Single photon emission computed tomography to assess myocardial perfusion in suspected ischemic heart disease

Abstract

The objective of the study is to analyze the usefulness of single photon emission computed tomography (tomogammagraphy) to assess myocardial perfusion in patients with suspected ischemic heart disease, at the Lenin Fonseca School Hospital, between February 2018 and July 2021. Material and method: Observational, descriptive, correlational, retrospective, cross-sectional study. The study population was 52 patients, selected according to the census criteria. The Kappa-Cohen concordance index statistical test was applied, between electrocardiography and tomogammagraphy in the detection of myocardial ischemia. Results: The age group of 40-59 years was the most frequent with 29 (56%). There were 27 women (52%). Chronic arterial hypertension was the most common comorbidity with 31 (60%). Chest pain was the most common indication with 48 (92%). Complete block of the left bundle branch of His was the most frequent baseline electrocardiographic finding with 7 (13%). Pharmacological stress was the most used technique in 29 patients (56%), with an average time of 6-9 minutes in 49 (94%). Six patients (11%) presented ischemia by electrocardiography and 12 (23%) by tomography. The Kappa-Cohen concordance index between electrocardiography and tomogammagraphy was 0.343 (low concordance), (p=0,007). Conclusions: Tomogammagraphy detected a higher proportion of ischemia than electrocardiography, especially in pre-existing bundle branch block, in whom it was not possible to detect ischemia by electrocardiography, so the low concordance between both diagnostic tests was statistically significant. Therefore, the research hypothesis is confirmed and the null hypothesis is rejected.

Keywords: Scintigraphy, cardiac ischemia, cardiac tomogammagraphy, single photon emission computed tomography.