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.

Introduction. Determination of ventricular and supraventricular arrhythmias with left bundle branch block morphology (LBBB) seems to be one of the most complex diagnostic tasks when P waves are not clearly identifiable on 12-lead ECG. Previously described criteria for differential diagnosis of wide QRS arrhythmias had low accuracy especially for patients from various clinical groups and also those taking antiarrhythmic drugs. When patient’s clinical data, medical history or physical examination results are not available the number of misdiagnosis may increase leading to improper treatment. Therefore, development of new temporal and amplitude based characteristics of wide QRS complex arrhythmias with LBBB morphology in patients of any clinical groups is an important task.

Methods. Twenty-eight consecutive patients with wide QRS premature beats and LBBB morphology identified by 24-hour and long-term ECG monitoring (ZAO “INCART”, Russia) were enrolled in the study. Fourteen patients had premature atrial contractions (PAC) and fourteen patients had premature ventricular contractions (PVC) during sinus rhythm. For each patient 10 typical single wide QRS complexes in 12 ECG leads were analyzed. The duration of QRS complexes, time intrinsic deflection (TID) and electrical axis of the heart were determined automatically in 12 leads ECG using KT Result 3 software (ZAO “INCART”, Russia). The experts assessed morphology of the QRS complexes and transition zone location in leads V1-V6. ROC analysis with optimal cut-off value level evaluation as well as calculation of sensitivity (SV), specificity (SP) and diagnostic accuracy (ACC) were performed for qualitative and quantitative assessment of diagnostic value of PAC and PVC amplitude and temporal characteristics. Comparison of diagnostic values of wide QRS complex morphological and temporal criteria was performed based on the AUC difference and the corresponding p-value assessment.

Results. The results of study found out that V5, V1 leads were more informative for assessment of QRS complex morphology and duration while V1 and V4 leads were more informative for TID calculation in differential diagnosis of wide QRS complexes arrhythmias with LBBB morphology. PAC with aberrant conduction had the following characteristics: TID < 68 ms in V1 lead and TID < 62 ms in V4 lead; QRS < 136 ms; transition zone in the leads V5, V6; QS, rS or RS complexes (with S> R) with low-amplitude r/R waves in leads V1-V4; electric axis of the heart less than 80° in standard leads. In all cases PVCs were characterized by QRS > 160 ms and TID > 88 ms in V1-V6 leads.

Conclusions. New various criteria which can improve differential diagnosis of wide QRS complexes with LBBB morphology were identified in this study. These criteria should be tested in a larger group of patients with various forms of wide QRS complex arrhythmias and different PVC localizations including information of structural heart diseases due to the small sample size in this study.

Conflicts of Interest: Viktor M. Tikhonenko - CEO (Director General) of the Institute of Cardiology Technics (INCART), Saint-Petersburg, Russia.

Objective. To evaluate the effectiveness of epicardial bipolar radiofrequency ablation (RFA) of pulmonary vein ostia (PV) in comparison with its being combined with amiodarone administration for post-CABG atrial fibrillation (AF) prevention.

Methods. A single-centre, prospective randomized study (PULVAB), including 96 CAD patients with no history of AF, was conducted between January 2015 and December 2018. Group 1 (control; n=34) had standard CABG alone. Group 2 (n=29) received RFA of PV as an adjunct to CABG for prevention of postoperative AF (POAF). Group 3 patients (n=33) had RFA at the time of CABG and were given amiodarone. Allocation was concealed using sequentiallynumbered opaque envelopes. The efficacy and safety of RFA concomitant with CABG were assessed, as both performed independently and combined with amiodarone administration, as well as intra-and postoperative course.

Results. No differences were seen in operation length (p=0.937), cardiopulmonary bypass (CPB) or the aorta clamping times (р=0.377 and p=0.072, respectively). The study groups (CABG, CABG-RFA, CABG-RFA-amiodarone) did not differ statistically in the number of shunts placed - 3.17±0.61, 3.10±0.51 and 2.94±0,6 (p=0,121). No significant difference was noted in RFA duration between Groups 2 and 3 - 11.7±3.7 and 11.4±6.3 min, respectively (p=0,834).

AF was found to occur most commonly at postoperative days two or four. The isolated CABG surgery group patients developed POAF most often of all (32,4%). The incidence of POAF was lower after RFA concomitant to CABG - 20.7% (р=0,29). A significant difference was identified in POAF incidence between Groups 1 and 3- 32.4% and 6.1%, respectively (p = 0.0065). Differences between Groups 2 and 3 proved not to be statistically significant (р= 0,086). Sinus rhythm in most of those who had developed arrhythmias was restored by pharmacological cardioversion except for three patients (one in each group). At discharge, 97.1% , 96.7% and 97% of the subjects in Groups 1, 2 and 3, respectively, exhibited sinus rhythm (p>0,05).There was no in-hospital mortality in any of the groups. Neither were there any wound complications, reoperations, perioperative myocardial infarction or cerebral circulatory disorders observed. No difference was revealed in the severity and frequency of renal or respiratory failure. The mechanical lung ventilation time and duration of stay in the ICU in the isolated CABG group were shown to be increased as compared with the CABG-RFA and CABG-RFA-amiodarone groups (p<0.05).

Conclusion. The evidence from the pilot study (PULVAB) suggests that bipolar ablation of PV does not significantly complicate CABG, while being combined with amiodarone administration for prevention of rhythm disorders it significantly reduces the incidence of POAF. The in-hospital incidence of POAF tended to decrease, which was not statistically significant, though. Evaluating the efficacy of RFA concomitant with CABG, as performed independently, invites further investigation with more data analysis.

Objective: complex pharmacoeconomic evaluation of warfarin replacement with rivaroxaban one of the direct oral anticoagulant (DOAC) for the treatment of patients with non-valvular atrial fibrillation and high risk of thromboembolia with poor international normalized ratio control.

Materials and methods: A pharmacoeconomic model was designed to evaluate clinical outcomes of rivaroxaban therapy in compare with warfarin (with poor international normalized ratio control), economic impact was also calculated using budget impact analysis. Direct medical costs included drug costs, inpatient costs and costs of patient rehabilitation with cardiovascular complications. Moreover, indirect costs were simulated, including Gross Domestic Product loss due to disability or mortality of patients. Results were calculated on total number of patients from Russian Federation with non-valvular atrial fibrillation and high risk of thromboembolism, receiving rivaroxaban and warfarin (total of 278,175 patients). Patients with non-valvular atrial fibrillation on other anticoagulant therapies (130,305 patients) were not included in the analysis. Modeling horizon was 12 months.

Results: in the analyzed population replacement of warfarin with poor international normalized ratio control with rivaroxaban makes it possible to additionally prevent 3,778 stroke events (-33% in compare with warfarin), 170 events of systemic thromboembolisms (-31%), 1,977 events of fatal bleeding (-11%) and 247 events of myocardial infarctions (-6%). Generally, patients transfer to rivaroxaban therapy reduces mortality by 30% (2,908 cases). Budget impact analysis demonstrated, that despite of the increased drug therapy costs by 2,306.1 million RUR, replacement of warfarin in the part of patients with rivaroxaban reduces costs, related to the complications treatment by 543.0 million RUR, rehabilitation costs - by 461.6 million RUR, INR control costs - by 480.3 million RUR, decline in GDP due to disability and mortality - by 2,988.5 million RUR. Thereby, replacement of patients with poor international normalized ratio control from warfarin to rivaroxaban reduces costs, related to the complications treatment of atrial fibrillation and GDP loss by 2,174.0 million rub.

Conclusion: Warfarin replacement with rivaroxaban in patients with non-valvular atrial fi brillation and high risk of thromboembolism with poor international normalized ratio control is the most efficient from clinical and economic points.

The causes and clinical significance of the “wide” QRS complexes are considered, the results of the first studies aimed at determining the criteria and the development of algorithms for differential diagnosis of tachycardia occurring with the “wide” QRS complexes are analyzed.

A review of the main clinical studies on the effectiveness and safety of using alternative techniques for implanting a left ventricular electrode for cardiac resynchronization therapy is presented.

A case report of differential and topical diagnosis of ventricular tachycardia from right ventricular outflow tract endocardial surface with ventriculoatrial retrograde conduction using non-invasive electrocardiographic imaging is presented.

Conflicts of Interest: M.Chmelevsky - clinical specialist EP Solutions SA, S.Zubarev and M.Budanova - consultants EP Solutions SA.

Sergey Alekseevich Bakalov passed away.

III Saint-Petersburg Arrhythmia Forum “Arrhythmology Without Frontiers: From An Experimental Laboratory To Clinical Recommendations”.