Svetlana Yu. Kashtanova

Aim. To analyze myocardial work in cardiac resynchronization therapy (CRT) and to determine the factors influence its positive dynamics. Materials and methods. Global longitudinal strain (GLS) and myocardial work parameters including global constructive work (GCW), global wasted work (GWW), global work index (GWI) and global work efficiency (GWE) were analyzed in addition to standard transthoracic echocardiography (TTE) in 60 patients (mean age 61±10 years, 36 male) with left bundle branch block (LBBB), chronic heart failure (HF 2 [2; 3] FC (NYHA), decreased left ventricular ejection fraction (LF EF=28 [23; 31] %) before and 6 months after CRT implantation.. In all patients the segments with maximum and minimum WI value were determined and the difference in segments with maximal and minimal WI (Max-Min WI), as the indicator of myocardial work asymmetry was calculated. Results. CRT led to reverse cardiac remodeling in 44 (73.3%) patients; clinical stabilization without positive TTE dynamics – in 11 (18.3%) patients, worsening or death – in 5 (8.3%) patients. In both groups of reverse remodeling and clinical stabilization CRT resulted in GWW reduction and thus GWE and GWI enhancement. However, the decrease in GWW in these patients is not accompanied by an increase in GCW and GLS, in contrast to patients with reverse remodeling, who developed statistically significant change in GCW and GLS during CRT. Patients with worsening or death were characterized by a minimal decrease in GWW in CRT (62,0 [9,7; 133,7] vs 149,5 [92.8; 206,2] mmHg% in patients with reverse remodeling and clinical stabilization; p=0,035). Max-Min WI turned out to be directly related to the LV EF change in CRT (rxy=0,336; p=0,017) that makes this value to be one of possible predictors of reverse remodeling during CRT. Conclusion. Wasted myocardial work can serve a contractile reserve, which represent a target for CRT. Its mobilization and decrease can lead to stable clinical status in patients even in the absence of reverse myocardial remodeling.

Aim. To evaluate myocardial function in different groups of patients with left bundle branch block (LBBB) and the LBBB "model" — right ventricular pacing (RVP).Material and methods. Global longitudinal strain (GLS) and myocardial function parameters, such as global constructive work (GCW), global wasted work (GWW), global work index (GWI), and global work efficiency (GWE), were measured in 25 patients with dilated cardiomyopathy (DCM) and LBBB (DCM-LBBB group), 20 patients with DCM and a narrow QRS complex (DCM-nonLBBB group), 15 patients with LBBB developed after transcatheter aortic valve implantation (TAVI LBBB group), 12 patients with idiopathic LBBB (I-LBBB group), 27 patients with permanent RVP, and 10 healthy volunteers (HVs). The segments with maximum and minimum GWI were determined in all patients.Results. The GLS, GWI and GCW values were comparable in the I-LBBB and RVP groups, and were significantly lower in the TAVI-LBBB and both DCM groups than in HVs (p=0,049, 0,006, 0,025; pConclusion. Despite the fact that all patients with an electrical activation pattern corresponding to LBBB are characterized by significant wasted work, its contribution to the global myocardial work is significant only in patients with DCM. Lost work does not lead to a decrease in constructive work in patients with I-LBBB and RVP and normal left ventricular systolic function.

We present a clinical case of familial LMNA-associated cardiomyopathy, confirmed by whole genome sequencing. The typical for lamin-associated cardiomyopathy indicates pathogenic nature of the mutation in the first exon of LMNA gene, previously considered a mutation of unknown clinical significance. The presented clinical case demonstrates a radical change in patient treatment strategies in the context of the widespread introduction of molecular genetic research methods into practice.

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, pConclusion. 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.

Изучение динамики биомаркеров NT-proBNP и sST2 для прогнозирования одиночных желудочковых тахиаритмий и “электрического шторма” у больных с систолической сердечной недостаточностью и различными имплантированными устройствами

Patients with dilated cardiomyopathy (DCM) often have intraventricular conduction disorders, which contribute to aggravation of heart failure, are progressive in most cases and can specify the prognosis of the disease. Paroxysmal supraventricular arrhythmias in such patients proceed with severe clinical manifestations, often accompanied by hemodynamic instability and syncope. A case report of patient (59 years old) with DCM, reduced left ventricular ejection fraction (35-37%), left bundle branch block, and paroxysmal orthodromic reciprocating tachycardia is presented. When an electrode was inserted on the right ventricular (RV) apex during the radiofrequency ablation, a third-degree atrioventricular (AV) block was recorded. This was maintained during the operation and was recurrent when trying to remove the electrode from the RV apex, and therefore there was a need for temporary and then permanent cardiac pacing therapy. Given DCM, reduced left ventricular ejection fraction, left bundle branch block, and the expected high percentage of RV pacing, a decision was made to implant a cardiac resynchronization therapy defibrillator. The literature review considers risk factors for formation of third-degree AV block during cardiac catheterization, methods of its prevention, as well as discusses the prognostic significance of catheter-induced conduction disorders, and indications for temporary and permanent cardiac pacing therapy.

Aim. To assess the effect of the size and pattern of myocardial structural injury, determined by magnetic resonance imaging (MRI), on response to cardiac resynchronization therapy (CRT) in patients with ischemic and non-ischemic heart failure (HF).Material and methods. Forty seven patients with ischemic and non-ischemic HF (age 62,3±8,9 years (mean±SD), 44,6% females and 55,4% males), left ventricle (LV) ejection fraction 130 ms, and sinus rhythm were included in the study. Late-gadolinium enhancement-cardiovascular magnetic resonance (LGE-CMR) was undertaken to evaluate myocardial scar prior to CRT devices implantation. All CMR analysis was performed on CVI42 software. According to signal intensity, fibrosis zone and “grey zone” were defined for quantitative analysis (proportion and mass) of injury. Scar zone included fibrosis zone and “grey zone”. Scar location was assessed using a 16-segmentLV model. Response was defined as a reduction inLV end systolic volume of >15% at 6 months follow-up and HF functional class amelioration.Results. In nonresponse group there was significantly higher proportion and mass of total scar (median 4% [2,5; 19] vs 24% [7; 44], p=0,012,6 g [3,5; 32,5] vs41 g [8; 86], p=0,013)), fibrosis zone (median 0% [0; 3,5] vs 8% [0; 19], p=0,01,0 g [0; 6] vs14 g [0; 34], p=0,014) and “grey zone” (4% [2,5; 15] vs 15% [7; 23], p=0,018,6 g [3,5; 27,5] vs23 g [8; 39], p=0,25). Response proportion in non-ischemic HF patients was higher than in ischemic HF patients (78,5% vs 28,5%, pConclusion. Response to CRT is significantly higher in non-ischemic than in ischemic HF patients. Nonresponse to CRT is associated with posterolateral scar, regardless of the HF origin. In patients with non-ischemic HF, size of fibrosis zone is lower in the responder group. In patients with ischemic HF, size ofLV structural injury does not affect the CRT efficiency, but lateral scar is associated with CRT nonresponse.

У пациентов с дилатационной кардиомиопатией (ДКМП) часто развиваются нарушения внутрижелудочковой проводимости, которые способствуют усугублению клинического течения сердечной недостаточности, в большинстве случаев имеют прогрессирующее течение, и могут определять прогноз заболевания. Пароксизмальные суправентрикулярные аритмии у таких больных протекают с тяжелыми клиническими проявлениями, нередко сопровождаются гемодинамической нестабильностью и синкопальными состояниями.Представлен клинический случай пациентки К., 59 лет с ДКМП, сниженной фракцией выброса левого желудочка (35-37%), блокадой левой ножки пучка Гиса и пароксизмальной ортодромной реципрокной тахикардией. При постановке диагностического электрода в верхушку правого желудочка в ходе процедуры радиочастотной аблации добавочного пути проведения у пациентки было отмечено возникновение полной поперечной блокады.Сохранение полной поперечной блокады в течение операции, ее рецидивы при попытках удаления электрода из верхушки правого желудочка потребовали обеспечения временной, а затем постоянной электрокардиостимуляции. Учитывая ДКМП, со снижением фракции выброса левого желудочка, наличие блокады левой ножки пучка Гиса и высокий ожидаемый процент стимуляции правого желудочка, принято решение об имплантации сердечного ресинхронизирующего устройства с функцией дефибриллятора. В обзоре литературы рассмотрены факторы риска развития полной поперечной блокады в ходе катетеризации сердца, возможности профилактики этого опасного осложнения, обсуждены прогностическая значимость катетер-индуцированных нарушений проводимости, показания к временной и постоянной электрокардиостимуляции.