[Repeated Coronary Artery Bypass Surgery 18 Years After the Primary Revascularization of Myocardium in a Patient With Acute Coronary Syndrome Without the Segment ST Elevation].

This article describes a clinical case of successful repeated coronary bypass grafting 18 years after the initial surgery in a patient with non-ST-elevation acute coronary syndrome.

Association of coronary microvascular dysfunction and cardiac muscle injury in acute myocardial infarction: results of comparison of dynamic SPECT and cardiac MRI.

Aim      To study the interrelation of changes in coronary microcirculation by data of dynamic single photon emission computed tomography (SPECT) and myocardial injury by data of magnetic resonance imaging (MRI) in patients with acute myocardial infarction (AMI).Material and methods  The study included patients admitted to the emergency cardiology department with new-onset AMI. Contrast-enhanced cardiac MRI was performed for all patients on day 2-7 of admission. Dynamic SPECT of the myocardium with evaluation of semiquantitative and quantitative parameters of perfusion was performed on day 7-10.Results All patients were divided into two groups based on the type of MR contrast agent accumulation: 1) patients with the ischemic type of contrast enhancement (n=34; 62 %); 2) patients with the non-ischemic type of contrast enhancement (n=21; 38 %). According to data of myocardial perfusion scintigraphy (MPS), the group of ischemic MR pattern had larger perfusion defects at rest and during a stress test. Moreover, this group was characterized by lower global stress-induced blood flow and absolute and relative myocardial flow reserve (MFR). When the study group was divided into patients with transmural (n=32; 58 %) and non-transmural (n=23; 42 %) accumulation of the MR-contrast agent, lower values of global stress-induced blood flow and of absolute and relative MFR were observed in the group of transmural MR-enhancement pattern. A moderate inverse correlation was found between the stress-induced myocardial blood flow and the volume of myocardial edema (r= -0.47), infarct area (r= -0.48) and microvascular obstruction area (r= -0.38).Conclusion      The variables of dynamic SPECT characterizing microcirculatory disorders that are independent on or due to injuries of the epicardial coronary vasculature reflect the severity and depth of structural changes of the myocardium in AMI. In this process, quantitative variables of myocardial perfusion are interrelated with the myocardial injury more closely than semiquantitative MPS indexes. The findings of the present study can also contribute to the heterogenicity of a patient group with acute coronary syndrome and AMI. Further study is required for understanding the prognostic significance of dynamic SPECT parameters.

[State of the art mathematical methods of the coronary blood flow modelling: background and clinical value].

X-ray computed tomography coronary angiography (CTCA) is a current method for diagnosing ischemic heart disease. Although this method has a high specificity and a negative predictive value in diagnosing coronary obstructions, there are limitations in determining the hemodynamic significance of the stenosis. Extensive use of noninvasive methods for evaluation of coronary hemodynamics, specifically evaluation of the fractional flow reserve (FFR) is limited due to its high cost and risks of complications. Mathematical modeling of coronary circulation and its reserve based on CTCA data is an up-to-date method that has been experimentally confirmed and clinically validated. This method showed a high diagnostic efficacy in several large studies that used the invasive determination of FFR as a "gold standard". This review addresses the current state of studies on mathematical modeling for fractional coronary reserve in patients with ischemic heart disease, as well as the limitations and prospects of this method.

Method for Studying the Myocardial Blood Flow Reserve by Load Dynamic Single-Photon Emission Computed Tomography.

We developed a method for collection and processing of scintigraphic data to estimate myocardial reserve in a gamma-chamber with cadmium-zinc-telluride detectors. Dynamic single-photon emission computed tomography of the heart with (99m)Tc-Technetril was performed in 16 coronary heart disease patients at rest and during pharmacological load. During data processing, regions of interest from the cavity and the myocardium of the left ventricle were formed and activity-time curves were constructed. The index of myocardial blood fl ow reserve was calculated as the difference between two ratios of the mean gamma-count from the myocardial area to the area under the left ventricle cavity curve (peak) during load and at rest. The mean indices of myocardial reserve in healthy volunteers and patients with coronary artery atherosclerosis were 1.86 (1.59; 2.20) and 1.39 (1.12; 1.69), respectively. The development of the method for studying myocardial reserve by single-photon emission computed tomography is an urgent problem and requires further investigations.

[Dynamic single-photon emission computed tomography as a method of identification of multivessel coronary artery disease].

Objective: The aim of this study was to determine the informative value of dynamic tomoscintigraphy in detection of multivessel coronary artery disease (CAD). Material and Methods: Patients with multivessel CAD (n= 16) and healthy volunteers (n= 9) underwent dynamic cardiac single photon emission computed tomography with 99mТс-MIBI at rest and during pharmacological stress-test. Processing of acquired results involved the formation of regions of interest from the cavity and the myocardium of the left ventricle used to create activity-time curves. Coronary flow reserve index was defined as a quotient of two ratios of the mean counts from the myocardial region to the integral activity in the left ventricular cavity for the studies performed during pharmacological stress test and at rest. Results: The mean values of coronary flow reserve index were 1.86 (1.59; 2.2) in group of healthy volunteers and 1.39 (1.12; 1.69) in patients with multivessel CAD. When the value of this index was less than 1.77, the method allowed for detection of three-vessel CAD with the sensitivity and specificity rates of 81.8% and 66.7%, respectively. Conclusion: Performing the standard myocardial perfusion scintigraphy in combination with the method of coronary flow reserve index assessment allows for enhancement of the diagnostic value of scintigraphic approach in the evaluation of coronary circulation disturbances in multivessel CAD.