pacientes con cardiopatia isquemica demostrada pero sin infarto previo. Pacientes y metodos Se ha realizado un estudio prospectivo en el que se han incluido de forma consecutiva 82 pacientes con al menos una estenosis coronaria superior al 70% en la coronariografia y con defectos reversibles de perfusion en la tomogammagrafia de esfuerzo con 99mTc-MIBI (protocolo largo). Veintidos enfermos (edad 57 ± 8 anos, 3 mujeres) presentaron angina y 60 (edad 57 ± 9 anos, 7 mujeres) no presentaron angina durante la practica de la prueba de esfuerzo. Se cuantifico la extension de la isquemia en la tomogammagrafia de perfusion y la severidad de la enfermedad coronaria en la coronariografia valorando las complicaciones aparecidas en ambos grupos durante un seguimiento medio de 3,2 anos. Resultados En el examen inicial, los pacientes con angina presentaron una reserva coronaria significativamente menor (duracion del ejercicio 6,3 frente a 8 min; p = 0,03), un menor consumo de oxigeno (5,8 frente a 6,2 MET; p = 0,04), una mayor frecuencia de descenso del segmento ST superior a 1 mm (64 frente a 19%; p = 0,006) y una mayor depresion de este (0,9 frente a 0,4 mm; p = 0,01) que los pacientes sin angina. No se hallaron diferencias significativasen cuanto a la extension de la isquemia en la tomogammagrafia y en cuanto a la severidad de la enfermedad coronaria entre ambos grupos. Durante el seguimiento, la presencia de complicaciones mayores (fallecimiento o infarto) tendio a ser superior en los pacientes con angina (27 frentea 17%; NS) y la necesidad de revascularizacion quirurgica fue significativamente superior (50 frente a 17%; p = 0,002). Conclusiones La presencia de angina durante una gammagrafia de esfuerzo positiva implica un mayor riesgo de complicaciones a medio-largo plazo, principalmente debido a la necesidad de revascularizacion quirurgica.

Objectives. We attempted to demonstrate that simultaneous dipyridamole administration and maximal subjective exercise in patients who are unable to achieve a good exercise level can improve the diagnostic efficacy of technetium-99m methoxy isobutyl isonitrile (99mTc-MIBI) myocardial single-photon emisson computed tomography (SPECT).Background. The results of myocardial perfusion scintigraphy are unsatisfactory if the level of exercise achieved by the patient is insufficient. The use of dipyridamole with maximal subjective stress testing has been shown to improve the quality of the thallium-201 myocardial perfusion images, but there are no studies demonstrating that this combination improves the diagnostic accuracy of myocardial perfusion SPECT.Methods. Two hundred thirty-one consecutive patients, without a previous myocardial infarction, were classified into three groups: group 1, 91 patients with an adequate exercise test; group 2, 68 patients with an inadequate exercise test; group 3, 72 patients with an inadequate exercise test who then received intravenous dipyridamole (0.56 mg/kg body weight over 4 min) simultaneously with exercise.Results. Results for sensitivity (89%) and negative predictive value (83%) in group 3 were significantly better than those in group 2 (71% [p = 0.03] and 56% [p = 0.002], respectively) and not significantly different from those in group 1. The polar maps of 20 patients studied with and without dipyridamole at the same exercise level revealed a significantly greater extent of ischemia in each territory and in a global assessment (19 + 20% vs. 8 + 11%, p < 0.0001) when dypiridamole was administered during physical exercise.Conclusions. Intravenous dipyridamole administration during exercise testing is advisable in all patients who are unable to achieve an adequate exercise level. This approach permits physicians to avoid missing ergometric information while optimizing myocardial SPECT results.(J Am Coll Cardiol 1997;29:531–6)

Introduccion y objetivos Estudiar el rendimientodiagnostico de la tomogammagrafia miocardicacon tecnecio-99m-metoxi-isobutil isonitrilo en ladeteccion de enfermedad individualizada de las arteriascoronarias epicardicas y su valor en la prediccionde enfermedad multivaso. Metodo Se han estudiado 231 pacientes (58 ± 10anos, 26% mujeres) consecutivos sin infarto previoen los que se disponia de una tomogammagrafiamiocardica de esfuerzo y reposo y coronariografia(104 multivaso, 45 monovaso y 82 sin lesiones coronarias).Los resultados de la tomogammagrafiase evaluaron de forma semicuantitativa medianteuna puntuacion proporcional a la extension y severidadde los defectos postesfuerzo (puntuacion maxima:65). Se realizo un analisis bi y multivariableentre los pacientes con enfermedad multivaso ycon enfermedad de un vaso. Resultados La sensibilidad y especificidad de latomogammagrafia para la deteccion de estenosis > 50% en la arteria descendente anterior fuerondel 74% y 85%, para la coronaria derecha del 79% y85% y para la arteria circunfleja del 45% y 96%respectivamente. La tomogammagrafia mostro unasensibilidad del 65%, especificidad del 87%, un valorpredictivo positivo del 81% y un valor predictivonegativo del 76% para la deteccion de enfermedadmultivaso. El analisis bivariable mostro diferencias significativasentre los pacientes de un vaso y multivasoen cuatro parametros: descenso del ST > 1 mm (p =0,01), descenso del ST corregido por la frecuenciacardiaca (p = 0,005), defectos reversibles en masde una region (p = 0,009), y puntuacion de la tomogammagrafia(p = 0,002). En el analisis multivariable la probabilidad de enfermedadmultivaso fue del 90% cuando se asociabadescenso del ST > 1 mm y una puntuacion > 20 en la tomogammagrafia. Cuando estos dos criteriosno se cumplian esta probabilidad fue del 16%. Conclusion Los resultados de la tomogammagrafiamiocardica en la deteccion de enfermedad coronariapor vasos son globalmente buenos exceptopara la circunfleja que presenta una menor sensibilidad.La interpretacion conjunta del ECG de esfuerzoy de la tomogammagrafia permitio una mejordiscriminacion de los pacientes con enfermedadmultivaso.

Background The objective of this study was to determine the prevalence of anterior and septal defects in patients with left bundle branch block (LBBB), and to assess the diagnostic accuracy of myocardial single photon emission computed tomography (SPECT) with technetium compounds in patients with and without LBBB using standard provocative manoeuvres. Methods Five hundred and nine consecutive patients (456 without LBBB and 53 with LBBB) without previous infarction who had a coronary angiography performed within

The accuracy precision of the stress electrocardiogram has been assessed using a meta-analysis of 147 studies that included a total of 24,074 patients [1, 2]. The mean values for the sensitivity and specificity in the 58 studies that included only patients without antecedents of myocardial infarction were 67% and 72%, respectively. As can be seen in Table 1, the results improve when patients who have ST segment depression in the basal ECG, those who are being treated with digoxin and those who have criteria of left ventricular hypertrophy are excluded. These values highlight that the conventional exercise test is an investigation that is more specific than sensitive. Fortunately its sensitivity is lower only with respect to patients with less serious coronary artery disease such as those with single vessel disease.

Over the past few years the evaluation of coronary artery disease has been, essentially, anatomical and based on the coronary angiography. Recently, greater emphasis has been placed on knowledge of the functional repercussions of a particular coronary stenosis and which may be investigated using perfusion gammagraphy; both procedures, however, may be considered complementary in the assessment of the severity of coronary disease [1].

To assess the extent of myocardial necrosis and ischemia in patients with anterior wall healed myocardial infarction depending on whether ST-segment elevation was present on precordial leads during exercise testing, 62 consecutive patients (49 men and 13 women, age [mean +/- SD] 56 +/- 11 years) with anterior wall infarcts were assessed with exercise technetium-99m (Tc-99m) methoxy-isobutyl-isonitrile single-photon emission computed tomography and quantification of the extent of necrosis and ischemia on polar maps: 22 patients hador = 1 mm ST-segment elevation during exercise, and 40 did not. The extent of the necrosis in the anteroseptal (p = 0.001) and apical (p = 0.002) regions, the extent of ischemia in the lateral region (p = 0.003) on polar maps, and the frequency of ventricular aneurysm as shown by cardiac catheterization (p = 0.001) were significantly greater in patients with ST-segment elevation. In a multiple logistic regression model, both extent of necrosis in the anteroseptal region (odds ratio 10.8; 95% confidence interval 2.7 to 44.0) and extent of ischemia in the lateral region (odds ratio 7.25; 95% confidence interval 1.6 to 32.7) were associated with exercise-induced ST-segment elevation. These data suggest that ST-segment elevation in anterior infarctions is associated with wider necrosis in the anteroseptal and apical regions, with a wider extent of ischemia in the lateral region and a higher frequency of ventricular aneurysm. Consequently, it cannot be used as a marker of viability.

Background: The term “culprit lesion” is used to designate the coronary stenosis responsible for the symptoms of the patient with coronary artery disease. Its detection is essential when partial revascularization is contemplated. The term “jeopardized myocardium” is commonly used to mean the amount of myocardium put in danger by all the stenotic lesions; however, it should be restricted to the amount of myocardium that could become infarcted if only the most severe stenoses were occluded. Hypothesis: The aim of this study was to investigate (1) the agreement between coronary myocardial single‐photon emission computed tomography (SPECT) and coronary angiography for the identification of the culprit lesion, and (2) the correlation of the two studies in the quantification of jeopardized myocardium. Methods: In all, 159 patients with coronary artery disease without previous myocardial infarction were included in the study. A score for myocardial SPECT was correlated with the angiographic scores by Califf and Gensini and with the authors' score which includes adjustment for collateral circulation. Results: The agreement between coronary angiography and SPECT for the diagnosis of the culprit lesion was 84% (87/104). The correlations between the scores of angiography and SPECT to assess jeopardized myocardium when all coronary stenoses were taken into account were significant (p