Respiratory Function of Mitochondria in Patients with Coronary Heart Disease with Implantable Cardioverter-Defibrillator.

We studied the respiratory activity of mitochondria in peripheral blood leukocytes from 36 patients with coronary heart disease (CHD) and a history of ventricular tachyarrhythmias required cardioverter-defibrillator implantation. The measurements were carried out in incubation buffers with different oxidation substrates (succinate and pyruvate-malate mixture). In pyruvate-malate incubation buffer, oxygen consumption rate and respiratory control coefficients in patients with triggered device did not differ significantly from those in patients without cardioverter-defibrillator triggering. At the same time, respiratory control coefficients were below the reference values. In succinate buffer, values of mitochondrial parameters were significantly lower in patients with triggered devices. Our findings indicate that mitochondria of patients with non-triggered cardioverters-defibrillators have better functional and metabolic plasticity. It was concluded that activity of respiratory processes in mitochondria could be an indicator that should be taken into the account when assessing the risk of developing ventricular tachyarrhythmias.

Radiomic Phenotype of Periatrial Adipose Tissue in the Prognosis of Late Postablation Recurrence of Idiopathic Atrial Fibrillation.

The aim of the study is to find new predictors of postablation atrial fibrillation (AF) recurrence in patients with lone AF using a texture analysis of the periatrial adipose tissue (PAAT) of the left atrium. Materials and Methods: Forty-three patients admitted for lone AF catheter ablation, who had undergone multispiral coronary angiography, were enrolled in the study. PAAT segmentation was performed using 3D Slicer application followed by extraction of 93 radiomic features. At the end of the follow-up period, patients were divided into 2 groups depending on the presence or absence of AF recurrence. Results: 12 months of follow-up after catheter ablation, postablation AF recurrence was reported in 19 out of 43 patients. Of 93 extracted radiomic features of PAAT, statistically significant differences were observed for 3 features of the Gray Level Size Zone matrix. At the same time, only one radiomic feature of PAAT, Size Zone Non Uniformity Normalized, was an independent predictor of postablative recurrence of AF after catheter ablation and 12 months of follow-up (McFadden's R2=0.451, OR - 0.506, 95% CI: 0.331‒0.776, p<0.001). Conclusion: The radiomic analysis of periatrial adipose tissue may be considered as a promising non-invasive method for predicting adverse outcomes of the catheter treatment, which opens the possibilities for planning and correction of patient management tactics after intervention.

Interstitial Edema of the Interatrial Septum in Patients with Atrial Fibrillation and Chronic Heart Failure.

We studied the presence of interstitial edema of the interatrial septum in patients with chronic heart failure (CHF) with atrial fibrillation (n=23) or without rhythm disturbances (n=9). The intensity of the MRI signal of the interatrial septum, interventricular septum, and skeletal muscle by T2-weighted MRI and the enhancement index of interatrial septum (the ratio of the signal intensity of the interatrial septum to the signal intensity of the skeletal muscle) were evaluated. The enhancement index of interatrial septum ⩾2 was regarded as an MRI sign of myocardial edema. The enhancement index of interatrial septum in patients with persistent atrial fibrillation was 2.4 (2.21; 2.69) and was higher than in CHF patients with paroxysmal atrial fibrillation and in CHF patients without arrhythmias and surpassed the control values (p<0.05), which indicates the presence of MRI signs of edema of the myocardium of the interatrial septum. The obtained data confirm the presence of myocardial edema of the interatrial septum in CHF patients and persistent form of atrial fibrillation, which expands the understanding of the pathogenesis of this condition.

Efficacy and Safety of Anticoagulant Therapy in Patients With Various Forms of Atrial Fibrillation After Interventional Treatment. Results of a Three-Year Follow-up.

Aim      To evaluate efficacy and safety of the anticoagulant therapy in patients with atrial fibrillation (AF) during a 36-month follow-up after an interventional treatment.Material and methods  This study included 302 patients aged 29 to 81 years with various forms of AF. Catheter ablation (CA) of AF foci was performed for all patients. The patients were divided into 3 groups: group 1 with paroxysmal AF, group 2 with persistent AF, and group 3 with longstanding persistent AF. Two subgroups were isolated in each group, with effective and ineffective CA. Results of the follow-up were analyzed at 12, 24, and 36 months after discharge from the hospital. The follow-up interview recorded complaints of palpitation attacks, effectiveness of administered CA, compliance with the treatment, adverse clinical outcomes, including thromboembolic complications (TEC), bleeding, and hospitalizations.Results Efficacy of the interventional treatment for 36 months was 65.3 % in patients with paroxysmal AF, 59.7 % in patients with persistent AF, and 57.1 % in patients with longstanding persistent AF. Patients with paroxysmal AF and effective CA had no adverse events throughout the same period during the antithrombotic treatment (ATT). In contrast, the group with ineffective ablation had both TEC and hemorrhagic complications during the ATT. In the group with persistent AF and effective CA throughout the follow-up period, TECs were less frequent than in the group of ineffective ablations during the ATT treatment. Patients with longstanding persistent AF and effective CA throughout the follow-up period, had no TECs in contrast to patients with ineffective ablation during the ATT treatment. There were no fatal outcomes in patients with effective procedure.Conclusion      A successful CA procedure for AF provides a significant decrease in the risk of ischemic stroke. Furthermore, the invasive strategy does not increase the risk of major and minor bleedings.

Cardiac 123I-mIBG scintigraphy for prediction of catheter ablation outcome in patients with atrial fibrillation.

BACKGROUND: Previous studies show inconsistent results on the role of innervation imaging (with 123I-mIBG) in predicting late atrial fibrillation (AF) recurrence after catheter ablation (CA). These studies included patients with paroxysmal AF and studied prognostic value of post-CA I-123-mIBG parameters. Current study investigated the ability of pre CA 123-I-mIBG imaging to predict late AF recurrence in patients with persistent AF. METHODS: 123I-mIBG cardiac imaging was performed before CA in 82 patients with persistent AF. Patient was followed for 12 months. RESULTS: Multivariable analysis demonstrated that late heart-to-mediastinum ratio (H/Mlate) and washout rate (WR) were independent predictors of AF recurrence. ROC-curve analysis data showed that H/Mlate <1.6 (sensitivity 73.53%, specificity 81.3%, AUC 0.792, P < .001) and WR > 25.11 (sensitivity 70.6%, specificity 70.8.3%, AUC 0.712, P < .001) indicate high probability of AF relapses during 12 months after CA. CONCLUSION: Pre-CA parameters of global cardiac sympathetic activity estimated by 123I-mIBG scintigraphy are associated with late AF relapses in persistent AF patients with normal LVEF and absence of significant CAD.

Research of spontaneous and stimulated functional activity of platelets in patients with different types of atrial fibrillation.

Platelet function testing is widely used to diagnose disorders of the cellular link of hemostasis. The study of platelet aggregation activity is relevant for the prevention of thromboembolic complications in atrial fibrillation and monitoring the effectiveness and safety of therapy. In this study, a comparative analysis of spontaneous and stimulated platelet aggregation in groups of patients with two types of atrial fibrillation was performed - paroxysmal and persistent. The effect of ß-adrenoblocker therapy on platelet aggregation activity in patients with atrial fibrillation was also studied. Platelet aggregation activity was studied using the method of G. Born in the modification of Z.A. Gabbasov on a two-channel laser analyzer "Biola". Collagen at a concentration of 2 mg / ml and adrenaline in a concentration range of 2.5-10 µg / ml were used as aggregation-promoting agents. It has been established that spontaneous aggregation potential and collagen-induced platelet aggregation depend on the type of atrial fibrillation, as well as on the presence or absence of ß-blockers in therapy. The response of platelets to stimulation with adrenaline depends, first of all, on the type of atrial fibrillation and the concentration of adrenaline in the reaction medium. The most significant changes were noted in the group of patients with a paroxysmal form atrial fibrillation, taking ß-blockers in therapy.

[Catheter treat-ment of patients with atrial fibrillation and myocardial inflammation].

The review presents current data on atrial fibrillation, therapeutic approaches, and possibilities of interventional treatment and addresses inflammatory heart damage and its interrelation with arrhythmia.The review presents current data on atrial fibrillation, therapeutic approaches, and possibilities of interventional treatment and addresses inflammatory heart damage and its interrelation with arrhythmia.

Myocardial Expression of SERCA2a and Structural and Functional Indices in Patients with Atrial Fibrillation.

The study examined the relationships between SERCA2a expression in the myocardium and structural and functional indices in patients with atrial fibrillation. In uniform cohort of patients, this expression differed significantly but positively correlated with the size of the left atrium, end-systolic volume, and end-diastolic volume. In contrast, SERCA2a expression negatively correlated with early (peak E) and late (peak A) diastolic filling rates in left ventricle. SERCA2a expression was also associated with echocardiographic parameters reflecting structural and functional status of the heart in patients with persistent atrial fibrillation.

[A change in adrenal responsiveness in sotalol-treated patients with paroxysmal atrial fibrillation depending on autonomic nervous system tone].

AIM: To evaluate the efficacy of sotalol depending on the magnitude of changes in adrenal responsiveness and autonomic nervous system tone in patients with paroxysmal atrial fibrillation (AF). SUBJECTS AND METHODS: Twenty-six patients with paroxysmal AF in the presence of coronary heart disease (CHD) and hypertension were examined. Sinus rhythm variability and sympathicotonic and vagotonic disorders were studied in patients with paroxysmal AF before and during sotalol treatment. A commercial Beta-ARM-Agat kit was used to estimate the adrenal responsiveness of erythrocyte membranes (ß-APM), which can judge the body's individual sensitivity to ß-adrenoblockers. RESULTS: Sotalol used in the average therapeutic doses of 160-240 mg did not reduce ejection fraction or increase atrioventricular conduction up to abnormal values. In patients with borderline and mild hypertension, the drug lowered blood pressure statistically significantly (p=0.01) and was well tolerated. The drug increased the sensitivity of ß-adrenoblockers in patients with adrenergic AF. CONCLUSION: The effect of sotalol on the autonomic nervous system manifested in the higher power of a high-frequency spectral component of heart rate variability than in that of a low-frequency one. Long-term sotalol administration significantly reduced ß-APM, increasing the sensitivity of adrenoceptors.

Coupling of the Functional Stability of Rat Myocardium and Activity of Lipid Peroxidation in Combined Development of Postinfarction Remodeling and Diabetes Mellitus.

Coupling of the functional stability of rat myocardium and activity of lipid peroxidation processes in combined development of postinfarction remodeling and diabetes mellitus has been studied. The functional stability of myocardium was studied by means of the analysis of inotropic reaction on extrasystolic stimulus, the degree of left ventricular hypertrophy, and the size of scar zone. It was shown that in combined development of postinfarction cardiac remodeling of heart (PICR) with diabetes mellitus (DM) animal body weight decreased in less degree than in diabetic rats. Animals with combined pathology had no heart hypertrophy. The amplitude of extrasystolic contractions in rats with PICR combined with DM had no differences compared to the control group. In myocardium of rats with PICR combined with DM postextrasystolic potentiation was observed in contrast with the rats with PICR alone. The rats with combined pathology had the decreased value of TBA-active products. Thus, the results of study showed that induction of DM on the stage of the development of postinfarction remodeling increases adaptive ability of myocardium. It is manifested in inhibition of increase of LPO processes activity and maintaining of force-interval reactions of myocardium connected with calcium transport systems of sarcoplasmic reticulum of cardiomyocytes.

[Interrelation of Electrophysiological and Perfusion Changes in Patients With Left Ventricular Aneurysm].

The study was aimed at identification of relations between perfusion and electrophysiological changes in left ventricular (LV) myocardium in patients with ischemic heart disease (IHD) with postinfarction LV aneurysm and ventricular tachycardia. The study enrolled 23 patients with the aforementioned disease. Preoperatively, apart from standard clinical examination of cardiosurgical patients, intracardiac electrophysiological study and perfusion single-photon emission computed tomography of myocardium with 99mTc-Technetril were performed. The patients were subjected to coronary artery bypass grafting and left ventricular reconstruction. Assessment of the outcomes showed that electrophysiological condition of left ventricle was dependent on myocardial perfusion. Electrophysologically normal myocardium with electric potential >1.5 mV, transient zone (0.5-1.5 mV) and zones with the potential <0.5 mV differed significantly by the percentage of perfusion: 61, 45, and 35%, respectively. Zones of delayed conduction and those of double potential were located mostly in transient zone of electrical potential conduction with the current amplitude of 0.5-1.5 mV and myocardial perfusion from 35 to 61%. Double potential zone was formed in the area of myocardium with better perfusion (perfusion defect of 55% with preserved metabolism) as opposed to the zone of delayed conduction, where perfusion defect was 40% with low level of metabolic activity. The obtained data has proven the presence of correlation between electrophysiology and perfusion of myocardium. This provides an opportunity to identify electrically unstable myocardial zones with the help of specific computer tomography of myocardium.

[Determination of the efficiency of single-photon emission computed tomography with 99mTc-HMPAO-labelled leukocytes in the diagnosis of myocarditis: Comparison of scintigraphic and histological data].

OBJECTIVE: to determine the efficiency of single-photon emission computed tomography (SPECT) with 99mTc-HMPAO- labelled leukocytes in diagnosing myocarditis, by comparing scintigraphic and histological data. MATERIAL AND METHODS: The investigation enrolled 35 patients with suspected myocarditis, who were planned to undergo coronaroventriculography or intervention with endomyocardial biopsy. Prior to endomyocardial biopsy, all the patients underwent myocardial scintigraphy using 99mTC-exametazime-labelled leukocytes. The results of myocardial scintigraphic and histological examinations were compared. RESULTS: Abnormal myocardial 99mTc-HMPAO-labelled leukocyte accumulation was detected in 7 (20%) examinees. Myocarditis was histologically verified in 9 (25.7%) persons. Our findings showed that the sensitivity of 99mTc-HMPAO-labelled leukocyte SPECT in diagnosing myocardial inflammatory changes was 62%; its specificity and diagnostic accuracy were 92% and 85%, respectively. Conclusion. 99mTc- HMPAO-labelled leukocyte scintigraphy is today one of a few procedures for the primary noninvasive diagnosis of myocardial inflammation. However, in view of its sufficiently low sensitivity and laboriousness and the sigh cost of consumables, the technique is irrationally used in routine clinical practice.

[Capabilities of 99mTc-pyrphotech single-photon emission computed tomography in combination with myocardial perfusion scintigraphy in the evaluation of inflammatory changes in the heart of patients with persistent atrial fibrillation].

AIM: To estimate the capabilities of 99mTc-pyrphotech single-photon emission computed tomography (SPECT) in the diagnosis of myocardial inflammatory changes in patients with persistent atrial fibrillation (AF). SUBJECTS AND METHODS: Nineteen patients (11 males and 8 females, mean age 47.46 ± 9.92 years) with persistent idiopathic AF underwent preoperative complete clinical and instrumental examination. 99mTc-pyrphotech SPECT was performed to identify foci of myocardial inflammatory changes. After completing 99mTC-pyrphotech scanning, resting myocardial perfusion scintigraphy with 99mTC-methoxyisobutylisonitrile (99mTc-MIBI) was performed in accordance with the standard protocol. The scintigrams obtained in both studies were then combined using the applied programs Jet Stream Workspace Release 2.5 (Philips) and the application Fusion. During invasive intervention, endomyocardial samples were intraoperatively taken from all the patients for histological and immunohistochemical examinations. RESULTS: Abnormal 99mTc-pyrphotech myocardial accumulation was found in 7 (36.8%) of the examinees, multiple foci in 3 cases and single foci in 4. Analysis of perfusion scintigrams indicated that the mean abnormal accumulation of 99mTc-MIBI in the left ventricle was 3.75 ± 0.88% (maximum 9%). Histological examination of endomyocardial samples from 19 patients with persistent AF verified myocarditis in 4 (21%) patients and myocardial sclerosis concurrent with other abnormalities in 15 (78.9%) patients. CONCLUSION: Latent lymphocytic or polymorphic cellular myocarditis of viral etiology is a cause of idiopathic AF in 20% of the cases. 99mTc-pyrphotech scintigraphy may be one of the primary noninvasive diagnostic techniques for the detection of myocardial inflammation in this form of arrhythmia.

[Manifestations of polymorphism of ß1-adrenoreceptors in patients with newly diagnosed cardiac rhythm disorders].

Individual peculiarities of the receptor apparatus of cardiomyocytes may determine pathological features of heart activity and susceptibility to pharmaceuticals. The possible role of beta-adrenoreceptor polymorphism in the development of cardiac rhythm disturbances is assessed by PCR. Special attention is given to A145G polymorphism of the ADRB1 gene in 127 patients with primary cardiac rhythm disorders. It was shown that AJ45G polymorphism (Ser49Gly) at DNA sites encoding for the amino acid sequence of beta-1 adrenoreceptors can influence the development of sex-specific cardiac rhythm disorders.