ABSTRACT
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 (kappa = 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.
Subject(s)
Bundle-Branch Block/diagnostic imaging , Myocardial Infarction/diagnostic imaging , Tomography, Emission-Computed, Single-Photon/methods , Aged , Analysis of Variance , Coronary Stenosis/diagnostic imaging , Dipyridamole , Exercise Test , Female , Humans , Male , Organophosphorus Compounds , Organotechnetium Compounds , Radiopharmaceuticals , Sensitivity and Specificity , Vasodilator AgentsABSTRACT
Objetivos: Valorar el papel del SPET miocárdico de perfusión y de la ventriculografía isotópica en la miocardiopatía hipertrófica (MH).Material y Métodos: A una serie consecutiva de 101 pacientes (54 ñ 15 años de edad, 50 mujeres, 55 obstructivos), diagnosticados por ecocardiograma-Doppler de MH, se les practicó un SPET miocárdico de perfusión con 99mTctetrofosmina y una ventriculografía isotópica. El seguimiento medio desde el momento del diagnóstico fue de 9,9 ñ 6,7 años (entre 1 y 28 años). Resultados: El 36 por ciento de los pacientes presentaron defectos de perfusión (15 defectos fijos y 21 defectos reversibles). En las MH no obstructivas se observó un mayor número de pacientes con defectos fijos (p = 0,01) y en los pacientes con defectos fijos se observó una mayor incidencia de ondas Q patológicas en el ECG (p = 0,01), mayores volúmenes ventriculares (p < 0,05), menor fracción de eyección (p = 0,001) y un tiempo a la velocidad máxima de llenado ventricular superior (p < 0,05). Cuatro pacientes fallecieron, 15 presentaron síncope, en 18 se indicó la implantación de marcapasos y en 6 miectomía. La fracción de eyección fue más alta en los pacientes que presentaron síncope (p = 0,034) mientras que ninguna variable isotópica fue predictora de mortalidad ni de indicación de marcapasos o miectomía. Conclusiones: Ni la tomogammagrafía miocárdica de perfusión ni la ventriculografía isotópica aportan información pronóstica en la MH, aunque en los pacientes con síncope se observan valores de fracción de eyección más elevados. Los pacientes con defectos fijos presentan mayor proporción de ondas Q patológicas en el ECG, mayores volúmenes ventriculares y fracción de eyección más baja en la ventriculografía isotópica, lo cual indica una evolución hacia la forma dilatada de la MH (AU)
Subject(s)
Middle Aged , Adult , Male , Female , Humans , Radionuclide Ventriculography , Tomography, Emission-Computed, Single-Photon , Coronary Circulation , Stroke Volume , Disease Progression , Perfusion , Pacemaker, Artificial , Prognosis , Retrospective Studies , Follow-Up Studies , Cardiomegaly , Heart , Cardiomyopathy, Hypertrophic , Cardiomyopathy, Dilated , Exercise TestABSTRACT
OBJECTIVE: To evaluate the role of myocardial perfusion SPET and radionuclide ventriculography in patients with hypertrophic cardiomyopathy (HC). METHODS: Exercise myocardial perfusion SPET with 99mTc-tetrofosmin and radionuclide ventriculography were performed in a consecutive series of 101 patients (54 15 years, 50 women, 55 with dynamic obstruction) diagnosed of HC by echo. Follow-up from the diagnosis was 9,9 6,7 years (1 to 28 years). RESULTS: Thirty six percent of patients had perfusion defects (non reversible in 15 and reversible in 21). In non obstructive HC higher number of patients with non reversible defects (p = 0.01 was obseved and in patients with no reversible defects higher incidence of pathologic Q waves in ECG (p = 0.01), Higher ventricular volumes (p < 0.05), lower ejection fraction (p = 0,0001) and longer time to peak emptying velocity (p < 0.05). There were 4 cardiac deaths, 15 syncopes, 18 pacemakers and 6 myectomy. Ejection fraction was higher in patients with syncope (p = 0,034) and there was no isotopic variable predictive of mortality, pacemaker or myectomy. CONCLUSIONS: Neither SPET nor radionuclide ventriculography have a prognostic role in patients with HC, but patients with syncope have higher values of ejection fraction. Patients with non reversible defects have higher rate of pathologic Q waves in ECG, higher ventricular volumes and lower ejection fraction. This is indicative of evolution to dilated form of HC.
Subject(s)
Cardiomegaly/diagnostic imaging , Cardiomyopathy, Hypertrophic/diagnostic imaging , Coronary Circulation , Heart/diagnostic imaging , Radionuclide Ventriculography , Tomography, Emission-Computed, Single-Photon , Adult , Cardiomegaly/complications , Cardiomegaly/mortality , Cardiomegaly/therapy , Cardiomyopathy, Dilated/etiology , Cardiomyopathy, Dilated/mortality , Cardiomyopathy, Hypertrophic/complications , Cardiomyopathy, Hypertrophic/mortality , Cardiomyopathy, Hypertrophic/therapy , Disease Progression , Exercise Test , Female , Follow-Up Studies , Heart/physiopathology , Humans , Male , Middle Aged , Pacemaker, Artificial , Perfusion , Prognosis , Retrospective Studies , Stroke VolumeABSTRACT
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 <3 months of the scintigraphic study were retrospectively evaluated. The same stress procedures were followed in all patients. (1) Only exercise when it was sufficient; and (2) exercise + simultaneous administration of dypiridamole if exercise was insufficient. Only reversible defects were considered positive and > or =50% of coronary stenosis was considered significant. RESULTS: Prevalence of reversible anterior and septal defects was low (33% and 12%, respectively) in patients with LBBB. Although lower values of global sensitivity (81%) and specificity (73%) were obtained in these patients, there were no significant differences with respect to the patients without LBBB (89% and 86%, respectively). Specificity values for the diagnosis of stenosis of left anterior descending (78%), left circumflex (96%) and right coronary artery (74%) in patients with LBBB were lower, but without significant statistical differences with respect patients without LBBB (90%, 96% and 82%, respectively). CONCLUSIONS: Myocardial SPECT with technetium compounds, using standard provocation manoeuvres, can be used in patients with LBBB with only a mild decrease in diagnostic accuracy as compared to patients without LBBB.
Subject(s)
Bundle-Branch Block/diagnostic imaging , Tomography, Emission-Computed, Single-Photon , Aged , Exercise , Female , Humans , Male , Middle Aged , Sensitivity and Specificity , Technetium , Thallium Radioisotopes , Vasodilator Agents/therapeutic useABSTRACT
UNLABELLED: This study evaluated the relationship between the location of the most severe myocardial perfusion defects, the most severe coronary artery stenosis, and the site of subsequent acute myocardial infarction (AMI). METHODS: Of 3,180 patients who were admitted with a diagnosis of AMI, we identified 44 patients who had undergone previous myocardial perfusion SPECT. Thirty-one of them also had previous coronary angiography. The relationship between the location of the myocardial perfusion defects, the coronary artery stenosis, and the site of subsequent AMI was studied in these patients. RESULTS: The concordance between the location of the most severe reversible defects detected by SPECT and the site of subsequent AMI was 71% (kappa = 0.499). The concordance between the most severe stenosis detected by coronary angiography and the site of subsequent AMI was 64% (kappa = 0.451). However, kappa values for SPECT and coronary angiography were good when the interval between these investigations and subsequent AMI was <3 mo (0.724 and 0.661, respectively), for moderate to severe perfusion defects (0.719), and for 90%-99% coronary stenosis (0.626). CONCLUSION: The culprit lesion is not always the one that is manifested by the most severe reversible perfusion defect or the most critical coronary artery stenosis. Myocardial SPECT and coronary angiography can predict the location of a future AMI in 71% and 64% of patients, respectively. The percentage is higher when the interval between investigations and subsequent AMI is <3 mo, for moderate to severe perfusion defects, and for 90%-99% coronary stenosis.