Biomedical subjects
Publications and source records attributed to I S Iavelov.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Data of about 50 consecutive patients with acute coronary syndromes aged at least 18 years admitted to 59 hospitals in different Russian cities were collected from November 2000 to July 2001. In 1412 patients included into registry presumably ischemic symptoms within previous 24 hours were associated with ST-segment elevation or left bundle branch block on ECG. Demographics, history, characteristics of acute coronary syndrome, management and outcomes during hospitalization as well as diagnoses at presentation and discharge were analyzed. Markers of myocardial necrosis were measured in 61% of patients. Rates of interventions that may improve outcome appeared to be low. In acute phase aspirin was used in 79% (contraindications were reported in 6.2%). Within 12 hours of symptoms onset thrombolysis was performed in 12.9%, coronary angioplasty in 1.2%. In patients hospitalized within 12 hours of symptoms onset these rates were 21.3 and 1.9%, respectively. Beta-blockers were prescribed no more than in 60% of cases (fist dose intravenously in 4.3%). Lipid lowering drugs were recommended at discharge to 12.3% of patients (to 21.1% of those with known hypercholesterolemia). ACE inhibitors during hospitalization were used in 68.1% of patients. After acute phase of the disease coronary angioplasty was performed in 5 patients, CABG in 1. However hospital mortality appeared to be not high (8.5% in general, 10.1% in patients with overt acute myocardial infarction at presentation). Reinfaction rate in this registry was impossible to assess, angina recurrences were registered in every fifth patient.
BACKGROUND: Low heart rate variability (HRV) reflecting predominance of sympathetic tone is an independent predictor of sudden cardiac death after myocardial infarction (MI). We have previously shown that decreased heart rate (HR) response during reflex tests (breathing 6 per minute and Valsalva maneuver at the end of the first week after MI is also associated with elevated risk of sudden death during subsequent 2 years. AIM: To elucidate relationship between HR response to breathing 6 per minute and Valsalva maneuver, and HRV as standard non-invasive method of assessment of autonomic regulation of the heart. MATERIAL: Tests with breathing 6 per minute and Valsalva maneuver were performed on 4-11 (median 8) days of MI in 188 patients (68.1% males) aged 34-75 (median 62) years, 93.6% of whom received beta-blockers. Parameters studied were difference between maximal and minimal HR during 1(st) min of controlled breathing (DHR) and Valsalva ratio (VR). Standard time- and frequency-domain HRV measures were calculated from 15-min ECG strips at bed rest just before tests and from 24-hour ECG recordings after tests. RESULTS: In patients with low values of DHR (<3.36) and VR (<1,13) most of HRV parameters were also significantly decreased. Most close association was found between low DHR and low SDNNi and LF power calculated from 24-hour Holter recordings, between low VR and low LF power at bed rest. CONCLUSION: Direct correlation between HR response to reflex tests and parameters of HRV allows to suggest that decreased HR response to controlled breathing and Valsalva maneuver in patients with recent MI also reflects presence of marked sympathetic predominance.
UNLABELLED: Long term heart rate variability is used for prediction of sudden cardiac death (SD). There are simpler methods of assessment of autonomic cardiac control - registration of heart rate response to reflex tests and determination of heart rate variability (HRV) on short ECG recordins. Comparative value for prognosis of SD after myocardial infarction (MI) of these 3 techniques has not been studied yet. METHODS: Valsalva maneuver with calculation of Valsalva ratio (VR) and deep breath test with calculation of difference between average maximal and minimal HR during first minute of test (HR difference - HRD) were performed in 188 patients on days 4-11 of MI (68.1% men, age 34-75 years, 93.6% on beta-blockers, without heart failure NYHA IV on the day of tests). Time and frequency domain HRV measures were assessed during 15 min at bed rest and at Holter monitoring for median 24 h on the same day as reflex tests. RESULTS: During follow up for 2.1+/-0.8 years there were 9 sudden and 13 non-sudden cardiac deaths. ROC analysis was used to determine cut-off values of VR, HRD and HRV measures for dichotomization of patients into those with low- and high-risk of SD and these values were used in logistic regression analysis. The following parameters were univariate predictors of SD: obtained at reflex tests - VR <1.13 (OR 7.8, 95% CI 1.6-39.0; p=0.012), HRD <3.36 (OR 4.3, 95% CI 1.1-16.9; p=0.034); HRV parameters from 15 min ECG recordings - total frequency power <739 ms(2), VLF power <294 ms(2), LF power <197 ms(2) and LF/HF <1.5; HRV parameters from long term ECG recording - LF power <491 ms(2), LF/HF <1.4. At multivariate analysis only LF power for 15 min <197 ms(2) among HRV parameters remained independent predictor of SD (OR 24.2, 95% CI 2.4-245.5; p=0.007). Other predictors were clinical - VF during acute phase of MI (OR 94.7, 95% CI 4.2-2115.2; p=0.004) and history of MI (OR 8.4, 95% CI 1.4-48.5; p=0.017). CONCLUSION: In this population of patients without severe heart failure low LF power on 15 min resting ECG recordings on days 4-11 of MI was more powerful predictor of sudden cardiac death during subsequent 2 years than other HRV parameters including heart rate response to Valsalva maneuver and deep breath test.
BACKGROUND: Some evidence exists that heart rate response to simple provocative maneuvers may predict sudden cardiac death (SD) after myocardial infarction (MI). However optimal test has not been not established yet. Aim of this study was to compare prognostic value of different noninvasive reflex tests after MI. METHODS: Four reflex tests were consecutively performed in 188 patients on days 4-11 of MI (68% men, age 34-75 years, 93.6% on beta-blockers, without heart failure NYHA IV on the day of tests). Time- and frequency domain heart rate variability measures were obtained during 5 min at active standing and at bed rest with controlled breathing 6 and 15 per minute. In addition difference between average maximal and minimal heart rate at first minute of breathing 6 per minute (HRD) and Valsalva ratio (VR) were calculated. ROC analysis was used to determine cut-off values of studied measures for dichotomization of patients into those with low- and high-risk of SD and these values were used in logistic regression analysis. RESULTS: During follow up for 2.1+/-0.8 years there were 9 SD. Univariate predictors of SD were follows: HRD <3.36; VR <1.13; pNN 50 <2.5, total spectral power <1021 ms(2), LF power <229 ms(2) and HF power <65 ms(2) at active standing; pNN 50 <2.3, LF power <129 ms(2) and HF power <111 ms(2) during controlled breathing 15 per minute. HF power <65 ms(2) during active standing (OR 28.8, 95% CI 4.1-104.2; p=0.0001, positive predictive value 29.4%) and VR <1.13 (OR 6.0, 95% CI 1.02-34.3; p=0.04, positive predictive value 11.5%) were independent predictors of SD. For combination of these parameters OR increased to 34.9 (95% CI 6.7-181.6; p<0.001), positive predictive value to 50%. CONCLUSION: Among simple noninvasive reflex tests in this small group of patients with routine beta-blockers use and without severe heart failure active standing with calculation of HF power seems preferable method for prediction of SD after MI. Its predictive value may be enhanced by combination with Valsalva ratio.
UNLABELLED: Prognostic significance of heart rate (HR) response to easy to perform provocative maneuvers such as Valsalva maneuver and deep breath requires further elucidation. METHODS: Valsalva maneuver with calculation of Valsalva ratio (VR) and deep breath test with calculation of difference between average maximal and minimal HR during first minute of test (HRD) were performed in 210 patients on days 4-11 of myocardial infarction (MI). This analysis included data from 188 patients (68,1% men, age 34-75 years, 93.6% on beta-blockers during test). RESULTS: During period of follow up for 2.1+/-0.8 years there were 9 sudden (SD) and 13 non-sudden (non-SD) cardiac deaths. ROC-analysis allowed to determine optimal prognostic values of VR (<1.13) and HRD (<3.36) for SD. For non-SD these values could not be determined. According to univariate logistic regression analysis predictors of SD were as follows: VR<1.13 (OR 7.8, 95% CI 1.6-39.0, p=0.012), HRD <3.36 (OR 4.3, 95%CI 1.1-16.9, p=0.034), history of MI, ventricular fibrillation during first 24 h of MI, clinical heart failure (NYHA class II-III) on the day of tests. At multivariate analysis independent predictors of SD were history of MI (OR 8.3, 95% CI 1.5-46.2, p=0.015), ventricular fibrillation during first 24 h of MI (OR 72.3, 95% CI 5.1-1032.9, p=0.002) and VR <1.13 (OR 7.36, 95% CI 1.3-41.7, p=0.024). Univariate predictors of non-SD included history of MI, history of heart failure, HR on admission and postinfarction angina. HR on admission >/= 91 bpm was the single independent predictor of non-SD (OR 3.8, 95% CI 1.1-13.0, p=0.034). CONCLUSION: Valsalva ratio <1.13 on days 4-11 of MI in patients with sinus rhythm and without severe heart failure was associated with high risk of SD but not of non-SD during 2 years of follow up.
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BACKGROUND: Heart fatty-acid-binding protein (FABP) is supposed to be the most sensitive biomarker of myocardial necrosis in patients with Q-wave myocardial infarction (MI) and non-diagnostic ECG during first hours after onset of symptoms. However, diagnostic value of FABP in patients with non-ST elevation acute coronary syndrome (NSTEACS) is not well established. AIM: To elucidate diagnostic value of FABP in patients with NSTEACS hospitalized within time interval considered to be too early for a majority of biochemical tests. MATERIAL AND METHODS: FABP levels were measured by immunofluorometry (HyTest, Finland) in 44 patients (26 men, mean age 69+/-8.9 years) at admission within 6 hours (median - 2 h) from onset of index attack of angina and in 6, 12, 24 hours after onset of pain. Cut off FABP level was 12 ng/ml. Serum cardiac troponin I was measured for diagnosis of MI on admission and twice during first 24 hours of hospital stay. Cut off TnI level was 0.4 ng/ml. RESULTS: Acute MI was diagnosed by TnI above cut off in 31 patients (70.5%). There were no new-Q-wave MIs. Average ratio of observed serum FABP level to diagnostic cut off value on admission and in 6, 12, 24 hours after onset of pain was higher in patients with MI than in patients with unstable angina (1.01, 1.53, 0.81, 0.66 and 0.78, 0.51, 0.65, 0.56, respectively). The difference was maximally significant in 6 hours after onset of pain (p=0.018). Among patients with MI admission FABP compared with admission TnI more frequently exceeded diagnostic level (in 18 vs 9 patients, respectively, p=0.009). Sensitivity and specificity of admission levels of FABP and TnI for diagnosis of MI were 58 and 85%, 29% and 100%, respectively. CONCLUSION: In patients with NSTEACS during first 6 hours after pain onset FABP compared with TnI has greater sensitivity for detection of MI and sufficient specificity. FABP can be used as additional diagnostic tool for MI detection in early admitted patients with NSTEACS.
In order to assess practicability and safety of simple autonomic tests in survivors of acute phase of myocardial infarction (MI) attempts to carry out active orthostatic test, tests with controlled breathing (6 and 15 breaths per min), and Valsalva maneuver were performed in 210 patients on days 4-11 of MI. All patients had no signs of severe heart failure, were in sinus rhythm and did not interrupt standard therapy which included beta blockers. Tests were not completed in 14 patients (4.8%): orthostatic test in 6 due to hypotension, Valsalva maneuver in 3 because they did not reach required pressure in respiratory airways, and controlled breathing in 6 because of shortness of breath and substernal pain. All symptoms disappeared spontaneously and none of them was accompanied by ECG changes. All other tests were successfully completed without complications. Thus simple autonomic tests used in this study can be safely carried out in most stable patients on days 4-11 of MI.
Data from about 50 consecutive patients with acute coronary syndromes aged > or =18 years admitted to 59 hospitals in different Russian cities were collected between November 2000 and July 2001. In addition to presumably ischemic symptoms within previous 24 hours they were to have ischemic ECG changes, documented coronary heart disease or positive markers of myocardial necrosis. Of 2806 patients included into registry 1394 (49.7%) had non-ST elevation acute coronary syndrome. Markers of myocardial necrosis (mainly CK activity) were evaluated in 59.5% of them. Frequency of interventions known to improve outcome was rather low: aspirin in acute phase was used in 73% (contraindications were reported just in 6%), thyenopyridines - in few cases, unfractionated heparin intravenously only with APTT control - in 11.8%, low-molecular weight heparins - in 7.4% of patients. Beta-blockers were prescribed in 55.6% of cases (with fist dose intravenously in 2.9%). Lipid lowering drugs were recommended on discharge to 15% of patients (to 20% with known hypercholesterolemia). Coronary angiography and revascularization procedures were performed in 25 (1.8%) and 11 (0.8%) patients, respectively. However hospital mortality appeared to be relatively low (3.8%). Meanwhile rates of (re)infactions and angina recurrences during hospitalization were high - 16.5 and 25.1% of cases, respectively.
AIM: To compare diagnostic value of a novel marker of myocardial necrosis heart fatty acid binding protein (FABP) with that of troponin I (TnI) and total creatine kinase (CK) in patients admitted early after onset of ST-elevation acute coronary syndrome. MATERIAL: Fifty seven patients with ST-segment elevations justifying thrombolytic therapy admitted within 6 hours (29/57 within 3 and 12/57 - 2 hours) after onset of chest pain. In all patients myocardial infarction (MI) was eventually confirmed by development of Q waves and/or diagnostic increase of CK. METHODS: Samples of blood were taken at admission to coronary care unit. Cut-off values for an elevated level of FABP was 12 ng/ml, TnI - 1.2 and 0.4 ng/ml, CK - 400 IU/l. RESULTS: Overall FABP was elevated in 47 (83%), TnI - in 16 (28.1%), CK in 7 (12.3%) patients. Among patients admitted within first 3 and 2 hours FABP was elevated in 23/29 (79.3%) and 11/12 (91%), TnI - in 9/29 (31%) and 5/12 (41.7%), CK in 3/29 (10.3%) and 1/12 (8.3%) patients, respectively. The use of lower cut-off of abnormality (0.4 ng/ml) increased proportion of patients with elevated TnI up to 56.1% in the group as a whole, to 48.3% and 50% among patients admitted within first 3 and 2 hours, respectively. Nevertheless proportion of patients with elevated FABP remained higher with difference being significant for the whole group and patients admitted within first 3 hours (p=0.004 and 0.016, respectively). CONCLUSION: Most patients with ST-elevation acute coronary syndrome hospitalized within 2-6 hours after onset of pain had elevated levels of heart FABP.
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Aspirin and heparin are regarded as drugs that improve a prognosis in patients with unstable angina, but their comparative efficiency has not been elucidated yet. A randomized double-blind placebo-controlled study of oral aspirin (165 mm once daily) versus intravenous infusion of heparin (1,000 units per hour) was carried out in 94 patients with acute unstable angina (the mean interval after the last anginal attack 5.7 +/- 4.6 hours). During hospital stay, cardiac events (Q wave myocardial infarction or cardiac death) developed in 6 out of 46 patients on aspirin and 6 out of 48 patients on heparin. A significant superiority of heparin during its infusion (1 case of myocardial infarction versus 4 on aspirin) disappeared during the following 24 hours when 2 patients on heparin developed myocardial infarction (due to rebound phenomenon?). Two patients on heparin underwent coronary artery bypass surgery. Among complications only minor bleeding occurred. The results of this study demonstrated no significant benefits of intravenous heparin infusion over oral aspirin during hospitalization in patients with unstable angina. A high incidence (13%) of poor outcomes observed with the two drugs indicates that it is necessary to search for more beneficial antithrombic interventions.
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The paper deals with a device designed for the express-examination of the cardiac-vascular system through reading and processing the synchronously incoming electrocardiosignal and pulse-wave. The equipment is convenient for monitoring intraoperatively the functions of pacemaker due to its ability to select an optimal regimen not only for ECG but also for the pulse-wave. The new method of registering the pulse-wave by a miniature fiber-optic pressure sensor is described.
The outcomes of X-ray endovascular dilatation of coronary arteries in 46 patients with unstable angina pectoris are presented. Angioplasty proved to be angiographical-ly effective in 15 cases, anginal episodes ceased in 13. In 5 patients, successful dilatation was accompanied by coronary intimal dissection, as evidenced by angiography; however, its clinical effect was good. Low incidence rates of complications was likely to be associated with the relative normalization of the patients' condition during intensive drug therapy.