Rest Myocardial Perfusion Scintigraphy Research Articles

Utilidad de la gammagrafía de perfusión miocárdica para la evaluación de pacientes con dolor torácico en el servicio de urgencias

Objective To evaluate diagnostic efficacy of rest myocardial perfusion scintigraphy in the detection of acute coronary syndrome in patients with chest pain and non diagnostic electrocardiogram, comparing it with reference techniques, in Emergency Department. Material and methods Myocardial perfusion scintigraphy was carried out in 40 patients with those defined characteristics in the Emergency Department, administering the radiopharmaceutical in the next 6 hours after the pain was over. All subjects followed routine diagnostic and treatment management. Final diagnosis of coronary disease was established by coronariography and/or stress perfusion myocardial scintigraphy. Patients were followed up for 9-12 months. Results Myocardial perfusion scintigraphy showed a negative predictive value of 96,15 % (CI 95 %: 86.84-100.00). The main limitation of its application was breast and diaphragmatic attenuation phenomenon, given that correction algorithms were not available. Global kappa coefficient was 0.78 when to compared interobserver agreement. Conclusion Rest myocardial perfusion scintigraphy is a safe and efficient test in the screening of patients with chest pain suggestive of angor with non-diagnostic ECG in Emergency Department, and also provides prognostic information and risk stratification.

Utility of myocardial perfussion scintigraphy in emergency department for evaluation of patients with chest pain

Objective To evaluate diagnostic efficacy of rest myocardial perfusion scintigraphy in the detection of acute coronary syndrome in patients with chest pain and non diagnostic electrocardiogram, comparing it with reference techniques, in Emergency Department. Material and methods Myocardial perfusion scintigraphy was carried out in 40 patients with those defined characteristics in the Emergency Department, administering the radiopharmaceutical in the next 6 hours after the pain was over. All subjects followed routine diagnostic and treatment management. Final diagnosis of coronary disease was established by coronariography and/or stress perfusion myocardial scintigraphy. Patients were followed up for 9-12 months. Results Myocardial perfusion scintigraphy showed a negative predictive value of 96,15 % (CI 95 %: 86.84-100.00). The main limitation of its application was breast and diaphragmatic attenuation phenomenon, given that correction algorithms were not available. Global kappa coefficient was 0.78 when to compared interobserver agreement. Conclusion Rest myocardial perfusion scintigraphy is a safe and efficient test in the screening of patients with chest pain suggestive of angor with non-diagnostic ECG in Emergency Department, and also provides prognostic information and risk stratification.

Left ventricular function parameters obtained from gated myocardial perfusion SPECT imaging: a comparison of two data processing systems

The Cedars-Sinai Quantitative Gated Single Photon Emission Computed Tomography (SPECT) (QGS) program, used to quantify left ventricular function parameters from gated myocardial perfusion scintigraphy (MPS), has been extensively validated and compared with other methods of quantification. However, little is known about the reproducibility of QGS on different processing systems. This study compared the findings of QGS running on workstations provided by two different manufacturers. Gated rest MPS studies of 50 patients were analysed retrospectively. Filtered back-projection (FBP) was performed using identical parameters on Philips Pegasys and Nuclear Diagnostics Hermes workstations to produce gated short-axis (SA) slices. In addition, the gated SA slices reconstructed on the Pegasys were transferred to the Hermes. QGS was used to calculate the end-diastolic volume (EDV), end-systolic volume (ESV) and left ventricular ejection fraction (LVEF) in each case. The mean+/-standard deviation differences between the Pegasys and Hermes function parameters were -7.06+/-3.91 ml (EDV), -5.54+/-3.21 ml (ESV) and +1.14%+/-1.43% (LVEF) when data were reconstructed on different systems, and -0.16+/-1.58 ml (EDV), -0.10+/-1.02 ml (ESV) and +0.14%+/-0.73% (LVEF) when data were reconstructed on the same system. Bland-Altman plots showed definite trends for EDV and ESV for data reconstructed on different systems, but no trends were seen for data reconstructed on the same system. When data were reconstructed on two separate systems, the difference between the function parameters obtained from Pegasys and Hermes could be ascribed to differences in the reconstruction process on each system despite the use of identical parameters (filters, etc). However, when the same reconstructed data were analysed on both systems, no significant difference in left ventricular function parameters was observed.

The significance of stress-induced ST segment depression in patients with inferior Q wave myocardial infarction

OBJECTIVESThis study was conducted to evaluate the relationship between ST segment depression (STD) during dobutamine stress tests in different electrocardiogram (ECG) leads and myocardial ischemia assessed by simultaneous single photon emission computed tomography (SPECT) imaging in patients with inferior Q wave myocardial infarction.BACKGROUNDSTD is a standard electrocardiographic sign of myocardial ischemia. Although STD may represent reciprocal changes in patients with previous myocardial infarction, studies of reciprocal changes during stress tests are scarce.METHODSDobutamine (up to 40 μg/kg/min) stress and rest myocardial perfusion scintigraphy using technetium SPECT imaging was performed in 125 patients >3 months after Q wave inferior myocardial infarction. The location of STD at the ECG was defined as anterior (V1–4), high lateral (I, aVL) and lateral (V5,6). Ischemia was defined as reversible perfusion abnormalities.RESULTSSTD occurred in the high lateral leads in 20 patients, in the anterior leads in 12 patients and in the lateral leads in 2 patients. ST segment elevation occurred in 25 patients in the inferior leads. High lateral STD was associated with inferior ST elevation in 16 patients (80%). There was a significant inverse linear correlation between the magnitude of ST segment shift from rest to peak stress in the inferior and the high lateral leads (r = −0.8, p < 0.0005), whereas no significant correlation was found between ST segment shift in the inferior and the anterior leads (r = −0.1, p = NS) or between the inferior and the lateral leads (r = 0.15, p = NS). Ischemia was detected in 45% of patients with and in 42% of patients without high lateral STD (p = NS). Patients with high lateral STD had a higher prevalence of fixed perfusion defects in the inferior wall (100% vs. 70%) and in the posterolateral wall (55% vs. 29%) compared with other patients (both p < 0.05). Ischemia was more prevalent in patients with anterior STD than without (75% vs. 39%, p < 0.05).CONCLUSIONSIn patients with inferior Q wave myocardial infarction, stress-induced STD in high lateral leads should be recognized as a reciprocal change for ST elevation in the inferior leads, and therefore, should be interpreted with the consideration of the significance of ST elevation if present, rather than being indicative of myocardial ischemia on its own. The STD found in the anterior leads appears to be a sign of myocardial ischemia. These findings should be considered in the definition of a positive ECG stress test and in establishing the criteria for the termination of stress test.