[Radionuclide Methods in the Assessment of Anthracycline-Induced Cardiotoxicity].

PURPOSE: To compare diagnostic efficacy of multigated acquisition (MUGA) scan and Tc-99m MIBI gated SPECT for evaluation and forecast of anthracycline-induced cardiotoxicity. MATERIAL AND METHODS: We included into this study 80 patients (72 women and 8 men, mean age 43 ± 4.2 years) with malignant tumors without overt pathology of the cardiovascular system. These patients received doxorubicin (50 mg/m2 per course) based cytostatic therapy. All patients were studied either by MUGA (n = 40) or 99MTc MIBI gated SPECT (n = 40) before initiation of chemotherapy 1 hour after first administration of doxorubicin and after the 4th course. RESULTS: After administration of 50 mg/m2 of doxorubicin 14 patients according to MUGA scan and 16 patients according to 99mTc MIBI gated SPECT had significant (≥ 10%) reduction of left ventricular ejection fraction (LVEF). Significant inhibition of systolic function in these patients remained after the 4th course of treatment. Individual analysis of the MUGA and 99mTc MIBI gated SPECT data registered after the fourth course (achievement of total doxorubicin dose of 200 mg/m2) showed that ≥ 10% LVEF reduction in response to the first dose of doxorubicin could predict the development of cumulative cardiotoxicity. CONCLUSION: MUGA scan and 99mTc MIBI gated SPECT can be applied with equal effectiveness for assessment of acute and chronic anthracycline-induced cardiotoxicity in patients with malignant tumors. LVEF reduction ≥ 10% in response to the first dose of doxorubicin appeared to be a predictor of development of chronic cardiotoxicity.

[Gamma-scintigraphy in assessment cardioresynchronizing therapy at chronic heart failure].

The purpose of the work was to study influence of cardioresynchronizing therapy (CRT) on systolic and diastolic myocardial function with the aid of radionuclide methods. 19 patients (9 women) at the age from 21 to 72 years (average age 55.4 +/- 8.3 years) with NYHA class III - IV cardiac insufficiency, dilated cardiomyopathy (n = 14) and ischemic cardiomyopathy (n = 5) were included in the study. Radionuclide angiopulmonography and balanced radionuclide ventriculography were performed by standard method before CRT, in 20 - 30 days and in 12 - 18 months. In 20 - 30 days after CRT significant increase in stroke volume and stroke index, ejection fraction and part of circular fibers contraction was detected, which confirmed improve in systolic heart function. In 12 - 18 months significant increase in maximal filling rate index, filling fraction of 1/3 and 2/3 of diastole was noted, which reflected improve of left ventricle diastolic function. Recovery of myocardial contraction synchronism leaded to rehabilitation of normal pulmonary microcirculation. Radionuclide examination methods as high-informative modes of combine assessment of heart contractile function and pulmonary circulation in CRT dynamics are described. CRT, improving systolic and diastolic myocardial functions, has positive influence on pulmonary hemodynamics in patients with chronic heart failure.

[Scintigaraphic assessment of viability of the ischemic myocardium while carrying out nitroglycerine-mediated and orthostatic tests].

The work deals with diagnostic possibilities of single photon emission computed tomography (SPECT) of the heart and ECG-synchronized planar scintigraphy (ECG-PS) with 99mTc-tetrophosmine used to determine viability of the ischaemic myocardium in patients presenting with postmyocardium infarction cardiosclerosis. A total of 20 patients diagnosed with Ischaemic heart disease (IHD), functional class III-IV angina of effort, postmyocardium infarction cardiosclerosis were examined. All the patients underwent SPECT of the heart with 99mTc-tetrophosmine, which was carried out at rest and on the background of sublingual administration of nitroglycerine, as well as planar ECG-synchronized scintigraphy of the myocardium according to the protocol: rest - nitroglycerine-mediated - orthostatic tests. Repeat examinations at rest were performed 4-6 weeks after the coronary artery bypass (CAB). The obtained findings showed that sensitivity of perfusion SPECT with 99mTc-tetrophosmine of the myocardium amounted to 85%, specificity to 76%, and diagnostic accuracy to 82%. Calculating the diagnostic parameters of perfusion while using ECG-PS with sublingual administration of nitroglycerine demonstrated that sensitivity of the method amounted to 71%, specificity to 91%, and diagnostic accuracy to 83%. Analyzing the orthostatic test yielded sensitivity equalling 72%, specificity - 84% and diagnostic accuracy - 81%. Sensitivity of assessing myocardial contractility by means of ECG-PS using nitroglycerine amounted to 83%, with specificity of 86% and diagnostic accuracy of 85%. At the same time, sensitivity of the orthostatic test amounted to 80%, specificity to 92%, and diagnostic accuracy to 88%. Hence, carrying out SPECT and ECG-synchronized planar scintigraphy of the heart with 99mTc-tetrophosmine on the background of sublingual administration of nitroglycerine and the orthostatic test makes it possible to simultaneously assess the reserve of myocardial contractility and perfusion, thus strongly suggesting a high informative value of the techniques involved in detecting myocardial viability in patients with postmyocardium infarction cardiosclerosis.

[The antianginal action of calcium antagonists: the results of instrumental examination and their clinical assessment]. / Antianginal'noe deistvie antagonistov kal'tsiia: rezul'taty instrumental'nogo obsledovaniia i ikh klinicheskaia otsenka.

In 88 patients with coronary heart disease and stable exercise-induced angina pectoris, the efficiency of calcium antagonists was examined by using myocardial Tl-199 scintigraphy and comparing its data with the parameters of angiography and their intracoronary injection. Three types of therapy-induced changes in myocardial perfusion were identified, which were as follows: 1) significant decreases in hypoperfusion area dimensions; 2) no changes in scintigraphic parameters, and 3) clinically asymptomatic increases in the number of hypoperfused sectors. There was a relationship between the therapy-induced changes and the number of sclerotic arteries though the ability of large coronary vessels to dilate was substantially decreased, as shown by angiopharmacological studies.

[The importance of the noninvasive scintigraphic assessment of pulmonary arterial pressure in persons who have had an acute myocardial infarct]. / Znachenie neinvazivnoi stsintigraficheskoi otsenki legochnogo arterial'nogo davleniia u lits, perenesshikh ostryi infarkt miokarda.

Twenty-two patients with a history of acute myocardial infarction underwent pulmonary perfusion scintigraphy at rest and during bicycle exercise testing. 99mTc-labelled human albumin microspheres were used. The perfusion ratio in the upper and lower pulmonary regions (U/L ratio) was calculated from scintigraphic findings. There was a close correlation between mean pulmonary blood pressure and U/L ratio (r = 0.95). It was established that the absence of microcirculatory bed reserve scintigraphically revealed in the lesser circulation in patients with prior myocardial infarction may be considered to be a negative predicator.

[199Tl chloride in the experimental assessment of myocardial perfusion. 2]. / 199Tl-khlorid v otsenkie perfuzii miokarda v ésperimente. Soobshchenie 2.

Pharmacokinetic and scintigraphic studies on 199Tl were conducted. Pharmacokinetic characteristics of 199Tl chloride give an opportunity to use it for perfusion scintigraphy of the myocardium which is no inferior in the resolving power to 201T1. The shorter half-life of 199Tl will make it possible to reduce radiation exposure of an examinee.