METHOD FOR DIAGNOSING MYOCARDIAL ISCHEMIA BY VOLUMETRIC COMPUTED TOMOGRAPHY IN COMBINATION WITH PHARMACOLOGICAL TEST OF ADENOSINE TRIPHOSPHATE Russian patent published in 2020 - IPC A61B5/00 A61B5/02 A61K31/7076 A61B6/02 

FIELD: medicine.

SUBSTANCE: invention relates to the field of medicine, namely to cardiology. Myocardial perfusion is analyzed by volumetric computed tomography (VCT), with pharmacological breakdown of sodium adenosine triphosphate (ATP), which is performed in two stages. At the first stage, the examination is carried out at rest with introduction of a contrast agent. At the second stage - not less than 20 minutes after the first introduction of the contrast preparation, the study is carried out in a stress state which is induced by infusion through a peripheral venous catheter of 1 % ATP solution at rate of 0.10–0.20 mg/kg in minute for 1–5 minutes. At the same time from the beginning of infusion of ATP or when the criteria for stopping the pharmacological test, such as the occurrence of retrosternal pains and/or ischemic ECG dynamics, without interrupting the infusion, 60–90 mg of a non-ionic iodine-containing contrast preparation with concentration of 350–370 mg of iodine/ml is introduced intravenously bolus at rate of 4–5 ml/s. At the same time at the first and second stages prior to the introduction of the contrast preparation, a natural examination is carried out, all stages of the VCT are necessarily performed with prospective synchronization with the ECG in the diastole phase, where the trigger is set for 65–93 % of the cardiac cycle phase. ECG electrodes are applied so that they are outside the field of the projection of the heart with the possibility of excluding artefacts from them in the left ventricular myocardial perfusion assessment zone. At the second stage, additional blood pressure control is performed, and as a result of the VCT, tomographs are taken without artifacts from LV motion, which characterize at least one phase of the cardiac cycle, at least 360 sections. Weakening of the myocardial density (MD) is determined on the basis of which the following values are calculated: a contrast index (CI) as a relation of myocardial infarction on the entire section to an MD of the subendocardial segment with reduced contrast enhancement. That is followed by determining the myocardial perfusion reserve (MPR), which is calculated as the ratio of infrared rest to infrared load. If the MPR value ≤ 0.7 is the presence of left ventricular myocardial ischemia.

EFFECT: method enables diagnosing left ventricular myocardial ischemia with varying degrees of coronary artery changes, avoiding multiple-stage examination of patients, more accurate diagnosis verification for the purpose of timely drug-induced intervention and improved patient's prognosis.

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