Epicardial Application of Hydrogel with Amiodarone for Prevention of Postoperative Atrial Fibrillation in Patients After Coronary Artery Bypass Grafting.

The objective of this study was to assess the safety and efficacy of local epicardial application of amiodarone-releasing hydrogel for prevention of postoperative atrial fibrillation (POAF) in patients after coronary artery bypass grafting. Patients were randomized into two groups: with the application of amiodarone-releasing hydrogel and the control group. It included 60 patients (47 males, 13 females) (mean age of 62 ± 8.5). POAF incidence differences were statistically significant between two groups: in the study group, the POAF incidence was 3.3%, while in the control group, the POAF incidence was 37% (p < 0.001). Statistically significant differences were revealed in the PQ interval duration. The risk of POAF incidence was calculated using the Cox regression model: the age and the application of amiodarone-releasing hydrogel application were statistically significant. Hospital length of stay in two groups was also different (р < 0.001). The age and the application of amiodarone-releasing hydrogel were statistically significant for POAF incidence.

Long-term results of isolated transmyocardial laser revascularization in combination with the intramyocardial autologous bone marrow stem cells injection.

To evaluate the long-term results of TMLR using a CO2 laser in combination with intramyocardial injection of ABMSC as an isolated procedure in patients with the end-stage coronary artery disease, the study included 20 patients (90% male), with a mean age of 58.4 ± 8.7 years. To assess the long-term results, patients were examined in a hospital. The Minnesota Living with Heart Failure Questionnaire (MLHFQ) and the Seattle Angina Questionnaire (SAQ) were used. The evolution of laboratory and instrumental indices, as well as medical therapy, was assessed. The end points of the study were death, acute myocardial infarction (AMI), repeated myocardial revascularization, recurrent hospitalizations due to coronary artery disease, and stroke. The changes in angina functional class were also evaluated. The median of follow-up period was 54 (36; 83) months, that is, 4.5 years. The analysis of the evolution of echocardiographic data showed the absence of statistically significant changes in the following parameters: left ventricular end-diastolic diameter (EDD) (p = 0.967), end-systolic diameter (ESD) (p = 0.204), end-diastolic volume (EDV) (p = 0.852), end-systolic volume (ESV) (p = 0.125), and left ventricular ejection fraction (LVEF) (p = 0.120). The patients continued to regularly take the main groups of medications. Nitrate consumption was significantly reduced (p < 0.001). Significant positive dynamics were observed in the changes in angina functional class. At the baseline, all patients had angina III FC, in the long term, 3 patients had II FC, 11 patients had I FC, and 6 patients had no angina. Clinical outcomes (mortality, recurrent myocardial infarction, stroke) were absent during the follow-up period. There were two cases of repeated myocardial revascularization. Regression analysis revealed that SYNTAX score was associated with the clinical outcome "repeated revascularization." TMLR in combination with intramyocardial injection of ABMSC is a safe method to achieve a statistically significant antianginal effect and reduce the need for "nitrates," which in turn improves the quality of life and reduces the frequency of hospitalizations due to coronary artery disease. These results can be achieved with strict adherence to the certain indications for the intervention.

Model of Human Cardiovascular System Containing a Loop for the Autonomic Control of Mean Arterial Pressure.

We proposed a model of human cardiovascular system that describes the cardiac cycle, the autonomic regulation of heart and vessels, the baroreflex, and the formation of arterial pressure. The model also makes allowance for the influence of respiration on these processes. It was found that an allowance for nonlinearity and insertion of a loop for the autonomic control of mean arterial pressure (having the form of self oscillating time-delay system) enables to obtain model signals with statistical and spectral characteristics that are qualitatively and quantitatively similar to.those for experimental signals. The model reproduces the phenomenon of synchronization of the loop for mean arterial pressure regulation with a basic frequency of approximately 10 s by the signal of respiration.

Statin therapy in the primary prevention of early atrial fibrillation after coronary artery bypass grafting.

OBJECTIVE: Assessment of the role of statin therapy in the prevention of postoperative atrial fibrillation (POAF) after coronary artery bypass grafting (CABG) in patients without prior atrial fibrillation. METHODS: A retrospective analysis of 206 patients, aged 57.2±7.9 years (mean±SD), who underwent isolated CABG is carried out. All patients are divided into two groups. The first group (nSt-patients) includes the patients who did not receive statin therapy prior to CABG (n=82). The second group (St-patients) includes the patients who received statin therapy prior to CABG (n=124). Both groups received the statin therapy from the first day after CABG. The risk of occurrence of POAF is evaluated using the Cox-regression model. RESULTS: The rate of POAF was 25.6% in nSt-patients and 6.5% in St-patients (P=0.020). On the 4th day after CABG, white blood cells (WBC) count was 11.0 (9.0, 13.0)×109/mL (medians with inter-quartile ranges) in nSt-patients and 9.0 (7.6, 10.2)×109/mL in St-patients (P<0.001). The peak WBC numbers occurred on the day of POAF onset. The Cox-regression analysis shows that only two factors (statin therapy and number of grafts) had significant influence on the POAF onset. Odds ratio of POAF event prediction by statin therapy was 0.20 (95%CI: 0.08-0.51), P<0.001. Each subsequent graft increased the risk of POAF in 2.1 times. CONCLUSION: Statin therapy carried out prior to the CABG is an effective approach to primary prevention of POAF in early postoperative period. Statin therapy after CABG in nSt-patients does not give prophylactic effect observed in St-patients.

Correlations Between Cardiovascular Autonomic Control Indices During the Two-hour Immobilization Test in Healthy Subjects.

OBJECTIVE: The aim of the present study was to assess the features of dynamics of cardiovascular autonomic indices and correlations between them during the two-hour immobilization test in healthy subjects. METHODS: Photoplethysmogram (PPG) and electrocardiogram were recorded simultaneously during the two-hour immobilization test in 14 healthy subjects (5 men and 9 women) aged 29±5 years (mean±SD). Dynamics of heart rate variability (HRV) power spectrum in high-frequency and low-frequency ranges (in ms2 and percents of total spectral power), mean heart rate (HR), and index S of synchronization between 0.1-Hz rhythms in PPG and HR were analyzed. RESULTS: Individual dynamics of all studied cardiovascular autonomic indices during the two-hour immobilization test was unique in each healthy subject. Two groups of healthy subjects were identified basing on individual features of autonomic control. The group with initial low level of index S maintained the low level of S during the two-hour immobilization test. The group with initial high index S maintained the high level of S only during the first 100 minutes of test. During the last 20 minutes of test, index S was similar in both groups. Many cardiovascular autonomic indices correlate between themselves for an individual subject, but they do not correlate between the subjects. Multiple regression analysis in each subject has shown a high correlation between mean HR and all other studied autonomic parameters in 57% of subjects (multiple R>0.9, P<0.05). For 204 records analyzed without taking into account the individual features of subjects, the above mentioned correlation was smaller (multiple R=0.45, P<0.001). Index S was found out to be the most independent one among the autonomic indices. CONCLUSION: Cardiovascular autonomic control is characterized by a pronounced variability among healthy subjects and stability in time in each subject. We have not found any regularity in variation of cardiovascular autonomic indices, which is common for the entire group of healthy subjects during the two-hour immobilization test. Mean HR is a summary index of efficiency of heart autonomic control. Index S is the most independent cardiovascular autonomic parameter.

A comprehensive assessment of cardiovascular autonomic control using photoplethysmograms recorded from the earlobe and fingers.

We compare the spectral indices of photoplethysmogram variability (PPGV) estimated using photoplethysmograms recorded from the earlobe and the middle fingers of the right and left hand and analyze their correlation with similar indices of heart rate variability (HRV) in 30 healthy subjects (26 men) aged 27 (25, 29) years (median with inter-quartile ranges) at rest and under the head-up tilt test. The following spectral indices of PPGV and HRV were compared: mean heart rate (HR), total spectral power (TP), high-frequency (HF) and low-frequency (LF) ranges of TP in percents (HF% and LF%), LF/HF ratio, and spectral coherence. We assess also the index S of synchronization between the LF oscillations in HRV and PPGV. The constancy of blood pressure (BP) and moderate increase of HR under the tilt test indicate the presence of fast processes of cardiovascular adaptation with the increase of the sympathetic activity in studied healthy subjects. The impact of respiration on the PPGV spectrum (accessed by HF%) is less than on the HRV spectrum. It is shown that the proportion of sympathetic vascular activity (accessed by LF%) is constant in the PPGV of three analyzed PPGs during the tilt test. The PPGV for the ear PPG was less vulnerable to breathing influence accessed by HF% (independently from body position) than for PPGs from fingers. We reveal the increase of index S under the tilt test indicating the activation of interaction between the heart and distal vessels. The PPGV spectra for finger PPGs from different hands are highly coherent, but differ substantially from the PPGV spectrum for the ear PPG. We conclude that joint analysis of frequency components of PPGV (for the earlobe and finger PPGs of both hands) and HRV and assessment of their synchronization provide additional information about cardiovascular autonomic control.

Non-invasive evaluation of the kinematic activity of the intact left ventricle of the heart.

Vector analysis of the movement of the epicardium has been used to calculate the energy efficiency of different parts of the left cardiac ventricle. The protocol based on the results of these calculations would allow the calculation of the potential power of myocardial contraction.

[Efficacy of Statin Therapy in the Prevention of Atrial Fibrillation in Early Postoperative Period after Coronary Artery Bypass Grafting].

BACKGROUND: The incidence of the postoperative atrialfibrillation (POAF) after open heart surgery is up to 65%. Statin therapy has shown conflicting data in the prevention of the POAF. OBJECTIVE: Our aim was eo evaluate the role of statin therapy in the primary prevention of AF after CABG. METHODS: Group 1 (n = 82) included those patients who received no statin therapy and the Group 2 (n = 124) included those patients who did receive statin therapy for at least three days prior to the operation and for all days in the postoperative period. WBC count in different periods after surgery and rate of AF were evaluated. The risk of occurrence of postoperative AF was evaluated using the Cox-regression model and odds ratio. RESULTS: A retrospective analysis of 206 medical records of the patients without pre-existing AF after CABG was performed. The rate of AF was 26% in Group 1 and 6.5 % in Group 2 (p = 0.0001). On Day 4 after surgery, WBC count was 11 (9;13) in the first group and 9 (7.6;10.2) x 10(9) e/L in the second group (p = 0.000001). "Statin use" and "number of grafts" and were found to be statistically meaningful: p = 0.002 and p = 0.0125 respectively (χ2 = 28.3; p < 0.001). In accordance with the Cox model of regression, the risk of AF was 0.201 for "statin use"; and 2.099 for "number of grafts". Odds ratio was 0.2 (95% CI 0.08-0.5). CONCLUSION: Statin therapy prior to and after GABG wasfound to be an effective method of primary prevention of AF in the early postoperative period.