Biomedical subjects
Publications and source records attributed to A T Tsygankov.
The authors examined 98 patients with different cardiovascular diseases and 20 practically healthy subjects and established that complex use of pirphotech with 99mTc-pertechnetate gives an objective information on circulatory disorders in the myocardium. Radionuclide ventriculography in the static variant should be carried out early for obtaining adequate information on the state of cardiodynamics.
The paper presents the results of examining the structural and functional parameters of the ventricles in 40 patients with ventricular tachycardia by radionuclide ventriculography on the first passage of a radioactivity bolus. Twenty patients had ventricular tachycardia resistant to antiarrhythmic agents. The patients with ventricular tachycardia were found to have systolic and diastolic dysfunction of the both ventricles. Lower pump function and higher volumetric parameters of the left ventricle in patients with refractory ventricular tachycardia concurrent with hyperkinesia of some right ventricular segments and abnormal velocity and time variables can be a criterion for resistance to antiarrhythmic agents in this group of patients.
Radiocardiography was used in 26 patients with dilated cardiomyopathy and in 20 practically healthy persons. Results revealed significant changes of the central and regional hemodynamics manifested in a reduction of the minute cardiac volume, delayed blood flow velocity, disorders of the cardioportal and cerebral hemodynamics.
Radionuclide renography and enzyme immunoassay used to evaluate renal function and renin--angiotensin--aldosterone system in 95 patients with chronic diffuse bronchitis demonstrate impairment of renal secretion and excretion in all the examinees. There are shifts in plasma renin activity and aldosterone concentration. The above defects depend on cardial--pulmonary insufficiency and respiratory--hemodynamic disorders.
The general and local ejection fractions (EF) of the left ventricle were studied in 112 patients with grade I hypertensive disease and in 20 practically healthy persons at rest and during static isometric loads. At rest general and local EF were diverse. During loads both reduction and increase of general EF were observed. Increase of general and local EF is a result of adequate physiological reaction of the myocardium while their reduction indicates limitation of the myocardial reserve of the left ventricle.
Radionuclide ventriculography was used in 145 patients with stage I and II essential hypertension and in 20 healthy persons to investigate systolic and diastolic function of the left ventricular myocardium. Quantitative analysis of myocardial function was performed on the basis of indices of total and local contractility, cardiac output, time and rate values of contraction and filling. A decrease in total ejection fraction, rate values of contraction and filling combined with increased cardiac outputs was noted in stage II essential hypertension. An exercise tolerance test in some of these patients revealed signs of the limited myocardial reserve.
Altogether 106 patients with different types of acute CHD (large and small local MI, unstable angina) and stable angina were investigated. Combined assessment of perfusion disorder permits differentiation of necrotic and ischemic myocardial lesions. A degree and type of RP accumulation corresponds to a size of necrotic myocardial lesion determined by means of biochemical markers of necrosis. Parallelism of myoglobin concentration, isoenzyme activity in the blood serum and the results of scintigraphy was revealed. In focal RP accumulation, myoglobin concentration reached maximum values; a moderate increase and decrease up to normal values in the absence of accumulation were observed in diffuse accumulation. Diffuse RP accumulation in patients with stable and unstable types of angina was indicative of transient perfusion disorders resulting from myocardial ischemia.
Explore the source record for details and available documents.
Early changes of left ventricular diastolic function were revealed in patients with various types of coronary heart disease (CHD) on determination of a maximum filling rate (FRmax) and the time of maximum filling rate (T-FRmax) on the basis of radionuclide ventriculography data. A decrease in FRmax and a tendency to an increase in T-FRmax were noted in the group of patients with chronic CHD with normal ejection fraction at rest as well as in the groups of patients with chronic CHD and lowered total ejection fraction at rest and with acute myocardial infarction. Correlation of changes in left ventricular diastolic and systolic functions (the ratio of FRmax/stroke volume) with predominant change of the former was revealed in all the examinees. A high sensitivity of FRmax and T-FRmax in the detection of change of diastolic function in CHD patients was shown.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Radionuclide (99mTc) ventriculography demonstrated a tendency to reduced ejection fraction, mean normalized systolic expulsion rate and myocardial circular fibre shortening rate of coronary patients that was proportionate to the severity of their condition. Myocardial lesion was shown to be heterogeneous and typically involve asynergic areas. As the disease progresses, the disturbance of myocardial contractility grows more severe, and the number of hypokinetic areas increases while that of normo- and hyperkinetic areas declines.
The authors described the use of radionuclide ventriculography in dynamic and static variants to determine left ventricle volumetric values. The results obtained were correlated with those of roentgeno-contrast ventriculography (the correlation coefficient R was 86.8%) and literature data on echocardiography. The end-diastolic, end-systolic and stroke volumes (EDV, ESV and SV), the mean ejection rate (MER) and the total ejection fraction (TEF) were determined in controls and patients with chronic CHD. With growing severity of disease, EDV, ESV were on the increase, whereas SV and MER were on the decrease. The determination of left ventricle volumetric values permitted improved diagnosis and differential diagnosis of cardiovascular diseases.
An analysis of physical exercise tolerance in CHD patients with the equal number of affected coronary arteries with relation to a coronary bed region involved in a pathological process, showed that its decrease was mostly pronounced in vasoconstriction of the left coronary arterial system and was determined by a decrease in the blood flow in this region.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
In 158 patients with chronic ischaemic heart disease (IHD), the state of microcirculation was investigated, using local 133Xe clearance. With growing severity of the disease, muscular blood flow decreased. Local disturbances were accompanied also by changes in central haemodynamics (decrease in cardiac index, slow-down of blood flow in the pulmonary and systemic circulations, increased peripheral resistance), which were established by radiocardiography using 131I-labelled albumin. A distinct relationship was found between muscular blood flow and the intensity of intravascular microcirculatory disturbances (microthrombosis, intravascular thrombocyte aggregation, arteriolo-venular anastomoses). The authors recommend the use of 133Xe clearance for microcirculation study in patients with chronic IHD.