[Radiodiagnostic studies in atherosclerosis]

Due to the fact that it is necessary to make a detailed assessment of the implication of atherosclerotic lesion in the development of coronary heart disease and to timely detect the instability of the process, there is a need for developing new methods for imaging atherosclerosis. Coronary angiography and radionuclide studies are known to be of importance in the diagnosis of atherosclerosis. Of particular interest is combined positron emission and X-ray tomography using 18FDG, which determines not only the site and degree of an atherosclerotic process, but also its activity.

[Prediction of results of antiarrhythmic drug therapy in patients with malignant ventricular tachyarrhythmias, based on the prognostic value of left ventricular contractility parameters]

In 44 patients (3 women and 41 men, mean age 54 +/- 11 years) with malignant ventricular tachyarrhythmias (MVT) we assessed dependence of results of testing of antiarrhythmic drugs and efficacy of their long term use for prevention of recurrences of MVT on topography of derangement of local left ventricular (LV) contractility. Regional LV contractility was assessed with transthoracic echocardiography and radionuclide ventriculography (RNV). Testing of antiarrhythmic drugs was performed under control of repetitive intracardiac electrophysiological studies. Duration of follow-up was 28 (13 - 61) months. According to ROC-analysis most precise markers of positive results of drug testing were values of local ejection fraction (EF) in apical LV segment (10th segment on RNV) above 55%. Signs predisposing to absence of MVT recurrences during long term use of antiarrhythmic drugs were lack of mitral regurgitation (above I degree) according to echocardiography data, values of local EF in segment of lateral LV wall (4th segment on RNV) exceeding 42%, or value of LV end diastolic volume less than 365 ml according to RNV data. Parameters of local LV contractility are most precise markers of results of the use of antiarrhythmic drugs in patients with MVT, their diagnostic value is hair than that of global LVEF. Efficacy of antiarrhythmic drugs at electrophysiologic testing and long term follow-up are associated with different parameters of local LV contractility.

[The role of noninvasive methods of investigation in diagnosis of atherosclerosis]

Visualization of the myocardium with the use of various high technologies gains more and more important significance in diseases of cardiovascular system. Large value for investigations of the heart and blood vessels have acquired methods of echocardiography, magnetic resonance tomography, spiral computed tomography, as well as large spectrum of methods of nuclear cardiology. Contemporary value of instrumental methods of investigation for diagnostics of atherosclerosis is discussed in this paper and diagnostic possibilities of various techniques for assessment of the state of myocardium, pathological changes of vascular wall and for visualization of atherosclerotic plaques (AP) are presented. Advantages and drawbacks of methods, their complex application for objective analysis of changes in AP and their clinical significance are considered. Special accent is made on early diagnosis of pathological derangements, because full value information allows making adequate decisions about subsequent curative measures. It is shown that detection and evaluation of early signs of atherosclerosis appears to be determining factor of efficacy of treatment. In patients without obvious symptoms of ischemic heart disease or at the background of postinfarction cardiosclerosis nuclear cardiology with assessment of myocardial perfusion by single photon emission computed tomography and positron emission tomography (PET) appears rather valuable for assessment of viability even when coronary arteries are unchanged. Important significance for detection of cardiosclerosis has also acquired spiral computed tomography, which allows to reveal calcium in blood vessels. The use of multislice computed tomography in perspective might partially replace coronary angiography especially for assessment of degree of stenoses and patency of grafts. On initial stages of atherosclerosis information on AP structure especially on the presence of inflammatory component is very important. Definite successes become noticeable with application of magnetic resonance tomography for detection of AP. However, probably, further perfection of equipment and methodological approaches with the use of novel contrasts is necessary. In this plane definite successes are achieved by PET and combined examinations by methods of PET/CT integrating advantages of both techniques.

[Myocardial contractility evaluation by radionuclide 4D-tomoventriculography in patients with ischemic heart disease]

AIM

To estimate the capabilities of the new technique radionuclide 4D-tomoventriculography (4D-RTVG) versus conventional methods, such as radionuclide equilibrium ventriculography (REVG), ECG-synchronized single photon emission computerized tomography (SPECT), and echocardiography (EchoCG), in the evaluation of systolic and diastolic dysfunction in patients with coronary heart disease (CHD).

MATERIALS AND METHODS

The study included 29 patients (19 males and 10 females) aged 43 to 66 years who had CHD. The diagnosis of CHD was established on the basis of coronary angiographic findings when the signs of coronary atherosclerosis were found. All the patients underwent 4D-RTVG, REVG, myocardial ECG-synchronized SPECT, and Echo CG.

RESULTS

There was a strong correlation of the values obtained by 4D-RTVG versus REVG and EchoCG when ejection fraction and left ventricular (LV) end-diastolic volume and the indices reflecting LV blood filling and ejection velocity were estimated. The correlation between the values provided by 4D-RTVG and myocardial ECG-synchronized SPECT females was slightly weaker.

CONCLUSION

The findings suggest that 4D-RTVG is highly reliable in evaluating both LV systolic and diastolic functions. That fact the technique is easy-to-use and mini-invasive shows that it may be clinically applied.

[Study of the impact of intramyocardial implantation of stem cells on myocardial perfusion and contractility in patients with coronary heart disease concurrent with postinfarct cardiosclerosis and chronic heart failure]

OBJECTIVE

to study of intramyocardial implantation of cultured bone marrow stem cells on myocardial perfusion and contractility in the surgical treatment of patients with coronary heart disease (CHD) and chronic heart failure (CHF), by synchronized single-photon emission computed tomography (SSPECT) of the myocardium.

SUBJECTS AND METHODS

The study included 11 patients. Intramyocardial injection of cell injections into the myocardial periscarring areas was made at coronary bypass surgery. All the patients underwent 99mTc myocardial SSPECT MIBI before and 3, 6, 12 months after surgery.

RESULTS AND CONCLUSIONS

Implantation of bone marrow stem cells into the left ventricular myocardium favorably affects left ventricular remodeling and contributes to the improvement of myocardial perfusion and contractility, as evidenced by 99mTc.

[Imaging of inflammatory foci with 99m technecium labeled antimicrobial oligopeptide]

A direct method using 99mtechnecium to label the synthetic antimicrobial oligopeptide ubiquicidine with a molecular mass of 1.7 kDa has been developed. The radiochemical purity of the resultant labeled compound was more than 98%. A combination of ubiquicidine and 99mtechnecium showed stability in blood plasma. The biological study indicated that the complex was renally excreted from blood flow rapidly (the half-life is 30 min). It accumulated in the experimental inflammatory focus of laboratory animals, peaking 1-2 hours after intravenous injection when the inflammatory focus/intact tissue ratio amounted up to 2.6-3.4, which could yield satisfactory abscess scintigrams. The findings make it possible to consider ubiquicidine as a promising compound for the design of radiopharmaceutical to image inflammatory foci.

[Cardiac sympathetic innervation in patients with ventricular arrhythmias: an assessment by 123I-metaiodobenzylguanidine scintigraphy]

The aim of this study was to determine the state of sympathetic innervation in patients with ventricular arrhythmias (VA) using 123I-metaiodobenzylguanidine 123I -MIBG) scintigraphy. Fifty six patients (26 men and 30 women, mean age 37.4+/-11,6) underwent single-photon emission computed tomography (SPECT) imaging and planner scintigraphy after injection of 123I-MIBG (activity 148 MBq). They form three groups. Thirty patients with idiopathic VA (IVA) were included in group I: 14 patients with ventricular extrasystoles (VE) and 16 - with ventricular tachycardias (VT). Group II was formed by 17 patients (with dilated cardiomyopathy, n=7 and chronic myocarditis, n=10), 6 of them had VE and 11 - VT. The control group III was formed by 9 healthy subjects with structurally normal heart without VA. We analyzed early (30 minutes) and delayed (4 hours) images after 123I-MIBG administration. The global sympathetic activity (SA) was assessed by heart/mediastinum ratio and washout rate. Regional SA was assessed by extent and severity of defect. In group I 25 of 30 patients (83.3%) had regional SA abnormalities significantly different from controls (p<0.001). At the same time global uptake of 123I-MIBG in this group was not affected. In group II regional SA abnormalities were revealed in all patients (100%) and global reduction of 123I-MIBG uptake - in 14 patients (82.4%). Regional and global SA abnormalities in group II were different from controls (p<0.0001) and patients with IVA (p<0.001). There was no difference in SA abnormalities between patients with VE and VT. Our results suggest that patients with different VA have abnormalities of sympathetic innervation, including patients with structurally normal heart.

[Body mass loss due to orlistat therapy and multiple factors of cardiovascular risk]

AIM

To study effects of body mass loss due to orlistat on carbohydrate and lipid metabolism, insulin resistance, 24-h profile of arterial pressure (AP), left ventricular myocardial hypertrophy, brain perfusion in patients with metabolic syndrome (MS).

MATERIAL AND METHODS

Thirty middle-aged patients with MS entered the trial. They received orlistat in a dose 120 mg twice a day for 24 weeks. Before and after the treatment the patients' carbohydrate and lipid metabolism, insulin resistance were studied, 24-h monitoring of arterial pressure, echo-cardiography were made. Brain perfusion was studied with single-photon emission computed tomography in 18 patients. Results. All the patients lost much weight. This was accompanied with improved indices of AP profile, metabolism of carbohydrates and lipids, insulin resistance, left ventricular hypertrophy, brain perfusion. Conclusion. Orlistat treatment weakens basic factors of cardiovascular risk.

[Primary prophylaxis of cerebrovascular complications in patients with metabolic syndrome]

AIM

To study effects of antihypertensive therapy with bisoprolol and actovegin on cerebral perfusion in patients with metabolic syndrome.

MATERIAL AND METHODS

Thirty patients (18 women and 12 men) with metabolic syndrome and mild arterial hypertension took bisoprolol alone in a dose 5-10 mg/day, and fifteen patients received combined therapy (bisoprolol and actovegin) for 12 weeks. Before the study and 12 weeks later measurements were made of carbohydrate and lipid metabolism, single photon emission computed tomography investigated brain perfusion.

RESULTS

Improvement of brain perfusion was observed after both monotherapy with bisoprolol and its combination with actovegin.

CONCLUSION

Monotherapy with bisoprolol and bisoprolol combination with actovegin improved brain perfusion but the combination was more effective.

[Cerebral perfusion in patients with metabolic syndrome]

Cerebral perfusion was studied in patients with arterial hypertension combined with metabolic syndrome and diabetes mellitus type II. The data is compared to the results obtained for patients with a single disorder--metabolic syndrome, diabetes mellitus type II and arterial hypertension without metabolic alterations. It is shown that patients with disregulation of carbohydrate and lipid metabolism are more vulnerable to cerebral blood supply alterations. A level of perfusion was the same in patients with metabolic syndrome and diabetes mellitus type II. Besides, an acetazolamide application revealed that patients with metabolic syndrome had reduced cerebral vascular autoregulation.

[Impairment of cardiac sympathetic function in patients with acute myocardial infarction and unstable angina]

AIM

To assess the state of sympathetic innervation of the heart in patients with acute coronary syndrome.

MATERIAL

Patients with Q-myocardial infarction (MI, n=36), non-Q-MI (n=13), and unstable angina (UA, n=9).

METHODS

Each subject underwent single-photon emission computed tomography (SPECT) and planar scintigraphy using iodine-123 metaiodobenzylguanidine ((123)I-MIBG) for assessment of cardiac sympathetic function. We analyzed early (15 minutes) and delayed (4 hours) images after (123)I-MIBG administration. Resting (99m)Tc-MIBI myocardial scintigraphy was performed for evaluation of myocardial perfusion. Location, extent (%) and severity (Un.) of defects were determined using <<CEqual 3.0>> program. (123)I-MIBG did not accumulate in myocardium of 3.5% patients. All other patients demonstrated (123)I-MIBG accumulation defects. These defects were colocolized with (99m)Tc-MIBI uptake abnormalities. However both extent and severity of sympathetic innervation defects exceeded those of perfusion defects in all patients. Mean extent and severity of sympathetic neuronal damage areas were the greatest in patients with Q-MI (41+/-8% and 1119+/-377 Un. respectively) and the least in patients with UA (22+/-12% and 602+/-353 Un., respectively). On the contrary the mean extent of areas with sympathetic endings dysfunction but normal perfusion was the largest in UA group and the least in Q-MI group (18+/-11 and 10+/-7%, respectively, p<0,05).

CONCLUSION

Impairment of cardiac sympathetic function in patients with acute coronary syndrome could be detected by SPECT with (123)I-MIBG. Locations of (123)I-MIBG and (99m)Tc-MIBI defects were similar but sympathetic dysfunction areas were larger than areas with reduced perfusion. This result suggests higher sensitivity of sympathetic endings to ischemia compared with cardiomyocytes. Myocardial areas with sympathetic endings dysfunction but normal perfusion can be defined as myocardium at risk.

[Cerebrovascular complications in metabolic syndrome: possible approaches to decrease risk]

AIM

To compare brain perfusion in hypertensive patients with diabetes mellitus type 2 (DM2) or metabolic (MS) syndrome and hypertensive patients without clinicobiochemical signs of DM2 or MS; to study enoxaparin effects on brain perfusion in DM2 and arterial hypertension (AH).

MATERIAL AND METHODS

Seventy patients included in the study were divided into three groups: 30 patients with DM2 and AH (group 1), 30 patients with MS and AH (group 2) and 10 AH patients without manifestations of MS or DM2 (group 3). All the patients have undergone single-photon emission computed tomography (SPECT) of the brain, carbohydrate and lipid metabolism were examined.

RESULTS

Deterioration of brain perfusion was more prominent in DM2 and MS patients with AH than in hypertensive patients with normal metabolism. Stress test with acetasolamide revealed defective autoregulation of cerebral blood flow in hypertensive patients with DM2. A 6-week therapy with enoxaparin significantly improved brain perfusion in hypertensive patients with DM2.

CONCLUSION

Enoxaparin treatment of hypertensive DM2 and MS patients with abnormal perfusion of the brain can be used for prevention of cerebrovascular complications.

[Comparative effectiveness of different methods of diagnosis and correction of impaired portal circulation]

The diagnostic effectiveness of X-ray radionuclide and ultrasound determination of portal blood flow and the impact of different treatments on the blood flow were evaluated in 76 patients with hepatic cirrhosis. The treatment regimens were used propranolol (Group 1), isosorbide-5-mononitrate (monosan) (Group 2), and a combined therapy with propranolol in combination with diuretics and a course of intravenous laser irradiation (Group 3). In terms of both clinical and laboratory parameters and the status of portal circulation, the highest effect was observed in the patients receiving the combined therapy.

[Atenolol induced bradycardia in patients with stable angina: effects on exercise tolerance, myocardial perfusion and left ventricular contractility]

AIM

To assess effects of atenolol-induced heart rate decrease on myocardial perfusion, left ventricular contractility and tolerance to exercise in patients with chronic coronary artery disease.

MATERIAL AND METHODS

Twenty eight men (mean age 54,5-/+9,2 years) with stable class I-III angina and positive reproducible result of bicycle exercise test underwent rest/stress 99mTc-MIIBI gated single-photon emission computed tomography (SPECT) before and after 10 days of administration of atenolol (20 patients) or placebo (8 patients). Dose of atenolol was titrated to achieve at least 15% decrease of heart rate from baseline.

RESULTS

After 10 days of treatment with atenolol heart rate decreased from 78-/+3.1 to 59-/+1.1 bpm (p=0.01), whereas in placebo group there were no significant changes. Compared with placebo, treatment with atenolol was associated with significant decreases in extent and severity of perfusion defects, ischemic score and number of ischemic segments. No significant changes of parameters of left ventricular contractility occurred. Treatment with atenolol was associated with symptomatic improvement and increase of the total exercise time.

CONCLUSION

Heart rate lowering during monotherapy with atenolol was associated with improvement of myocardial perfusion and tolerance to exercise.

[Effect of restoration of coronary blood flow on dynamics of myocardial perfusion and function in patients with acute myocardial infarction. Data of gated technetium-99m-sestamibi SPECT]

Effects of coronary blood flow restoration on dynamics of myocardial perfusion and function were studied in 50 patients with acute myocardial infarction during 6-month follow-up. Gated SPECT with 99mTc-MIBI (G-SPECT) was performed before onset of reperfusion procedures, in 24 hours, 10 days, 1 and 6 months. In patients with successful reperfusion (n=36) perfusion defect (PD) size decreased by 6.78+/-0.97% (p<0.001) and its severity by 221.3+/-85 std (p<0.001) in 24 hours. In 10 days PD size decreased by 3.9+/-0.88% (r<0.05) and severity by 149+/-39 std (p<0.05), whereas in 1 month PD size decreased by 2,18+/-1,4% (p<0.05), PD severity by 146.3+/-67 std (p<0.05). Successful reperfusion was associated with improvement of contractility: left ventricular ejection fraction increased by 3% (p<0.05) on day 10 of the disease. In patients with failed reperfusion PD size and severity decreased in 10 days by 4.8+/-4.2%, p<0.05, and 276+/-75 std, p<0.05, respectively, in 6 months PD size decreased by 3.1+/-0.9%, p<0.05, left ventricular ejection fraction did not change during follow-up. We conclude that successful reperfusion therapy promotes restoration of myocardial perfusion and improvement of its contractility.

[Evaluation of myocardial perfusion in patients with hypertrophic cardiomyopathy in comparison with clinical and echocardiographic data]

AIM

To study peculiarities of myocardial perfusion in patients with hypertrophic cardiomyopathy (HCMP) in correlation with clinical and echocardiographic data.

MATERIAL AND METHODS

62 patients with HCMP (23 females and 39 males, mean age 44.4 +/- 11.2 years, the disease duration 13.0 +/- 10.4 years) have undergone ECG, 24-h ECG monitoring, echocardiography, perfusion scintigraphy of the myocardium with 99m-TcMIBI at rest and in combination with bicycle ergometry. The patients were divided into two groups: 35 patients of group 1 had moderate left ventricular hypertrophy (the septal thickness in diastole under 20 mm; 27 patients of group 2 had severe hypertrophy (the thickness was over 20 mm).

RESULTS

Dyspnea and syncopal states occurred more frequently in patients from group 2. They also had a higher functional class of heart failure (2.0 +/- 0.8 and 1.2 +/- 0.7 for group 1 and 2, respectively, p < 0.05). Cardiac performance was significantly higher in patients of group 1. The size of the left atrium, left ventricular myocardium mass, the septal thickness and thickness of posterior wall of the left ventricle, gradient of pressure in the outflow tract of the left ventricle proved higher in patients of group 2. Deep stable defects of myocardial perfusion were detected in 5 (15%) patients of group 1 and 10 (37%) patients of group 2. Transient defects of myocardial perfusion were found in 9 (26%) patients of group 1 and 12 (44%) patients of group 2. The index of myocardial ischemia in group 1 patients was significantly lower than in patients of group 2 (3.5 +/- 2.2 and 8.3 +/- 2.5, respectively, p < 0.05).

CONCLUSION

Patients with severe hypertrophy of the left ventricle had severe clinical picture, low exercise tolerance, marked hemodynamic changes, more frequent defects of left ventricular perfusion defects compared to patients with moderate hypertrophy of the left ventricular myocardium.

[Preliminary data on combined assessment of tolerance to exercise, left ventricular contractile function in ischemic heart disease patients taking bradycardic agents]

AIM

To study effects of bradicardia induced by atenolol, diltiazem and ivabradin on exercise tolerance, myocardial perfusion and left ventricular contractile function in patients with stable angina pectoris.

MATERIAL AND METHODS

The trial included 7 male patients aged 57 +/- 2.6 years with coronary heart disease, stable angina of functional class II free of cardiac failure and severe arterial hypertension, with a positive and reproducible VEM test after therapy discontinuation. For 10 consecutive days with 5-day intervals, all the patients received atenolol, diltiazem, ivabradin in doses lowering heart rate at rest by 20% from the initial level. Before the treatment all the patients were studied with VEM test, perfusion synchronized single-photon emission computerized tomoscintigraphy of the myocardium (PSSPECT) at rest and exercise. On day 10 of each drug intake PSSPECT and VEM test were performed if the expected heart rate was achieved.

RESULTS

Each of the studied drugs resulted in a 22-24% reduction in the heart rate at rest accompanied by a significant rise in exercise tolerance, improvement of performance and myocardial perfusion. There were no significant changes in left ventricular contractility.

CONCLUSION

A 20% reduction in resting heart rate due to monotherapy with drugs having a bradicardic effect leads to positive changes in exercise tolerance and myocardial perfusion.

[Comparative assessment of resting myocardial perfusion in patients with postinfarct cardiosclerosis by electron-beam tomography and 99mTc-MIBI myocardial single-photon tomography]

The purpose of the study was to compare myocardial perfusion assessed by electron beam computed tomography (EBCT) with that obtained by 99mTc-sestamibi single photon emission computed tomography (SPECT) in patients with old myocardial infarction and control subjects at rest. A total of 42 patients with suspected and known ischaemic heart disease (IHD) were included in the study. 20 pts had a history of Q-wave myocardial infarction (MI), 12 pts had an old non-Q-wave MI and 10 served as controls (without perfusion defects on SPECT images at rest). Assessment of the myocardial perfusion by EBCT was performed using the short axis view and multislice mode (MSM) during injection of 50 ml of the nonionic contrast medium at 4 ml/s via cubital vein. Perfusion defects were localized by SPECT according to 6-segment model of the LV (septal, anterior, lateral, posterior, inferior and apical). Overall concordance between EBCT and SPECT was 67% for normal versus abnormal perfusion. Agreement between the 2 methods for each of the 6 segments was 81% (K = 0.62) for the anterior segment, 71% (K = 0.42) for the septal segment, 71% (K = 0.43) for the apical, 69% (K = 0.3) for the lateral segment, 48% (K = 0.13) for the posterior segment and 60% (K = -0.13) for the inferior segment. Discrepancies between the two of techniques were most notable in the posterior region. Beam hardening during passage of the contrast medium through the heart chambers and descending aorta is possible explanation of the artifacts on EBCT images. This study demonstrates that nowadays EBCT is not yet alternative to SPECT in the assessment of the myocardial perfusion in patients and further improvements of scanning techniques are necessary.