ABC | Volume 114, Nº2, February 2020

Update Update of the Brazilian Guideline on Nuclear Cardiology – 2020 Arq Bras Cardiol. 2020; 114(2):325-429 Table 17 – Serious adverse events related to cardiovascular stress methods (rate of events observed per 1,000 individuals) 79 Serious events ET Dobut Dipy Aden Regad Any event 0.1 - 3.46 2.988 0.714 - 2.6 0.97 CR Death 0 to 0.25 CR 0.5 CR CR VF/VT 0 to 25.7 0.6 - 1.35 NR NR NR AMI 0.038 0.3 - 3 1 0.108 CR Cardiac rupture Unk CR NR NR NR High-grade AVB / ASY Unk NR CR CR CR Bronchospasm Unk NR 1.5 0.76 CR Stroke/TIA Unk CR NR NR CR AF Unk 5 - 40 NR NR CR Seizure Unk CR NR 1.5 CR Aden: adenosine; AVB: atrioventricular blockage; AF: atrial fibrillation; AMI: acute myocardial infarction; ASY: asystole; CR: case report; Dipy: dipyridamole; Dobut: dobutamine; ET: exercise testing; NR: not reported; Regad: regadenoson; TIA: transient ischemic attack; Unk: Unknown; VF/VT: ventricular fibrillation/ventricular tachycardia. the short, long vertical, and long horizontal axes (Figure 9). Characterization of uptake of the radiopharmaceutical MIBI- 99m Tc or Tetrofosmin- 99m Tc during both exam stages (resting and stress, 1 day protocol) and thallium-201during the stress and redistribution phases focuses on the anterior, septal, inferior , lateral, and apical regions of the LV (Figure 9). The short-axis projection uses transverse tomographic slices of the LV, sweeping from the apex or distal portion, through the middle of the cavity, to the basal portion. All regions and subdivisions are numerically identified, in accordance with the established scoring system, with the aim of standardizing segmentary analysis of the LV myocardium for perfusion study. Division into 17 segments has consensually been accepted, resulting in less interpretation subjectivity (Figure 10 and Table 18). Different radiopharmaceutical uptake and retention patterns allow for differentiation of normal, ischemic, and fibrotic tissues. The normal myocardium has similar uptake during both the stress and resting/ redistribution phases, whereas the ischemic myocardium shows reduced relative uptake in stress images and normal uptake during resting/redistribution. Fibrotic tissue, on the other hand, shows reduced relative uptake during both study Figure 8 – Effects of different types of stress methods on coronary flow elevation and values reached during maximum hyperemia. Baseline: resting coronary flow, 1 ml.min.g-1; Exercise: reaching values 2.5 to 3.5 times baseline coronary flow value; Dobut (dobutamine): reaching values around 2.0 to 2.5 times baseline coronary flow value; Dipy (dipyridamole) and Aden (adenosine): reaching values as high as 5.0 times baseline coronary flow value. 28 Coronary Flow during Maximum Hyperemia ml/min/g Baseline Exercise Dobut Dipy Aden 345