A new dosage form of lappaconitine hydrobromide has been created – the long-acting drug Allaforte®, which has fewer side effects compared to the traditional dosage form (Allapinin®). Objective. To evaluate the effectiveness, safety and tolerability of Allaforte® therapy in comparison with the drug Rytmonorm® in patients with paroxysmal atrial fibrillation (AF). Material and methods. Patients who met the inclusion criteria and those who did not meet the non-inclusion criteria were randomized into 2 groups: 1st (n=50) – patients received Allaforte® 25 mg 3 times a day with an increase in dose to 50 mg 2 times a day when detected attack of AF; 2nd (n=50) – patients received Rytmonorm® 150 mg 3 times a day with an increase in dose to 300 mg 2 times a day if an attack of AF was detected. Results. The average time from the first dose of the drug to the development of AF paroxysm in the 1st group (Allaforte®) was 98.877±6.022 days, in the 2nd group (Rytmonorm®) – 98.808±5.876 days, the average time from the first dose of the drug to the completion of the study – 105.740±5.032 and 103.732±5.353 days, respectively. The drugs Allaforte® and Rytmonorm® equally improved the quality of life of patients. A comparative analysis in groups according to the severity of adverse events and their cause-and-effect relationship with the drug did not show significant differences. Conclusion. The study drugs showed comparable effectiveness in preventing attacks of AF with similar safety and tolerability.

Aim. To develop diagnostic criteria for proximal left bundle branch block (LBBB) based on non-invasive methods and to determine the significance of these criteria in predicting the effect of cardiac resynchronization therapy (CRT).Material and methods. To develop criteria, 58 patients (21 men, mean age, 76,1±7,1 years) with LBBB occurred immediately after transcatheter aortic valve implantation (TAVI) were included. To assess the significance of the developed criteria, the second group included 22 patients (11 men, mean age, 57,9±9,3 years) with dilated cardiomyopathy (DCM), who had indications for CRT. The effectiveness of CRT was assessed by echocardiography 6 months after implantation. All patients in the DCM group and 15 patients in the TAVI group underwent superficial epiand endocardial non-invasive mapping using Amycard 01C EP Lab (EP Solutions SA, Switzerland). Patients in the DCM group underwent contrast-enhanced cardiac magnetic resonance imaging (MRI) before device implantation.Results. The criteria for proximal LBBB included 3 electrocardiographic features: QRS complex >130 ms in women and 140 ms in men, QSor rS-configuration in V1 lead, notch in two or more lateral leads (I, avL, V5, V6), and 2 mapping criteria: characteristic location of block line and delayed activation point. In the DCM group, the criteria were positive in 13 of 22 patients (59%). The developed criteria for proximal LBBB showed a relatively strong, significant relationship with the positive effect of CRT (сhi-square test =5,46, p=0,02, Cramer test =0,5, odds ratio (OR)=15,0, 95% confidence interval (CI), 1,32-169,9, p=0,002). An additional analysis showed that both the criteria for proximal block and CRT effect are associated with myocardial fibrosis according to MRI. In particular, intramural stria-shaped contrast accumulation in the interventricular septum leads to a change in characteristic of proximal block mapping phenomena — displacement of delayed activation point (chi-square test =13,9, p<0,001, Cramer test =0,79) and displacement or absence of conduction block lines (chi-square test =6,92, p=0,009, Cramer test =0,56) and prevents the CRT effect (OR =8,67, 95% CI, 1,05-71,57 p=0,03).Conclusion. Proximal LBBB is only one of the factors determining the effectiveness of CRT. Proximal LBBB may mask significant myocardial structural changes that prevent the CRT success.

Aim To identify risk factors for recurrence of atrial fibrillation (AF) following cryoballoon ablation (CBA). Material and methods This prospective study included patients with paroxysmal AF who had undergone CBA (141 patients, median age 60 years, 3% men). The evaluation prior to CBA included clinical instrumental parameters (electrocardiography (ECG), 24-h ECG monitoring, echocardiography, contrast-enhanced cardiac multispiral computed tomography). Also, possible intraoperative indexes that could affect the CBA effectivity, were evaluated. The postoperative follow-up duration was 12 months. Effectivity was assessed during in-person visits at 3, 6, and 12 months, when questioning of patients and 24-h ECG monitoring were performed. CBA was considered ineffective if the patient had recurrences of any atrial tachyarrhythmia longer than 30 sec after the end of the 3-month "blind" period. Results During the 12-month follow-up, recurrences of atrial tachyarrhythmia were observed in 46 (32.6%) patients. Patients with ineffective CBA more frequently had AF during the first 3 months (71.7% vs. 11.6%; p<0.001). Such patients had a history of multiple ineffective treatments with antiarrhythmic drugs (AAD), common pulmonary venous (PV) collector (41.3 % vs. 20.0%; p=0.008), and stroke/recurrent ischemic attacks (15.2 % vs. 5.2%; p=0.047). Multifactorial regression analysis showed that the factors of AF recurrence included common PV collector (relative risk (RR) 2.35; 95 % confidence interval (CI) 1.29-4.25; p=0.005), multiple ineffective AADs (RR 1.42; 95% CI 1.08-1.86; p=0.011), and early AF recurrence (RR 7.57; 95% CI 3.84-14.90; p<0.001). Conclusion Common PV collector and multiple ineffective AADs are risk factors of ineffective CBA. Early recurrences during the first 3 postoperative months are a significant risk factor of long-term AF recurrences.

AIM:Evaluation of the efficacy and safety of the modified refralon administration protocol for the relief of paroxysmal atrial fibrillation (AF).MATERIALS AND METHODS:The study included 39 patients (19 men, mean age 6312.8 years). All patients, after excluding contraindications in the intensive care unit, were injected intravenously with refralon at an initial dose of 5 mg/kg. If AF was preserved and there were no contraindications, after 15 min, repeated administration was performed at a dose of 5 mg/kg (total dose of 10 mg/kg). After another 15 min, while maintaining AF and the absence of contraindications, the third injection of the drug was performed at a dose of 10 mg/kg (total dose of 20 mg/kg). In the absence of relief and the absence of contraindications, another injection of refralon at a dose of 10 mg/kg was performed after another 15 min (in this case, the maximum total dose of 30 mg/kg was reached). After each injected bolus and before the introduction of the next one, the ECG parameters and the general condition of the patient were assessed. The patient was monitored for 24 hours to exclude the arrhythmogenic effect and other possible adverse events.RESULTS:Restoration of sinus rhythm (SR) was noted in 37 patients out of 39 (95%). Of these, 19 people (48.7%) had SR recovery after the administration of a minimum dose of refralone of 5 mg/kg. The effectiveness of the total dose of 10 mg/kg was 76.9%, the dose of 20 mg/kg was 89.7%, and the dose of 30 mg/kg was 95%. Only two patients did not recover HR after administration of the maximum dose of refralon 30 mg/kg. Pathological prolongation of the QTc interval (500 ms) was recorded in 5% of patients. Not a single case of ventricular arrhythmogenic action (induction of Torsade de pointes) has been reported. Bradyarrhythmias (pauses, bradycardia) were registered in 13% of cases, were of a transient nature.CONCLUSION:Refralon has a high efficiency of relief (95%) of paroxysmal AF, while in almost half of cases (48.7%), SR recovery is achieved using the minimum dose of refralon 5 mg/kg. Despite the prolongation of the QTc500 ms recorded in 5% of cases, none of the patients developed Torsade de pointes after administration of the drug.

Цель исследования. Изучить приверженность к ПАП-терапии (терапия путем создания положительного давления в дыхательных путях) и ее эффективность при длительном (> 12 месяцев) использовании, а также оценить влияние на характер течения фибрилляции предсердий (ФП) у больных синдромом обструктивного апноэ сна (СОАС). Материал и методы. В исследование включены 39 пациентов с ФП и СОАС, которые находились на ПАП-терапии более 12 месяцев. Возраст пациентов составил 65 лет (медиана), 90% были мужчины. До инициации ПАП-терапии 7 (18%) больных имели среднетяжелую, а 32 (82%) — тяжелую степень СОАС. 29 (74%) пациентов страдали пароксизмальной формой ФП и 10 (26%) — постоянной формой ФП. При изучении характера течения ФП проводились сбор анамнеза, анализ медицинской документации и определение режима антиаритми- ческой терапии. Дополнительно оценивалось количество проведенных катетерных аблаций, сохранение пароксизмального характера тече- ния ФП. Для оценки значимости клинических проявлений ФП использовалась шкала симптомов EHRA (European heart rhythm association — Европейской ассоциации специалистов по лечению нарушений ритма сердца). Оценка приверженности и эффективности ПАП-терапии проводилась путем считывания данных с внутренней карты памяти прибора. Для определения уровня дневной сонливости использовали шкалу сонливости Эпворта. Результаты. При анализе данных приверженных к ПАП-терапии (использование > 70% ночей, > 4 ч/ночь) оказалось 26 (67%) пациентов, а критерию эффективности ПАП-терапии (ИАГ < 5 соб./час) – 27 (69%). На фоне ПАП-терапии выявлено стойкое снижение ИАГ в среднем с 40 соб./час до 3,4 соб./час, р < 0,0001. Проведение ПАП-терапии привело к значимому снижению степени выраженности дневной сонливо- сти. У всех больных с пароксизмальным течением ФП сохранялись рецидивы аритмии, а трансформация ее в постоянную форму имела место у 17,6% больных. У приверженных к ПАП-терапии пациентов переносимость ФП по шкале EHRA улучшилась на 80,7%. Заключение. ПАП-терапия эффективна в долгосрочной перспективе в снижении степени нарушений дыхания во время сна и уровня днев- ной сонливости. На фоне ПАП-терапии и проводимого антиаритмического лечения сохраняется возможность рецидивов ФП и ее перехода в постоянную форму Aim. To study adherence to PAP therapy (positive airway pressure therapy) and it’s the long term (> 12 months) effectiveness and to investigate its possible effect on the course of atrial fibrillation (AF) in patients with obstructive sleep apnea (OSA). Material and methods. The study included 39 patients with AF and OSA, who used PAP therapy for more than 12 months. Median age was 65 years, 90% were men. Prior to PAP therapy initiation 7 (18%) patients had moderate OSA, and 32 (82 %) had severe OSA. 29 (74%) patients had paroxysmal AF and 10 (26 %) — permanent AF. The course of AF was assessed by medical history, analysis of antiarrhythmic therapy, catheter ablation procedures, maintenance of the paroxysmal form of AF. The EHRA (European heart rhythm association) scale was used to assess the significance of the AF clinical manifestations. Аdherence and effectiveness of PAP therapy was examined by data downloaded from the device’s internal memory. The Epworth Sleepiness Scale was used to determine the level of daytime sleepiness. Results. Analysis showed that 26 (67%) of patients were adherent to PAP therapy (use > 70% nights, > 4 h/night), and 27 (69%) met the PAP therapy effectiveness criteria. PAP therapy lead to a persistent decrease in apnea-hypopnea index (AHI) from 40 events/ h to 3,4 events/h, p < 0,0001. PAP therapy led to significant decrease of daytime sleepiness severity. Recurrences of arrhythmias persisted in patients with paroxysmal AF and its transformation into a permanent form was observed in 17,6% of patients. Tolerance of AF according to the EHRA scale improved by 80,7% in adherent to PAP therapy patients. Conclusion. PAP therapy has long-term effectiveness in the reduction of sleep respiratory disorders. Recurrence of AF and its transition to a permanent form was still possible on PAP therapy and antiarrhythmic treatment

AIM To study the effectiveness of prolonged use of PAP therapy (positive airway pressure therapy) in eliminating sleep respiratory disorders and associated cardiac conduction disturbances. MATERIALS AND METHODS We included 21 patients who were examined at the Myasnikov Institute of Clinical Cardiology, National Medical Research Center of Cardiology, regarding cardiac rhythm and conduction disturbances, as well as obstructive sleep apnea and who have been on PAP therapy for more than 12 months. The average age was 66.5 [63.5; 73.2] years, body mass index 33.0 [30.2; 38.5] kg/m2, apnea-hypopnea index 65.0 [59.0; 86.3]/h. At the time of analysis, 15 patients continued to use PAP therapy (mean time of use: 6.0 years [4.7; 9.2]) and 6 patients refused long-term use of PAP therapy, mean time to use PAP therapy until failure amounted to 2.82.1 years. RESULTS PAP therapy lead to a persistent decrease in apnea-hypopnea index of 63.6/h to 3.7/h was (p=0.0002). 86% of patients met the criteria for adherence to PAP therapy (use 4 hours/night, more than 70% of nights). Initially, before the use of PAP therapy, all cardiac conduction disorders were during sleep and exceeded 3 seconds, with fluctuations from 3.1 to 10.6 seconds. PAP therapy appeared to be effective in all patients: no asystoles, duration of more than 3 seconds, were detected. CONCLUSION In obstructive sleep apnea patients with concomitant nighttime cardiac conduction disturbances, the long-term use of PAP therapy is effective and with good adherence.

Introduction.As a significant number of patients with heart failure (HF) does not respond to cardiac resynchronization therapy (CRT), a lot of research has deservedly focused on optimization, and better patient selection. The ideal resynchronization depends on different factors, from device programming to heart features and left ventricle (LV) lead position. Analysis of the 12-lead electrocardiogram (ECG) is the most simple method which can provide important information on LV lead location, presence of scar at LV pacing site, and fusion of intrinsic activation or RV pacing with LV pacing.Purpose. To analyze the electrophysiological and structural heart features and their correlation with the ECG pattern during biventricular (BV) pacing in patients with HF and CRT devices.Methods. The study included 47 patients (mean age 62.3±8.9 years) with LBBB, QRS duration ≥ 130 ms, left ventricular ejection fraction (LVEF) ≤ 35%, heart failure (HF) NYHA II-IV despite optimal pharmacological therapy during months. All patients had undergone CRT-D implantation. Late-gadolinium enhancement-cardiovascular magnetic resonance (LGE-CMR), 12-lead ECG, non-invasive cardiac mapping (NICM) (with obtaining the zone of late LV activation (ZLA)) were undertaken prior to CRT devices implantation. NICM with cardiac CT and evaluation of LV lead position, ECG pattern during BV pacing (#1 - fusion complex with increased or dominant R wave, independent of QRS duration, #2- QS pattern with QRS duration normalization, and #3- QS pattern with increased QRS duration) were undertaken after CRT devices implantation. Response to CRT was estimated by echo and was defined as decrease in LV end-systolic volume by > 15% after 6 months of follow-up.Results. CRT was effective in 28 patients (59.5%). According to the results of NICM, zone of late LV activation more often was located at 5,6,11,12 segments, and LV pacing site - at 6,7,12 segments of LV. In the “response” group overlap of scar zone and zone of late LV activation was observed (p=0.005). The presence of scar tissue in the LV pacing site was associated with CRT non-response (p<0.001), and the pacing zone of late LV activation resulted in the best CRT response (p<0.001). The distance from the LV electrode to the zone of late LV activation was less in the “CRT response” group (33 [20;42] mm vs 83 [55;100] mm, p<0.001). The most beneficial ECG pattern during BV pacing was #2, and #3 was more often observed in the group “CRT non-response”; configuration #1 was intermediate between ECG patterns #2 and #3.Conclusions. A comprehensive examination, including the study of the structural and electrophysiological heart features is important for the optimal positioning the LV lead and subsequent CRT device programming. The simple analysis of the QRS pattern during BV pacing can show whether biventricular pacing is adequately performed and can reveal inadequate CRT programming and LV lead positioning.

Purpose. To assess and to compare the ventricular myocardium activation patern obtained by non-invasive epi- and endocardial mapping (NIEEM), as well as electrocardiographic (ECG) variants of lef bundle branch block (LBBB) and to estimate the value of these data for the success of cardiac resynchronization therapy (CRT).Materials and methods. Te study included 23 patients (mean age 59,6±9,9 years) with LBBB, QRS duration ≥ 130 ms, lef ventricular ejection fraction (LVEF) ≤ 35%, heart failure (HF) NYHA II-IV despite optimal pharmacological therapy during 3 month. All patients had undergone CRT-D implantation. Depending on presence or absence of LBBB ECG-criteria, proposed by Strauss D.G. et. al, patients were divided into 2 groups: 1group - strict LBBB, proposed by Strauss D.G. et. al. (n=14) and 2 group – other ECG morphologies of LBBB (n=9). NIEEM by the Amycard 01C system with an analysis of epi- and endocardial ventricular electrical activation was performed in all patients and 5 healthy volunteers (mean age 29±1,0years). Response to CRT was estimated by echo and was defned as decrease in lef ventricular (LV) end-systolic volume by > 15% afer 6 months of follow-up.Results. LBBB ECG-criteria, proposed by Strauss D.G. et. al, was detected in 14 patients (61% of all included). According to the results of NIEEM, these patients had more pronounced ventricular electrical uncoupling (VEU) (р=0,002). Most ofen the line of block was detected in the anteroseptal or posterolateral region of the LV. Te zone of late LV activation, which is the most optimal position for the LV pacing electrode, was located in the basal and middle segments of the lateral and posterior walls. Afer 6 months of CRT 15 patients (65%) were included in the "response" group, the remaining 8 patients (35%) formed the "non-response" group according to echo criteria. In the "response" group the morphology of the QRS complex more frequently met the criteria, proposed by Strauss D.G. et al, than other ECG variants of LBBB (12 vs. 3 respectively, p = 0.023). Initially, VEU was more pronounced in the "response" group (VEU 55 [51, 64] ms in the "response" group vs 22 [8, 38] ms in the "non-response" group).Сonclusions. LBBB ECG criteria, proposed by Strauss D.G., identify patients with delayed transseptal interventricular conduction due to complete LBBB, what is a good target for CPT. Identifcation of individual ventricular activation properties may help to reveal responders to CRT in patients with LBBB.

Aim. To compare the results of non-invasive activational mapping in patients with “idiopathic” ventricular arrhythmias (IVA) with the data on myocardial structure obtained by late enhancement magnetic resonance tomography (MRI).Material and methods. Twenty eight IVA patients, mean age 37 y. o. [26; 45], with ventricular arrhythmias of the heart (VA) of 2nd or higher grade by Lown, and 5 healthy volunteers (HV), mean age 29 [29; 30], underwent surface epiand endocardial non-invasive mapping (SEENIM) of the heart with the system for noninvasive electrophysiological investigation of the heart “Amicard 01C” with the analysis of duration of the activation-recovery interval (ARI) of the ventricles, and high resolution MRI (voxel 1,25x1,25x2,5mm) with delayed contrasting.Results. The number of VA in IVA group was 20196 [11479; 29834] for 24 hours. In 11 patients there were episodes of non-sustained ventricular tachycardia (VT). By SEENIM, predominating morphological type of ventricular ectopic activity in 22 patients sourced from the right ventricle myocardium (RV), of those in 20 from outflow tract of the LV (OTLV). There was significantly prolonged ARI in OTLV patients with IVA comparing to HV (p<0,05). In IVA and non-sustained ventricular tachycardia patients, by contrast MRI of the heart, in LV myocardium there were small foci of contrast retention found. There was no correlation of the areas of contrast retention and topography of VA sources.Conclusion. In most of IVA patients the source of VA was outflowing tract of the RV. The revealed prolongation of the ARI of this area in IVA patients can be an important factor of IVA onset. Small foci of LV fibrosis, found in late enhancement MRI of the heart and episodes of so called idiopathic VT, might be the earliest presentation of the “tachycardiopathy” at the step of pathology development when there are no signs of LV dilation.

We present in this article 2 cases of successful pharmacological restoration of sinus rhythm by a new class III antiarrhythmic drug refralon in patients with obesity and persistent atrial fibrillation. In both cases, the effective use of refralon was preceded by repeated ineffective attempts of electrical cardioversion. In the article we discuss the role of obesity as the factor leading to a substantial increase of transthoracic electrical resistance, and thus significantly reducing the probability of sinus rhythm restoration by means of electrical cardioversion. The clinical examples described in this article clearly show that the use of refralon may represent a unique clinical alternative to electrical cardioversion for sinus rhythm restoration in patients with persistent atrial fibrillation, and in some cases where the success of electrical cardioversion is obviously questionable, like in patients with severe obesity, the use of refralon seems preferable.

OBJECTIVE:This study aimed to assess the level of anti-1-adrenergic receptor autoantibodies in patients with ventricular arrhythmias with no signs of organic heart disease and with presence of cardiovascular pathology in comparison with a group of healthy volunteers. MATERIAL AND METHODS:The study included 44 patients with ventricular arrhythmias with no signs of organic heart disease ("idiopathic"), 34 patients with diagnosed dilated cardiomyopathy (DCM) of inflammatory origin, 35 patients with coronary heart disease and ventricular arrhythmias, 12patients with coronary heart disease with no ventricular arrhythmias, and 19 healthy volunteers (control group). The level of autoantibodies against the 1-adrenergic receptor was determined by the developed competitive cell-based enzyme-linked immunosorbent assay (ELISA) and by the standard ELISA using peptides corresponding to the second extracellular loop of the 1-adrenergic receptor. RESULTS:Elevated level of autoantibodies detected by a competitive cell-based ELISA was observed in 62% of patients with DCM compared to 21% of healthy volunteers (p=0.0006). In patients with "idiopathic" ventricular arrhythmias, the level of 1-adrenergic receptor autoantibodies was lower than in healthy subjects (p=0.003). Coronary heart disease patients with or without ventricular arrhythmias exhibited no differences from the control group. The number of significantly positive signals in peptide-based ELISA did not exceed 10% in any of the groups. No correlation between the data from competitive cell-based ELISA and peptide-based ELISA was found. CONCLUSIONS:This study demonstrated that competitive cell-based ELISA technique can be applied for detection of 1-adrenergic receptor autoantibodies. The results in DCM patients generally correspond to the expected. Decreased level of autoantibodies in patients with "idiopathic" ventricular arrhythmias indicates that this disease is related to changes in the immune system. Such relation is not observed in the case of coronary heart disease patients.

This article reviews pathogenic mechanisms that underlie idiopathic cardiac rhythm and conduction disturbances. It focuses on the role of the various components of the inflammatory response of the myocardium, particularly on the autoimmune factors and fibrosis. Identification of potentially reversible autoimmune or inflammatory factors in the pathogenesis of cardiac conduction disturbances may be useful in predicting the development of the disease, serve as a rationale for more careful monitoring of these patients, and may become a target for new therapeutic approaches.

Aim. To identify the most promising epitopes that simulate various sites β1-adrenergic and M2-cholinergic receptors, and to evaluate their possible contribution to the development and maintenance of cardiac arrhythmias, particularly idiopathic ventricular arrhythmia. Material and methods. Patients with ventricular arrhythmias without organic cardiovascular disease (the study group; n=70) were included in the study. The control group consisted of 20 healthy volunteers. Evaluation of levels of antibodies to antigenic determinants, modeling various sites β1-adrenergic and M2-cholinergic performed in all patients. Causal treatment with clarithromycin and valacyclovir performed in part of patients. Results. Antibodies to different peptide sequences of β1-adrenergic and M2-cholinergic receptors have been identified in 25% of main group patients. A direct correlation between the frequency of episodes of ventricular tachycardia and IgG levels to MRI-MRIV (p=0.02) revealed. Increase in titre of antibodies to β1-adrenoceptors, to a peptide sequence β8 (p=0.02), and lower titers of antibodies to the M2 acetylcholine receptor — chimera MRI-MRIV IgM (p=0.06) and ARI-MRIV IgM (p=0.07) were observed when assessing the efficacy of the therapy in the causal dynamics in the group of "untreated" patients. IgG titer reduction of ARI-MRIV (p=0.02), which is 4 times out of 10 with reduction of ventricular ectopic activity , recorded after valacyclovir therapy. Clarithromycin therapy on the level of antibodies exerted no significant effect. Conclusion. Possible involvement of antibodies to β1-adrenoceptor and M2-cholinergic receptors in the development of idiopathic ventricular arrhythmias demonstrated. The relationship between the frequency of episodes of ventricular tachycardia and levels of antibody titers to M2-cholinergic receptors found. Attempt of causal treatment, depending on the possible mechanisms of the autoimmune process is executed. Further studies to confirm or refute the results to the larger sample of patients are needed.

In 35 patients (pts) with dilated cardiomyopathy (DCM) the cardiovascular magnetic resonance (CMR) data in combination with the assessment of the level of autoantibodies to beta(1)-adrenergic receptor (beta(1)-AAbs) and M-2-muscarinic receptor (M-2-AAbs) was analyzed. beta(1)-AAbs (IgG) were detected in serum of 68.6% patients, 31.4% of patients were M-2-AAbs (IgG) positive. CMR revealed late gadolinium enhancement (LGE) in 43% of patients. Presence of focal fibrosis in myocardium (persistence of LGE according to CMR) and detection of beta(1)-AAbs was closely associated with presence of ventricular arrhythmias. These findings allow using CMR data and the level of beta(1)-AAbs in determination of risk of ventricular arrhythmias in patients with left ventricular dysfunction including DCM.