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Evaluation of the SPECT radioisotope perfusion scan in the detection of ischemic heart disease

Zdanowski Paweł, Cacko Marek, Rabczenko Daniel, Kochman Janusz, Królicki Leszek

Inżynier i Fizyk Medyczny

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2022

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Vol. 11, nr 2

129--135

EN

Objectives: The aim of the study is to determine the diagnostic value of myocardial perfusion scintigraphy (MPS) depending on the location and size of stenosis of a coronary vessel or vessels. Methods: Results of examinations of patients hospitalized in two hospital departments of the same medical facility were analyzed. Retrospective research material consisted of results obtained for 200 patients with suspected ischemic heart disease (coronary artery disease - CAD). From this group, 83 examinations were selected where results of coronary angiography and perfusion scintigraphy (MPS) were available. The following tests were used for statistical studies: t-Student, Chi2, Fisher- -Sendecor, Kruskal-Wallis and Willcoxon. The use of these tests allowed for: – determination of predictive factors favoring development of ischemic heart disease in the analyzed group of patients, – determination of sensitivity and specificity of MPS, taking the coronary examination as the “gold standard”, – assessment of usefulness of the MPS imaging depending on location of a stenosis within the main coronary vessels, – evaluation of usefulness of MPS in detection of a multivessel disease. Results: I n t he a nalyzed g roup o f p atients, a rterial h ypertension was the main factor predisposing to CAD (p = 0.016). The highest sensitivity of MPS in the diagnosis of ischemia was found in the group of patients with stenosis of the right coronary artery (RCA) (p = 0.029) and the circumflex (Cx) and marginal (MB) branches (p = 0.028). A comparative analysis was performed between the degree of narrowing of the above vessels and the degree of perfusion disorders in the MPS study. There was a correlation between the severity of ischemia in MPS and the degree of stenosis in both RCA (p = 0.011, 95% sensitivity (83.1 - 99.4 CI; negative predictive value 83.3%) and the Cx/MB complex (p = 0.044, sensitivity 94.7% ( 83.1 - 99.4 CI), negative predictive value - 83.3%). There was a correlation between the result of the MPS perfusion scan and disease of two or three coronary vessels. There was a 97% agreement between the presence of permanent or transient defects in MPS and the presence of stenosis in 2 or 3 coronary vessels exceeding 80% of the vessel lumen. In the group of patients with stenosis ranging between 50-80%, abnormal results of the MPS occurred in 41.7% of patients. Conclusion: The results confirm that myocardial perfusion scintigraphy is a very valuable screening test in patients with suspected CAD. This examination shows high sensitivity also in the group of patients with multivessel disease.

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Experimental study and modelling the evolution of viscoelastic hysteresis loop at different frequencies in myocardial tissue

Smoluk A., Smoluk L., Lisin R., Protsenko Y.

Acta of Bioengineering and Biomechanics

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2017

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Vol. 19, no. 3

11--17

EN

Our work involved experimental study of the influence of actomyosin complexes and the main structural components of the myocardial tissue – connective tissue collagen framework and cardiomyocytes – on the characteristics of viscoelastic hysteresis at different frequencies. In this paper a new method was introduced for the analysis of the viscoelastic characteristics of the force hysteresis in the isolated myocardial preparation for the assessment of mechanical energy expenditure in the tension-compression cycle. We established that basic myocardial structures have an impact on the to the characteristics of the viscoelastic hysteresis in many ways. It was shown that in rat’s myocardium cardiomyocytes one main factor that define the stiffness and viscosity of the myocardium in the physiological range of deformations, while binding of calcium ions with EGTA and calcium removal of sarcoplasmic reticulum with caffeine reduces viscoelasticity by ~30% and collagen framework is responsible for about 10% of viscoelasticity. It was revealed that in the physiological range of the hysteresis frequencies (3 to 7 Hz) expenditure of mechanical energy per unit of time increases linearly with increasing frequency. We proposed the structural and functional model that adequately describes the characteristics of the viscoelastic hysteresis in myocardial preparation in the range of strains and frequencies being under study.

3

System przygotowania i doprowadzenia płynu niskotemperaturowego do zabiegu krioablacji mięśnia sercowego

Dobka E.

Technika Chłodnicza i Klimatyzacyjna

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2014

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nr 8-9

312--318

PL

Artykuł jest kontynuacją opublikowanego w numerze 6-7/2014 „TCHK” opracowania autorki poświęconego wykorzystaniu techniki chłodniczej w zabiegu krioablacji w leczeniu arytmii serca. W tej publikacji na wstępie przedstawione zostały przykładowe, dostępne na rynku urządzenia przeznaczone do wykonywania takich zabiegów. Istotnym zagadnieniem są przedstawione wyniki modelowania rozkładu temperatur w tkance sercowej podczas omawianego zabiegu. Zasadniczym elementem artykułu jest prezentacja autorskiej koncepcji systemu przygotowania i doprowadzenia płynu niskotemperaturowego do kriosondy wraz z wybranymi obliczeniami cieplnymi układu. Prezentowany system składa się z dwóch obiegów: obiegu otwartego w którym przepływa podtlenek azotu i zamkniętego obiegu chłodniczego z czynnikiem R404A, dochładzającego wstępnie ciecz kriogeniczną do wymaganej temperatury.

EN

This article is a continuation of the published in the issue 6-7 / 2014 "TCHK" dedicated to the development of the author's use of refrigeration in the cryoablation in the treatment of cardiac arrhythmias. In this publication are presented at the beginning of the sample, commercially available equipment designed to perform such procedures. Another important issue are presented the results of modeling of the temperature distribution in the tissue of the heart during the procedure in question. An essential element of this article is to present an original concept of the system of preparing and supplying fluid to the cryoprobe low temperature together with selected thermal calculations of the system. The present system comprises two circuits: the open circuit wherein the flow of nitrous oxide and the closed-loop refrigerant R404A, dochładzającego pre cryogenic liquid to the desired temperature.

4

Viscoelastic properties of the papillary muscle: experimental and theoretical study

Smoluk L., Protsenko Y.

Acta of Bioengineering and Biomechanics

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2012

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Vol. 14, no. 4

37-44

EN

It is well known that the structure of biological tissue is closely related to tissue functions and defines its viscoelastic properties. It is necessary to create a model combining structural organization of myocardium and its viscoelastic properties to develop a model of cardiac wall of intact or deceased heart. This paper is devoted to experimental and theoretical study of viscoelastic behavior of isolated myocardial samples. A three-dimensional structural-functional model of papillary muscle is presented. The model adequately describes nonlinear viscoelastic behavior of isolated papillary muscles under uniaxial strain both in static condition and under dynamic loading.