Atrial remodelling comparison after maze-3 and cryo-maze procedures in combined cardiac interventions: a retrospective study

Background. The maze procedure aims to eliminate atrial fibrillation (AF), restore sinus rhythm (SR) and atrial contractility. However, conflicting evidence exists regarding the extent of atrial remodelling in various techniques, which directed the focus of our study.Objectives. An atrial remodelling comparison after a cut-and-sew maze-3 surgery and its biatrial cryo-maze modification using 2D echocardiography.Methods. The study is a retrospective uncontrolled interrupted two-cohort time-series trial, with patients selected by pseudorandomisation according to a normal sinus rhythm-maintaining AF surgery method. A total of 217 maze-3 and 113 cryo-maze combined cardiac interventions have been performed within 2012–2021. The interventions included valve repair, coronary artery bypass grafting and their combination. Due to differences in long-term follow-up, the cohorts were pseudorandomised to select by 50 restored vs. maintained sinus rhythm patients using a nearest-neighbour classifier coupled with logistic regression. Mean follow-up period was 6 (1–17) months. The patients had paroxysmal, persistent and longstanding persistent AF. Echocardiography values prior to and long-term post-surgery were further analysed to determine the atrial remodelling dynamics. Results. A statistically significant atrial volume reduction is evident in a long-term within-cohort comparison. Meanwhile, a statistically more pronounced remodelling is observed between cohorts after maze-3 procedure. The cohort 1 vs. 2 estimates are: mean left atrial volume 120/125 mL3 (p = 0.011), left atrial size in apical view 52/53 mm (p = 0.023), right atrial size in apical view 58/62 mm (p = 0.004), right atrial size in parasternal short axis view 43/45 mm (p = 0.004), right atrial area in apical 4-chamber view 25/28 cm2 (p = 0.007). Maintained atrial pacing patients had positive systolic atrial function recovery rates (E/A ratio increased to average 1.5) in the long-term in both comparison cohorts.Conclusion. Remodelling is biatrial after all the maze procedures compared. A more pronounced atrial volume reduction occurs after maze-3 surgery. The presence of sinus rhythm is facilitated by cardiac conduction leading to mechanical and electrical remodelling of the atria

СЕРДЕЧНАЯ РЕСИНХРОНИЗИРУЮЩАЯ ТЕРАПИЯ. ФОРМИРОВАНИЕ ПОКАЗАНИЙ И СОВРЕМЕННЫЕ ПОДХОДЫ К ПОВЫШЕНИЮ ЭФФЕКТИВНОСТИ МЕТОДА

The article provides new insights to cardiac resynchronization therapy (CRT), a method of treating chronic heart failure with cardiac biventricular pacing. The article covers the history of its development starting with the first attempts to eliminate heart dyssynchrony up to the present advances. Over the last decades, CRT has significantly improved, including both implantable devices and electrodes, and current CRT guidelines and indications. The article discusses serial changes in indications and selection criteria for patients based on the results of the recent clinical trials assessing its effectiveness. Evidence-based knowledge is presented for the CRT application in the routine clinical practice. Novel approaches and technologies aimed at improving the effectiveness of CRT are presented.Статья посвящена сердечной ресинхронизирующей терапии (СРТ) – методу лечения хронической сердечной недостаточности посредством бивентрикулярной кардиостимуляции. В статье рассматривается история развития метода от первых попыток устранения диссинхронии сердца до настоящего времени. За последние 20 лет метод претерпел существенное изменение как в плане технического совершенствования имплантируемых устройств и электродов, так и в плане формирования современных показаний к его применению. В статье изучается динамика изменений показаний и критериев отбора пациентов на основе результатов клинических исследований по изучению эффективности метода. Приводятся современные показания для применения СРТ и существующая доказательная база, лежащая в их основе. Описываются современные подходы и технологии, направленные на повышение эффективности метода СРТ

Оценка сократимости и ремоделирования предсердий после процедуры «Лабиринт-3» при сочетанных вмешательствах на сердце

Highlights. The most important goal of atrial fibrillation surgical treatment is to eliminate the arrhythmia in order to restore atrial contractility and improve their transport function. Our study showed positive dynamics of atrial contractility and remodeling after the maze-3 procedure against the background of a regular heart rhythm restoration. The study of sinus rhythm predictors maintenance and recovery of atrial transport function will help to make patient selection more personified.Aim. Evaluation of atrial contractility and remodeling after the maze-3 procedure with combined interventions on the heart.Methods. The analysis of 217 combined surgical interventions was carried out, where a maze-3 was used to treat atrial fibrillation (AF). The operations were performed in our center from 2012 to 2016. Key points of the study: rhythm after surgery and echocardiographic control in the long-term follow-up in order to determine the dynamics of atrial contractility and volumes. The average follow-up period was 47 (1–100) months. 40 (18.4%) patients had paroxysmal, 38 (17.5%) persistent, 139 (64.1%) long-term persistent AF. The mean AF duration before surgery was 27.4 months (1–200 months). The indications for the maze-3 procedure were: ineffectiveness of antiarrhythmic therapy, the need to perform combined cardiac procedures. We used standard statistical research methods with one – and multivariate logistic regression.Results. In the long-term follow-up, sinus rhythm (SR) persists in 79% of patients. In the long-term follow-up, in this group of patients, the left atrial contractility was  restored  from  76%  to  91%,  while  the  biatrial  contractility  increased from 82 to 96%. Shorter AF duration before surgery was a positive predictor of SR recovery and atrial contractility (p = 0.005), while pulmonary artery pressure and patient age negatively affected these indicators (p = 0.041 and p = 0.038, respectively). The presence of SR early after surgery was not a significant predictor of AF freedom. At the same time, according to the long-term observations, patients maintaining a regular atrial heart rate had positive indicators of atrial systolic function restoration and a positive dynamics of a decrease in atrial volumes.Conclusion. SR and restoration of left atrial contractility are two interrelated goals of the maze procedure. The negative factors associated with the failure of surgical treatment of AF are increased pressure in the pulmonary artery, long-term AF before surgery, and the age of patients.Основные положения. Наиболее важная цель хирургического лечения фибрилляции предсердий – устранение аритмии для восстановления сократимости предсердий и улучшения их транспортной функции. В исследовании показана положительная динамика сократимости и ремоделирования предсердий после процедуры «Лабиринт-3» на фоне восстановления регулярного ритма сердца. Изучение предикторов удерживания синусового ритма и восстановления транспортной функции предсердий способствует более персонифицированному отбору пациентов.Цель. Оценка сократимости и ремоделирования предсердий после процедуры «Лабиринт-3» при сочетанных вмешательствах на сердце.Материалы и методы. Проведен ретроспективный анализ 217 сочетанных хирургических операций, при которых для лечения фибрилляции предсердий (ФП) применена техника «Лабиринт-3». Процедуры выполнены в ФГБУ «ФЦВМТ» Минздрава России (г. Калининград) с 2012 по 2016 г. Ключевые точки исследования: ритм сердца после операции и эхокардиографический контроль в отдаленные сроки наблюдения с целью определения динамики сократимости и объемов предсердий по ЭхоКГ-показателям. Средний период наблюдения составил 47 (1–100) мес. Мужчин – 145 (63%), средний возраст – 65 (45–82) лет. 40 (18,4%) пациентов имели пароксизмальную, 38 (17,5%) – персистирующую, 139 (64,1%) – длительно персистирующую форму ФП. Средняя продолжительность ФП до операции составила 27,4 (1–200) мес. Показаниями для выполнения процедуры «Лабиринт-3» являлись неэффективность антиаритмической терапии, необходимость сочетанных процедур на сердце. Применяли стандартные статистические методы исследования с проведением одно- и многофакторной логистической регрессии.Результаты. В отдаленные сроки наблюдения синусовый ритм сохранялся у 79% пациентов. Также у этой группы больных зарегистрировано восстановление сократимости левого предсердия с 76 до 91%, в то время как биатриальная сократимость увеличилась с 82 до 96%. Меньшая длительность ФП до операции являлась положительным предиктором восстановления СР и сократимости предсердий (р = 0,005), в то время как давление в легочной артерии и возраст пациентов отрицательно влияли на данные показатели (р = 0,041 и р = 0,038, соответственно). Наличие СР в ранние сроки после операции не являлось значимым предиктором свободы от ФП. При этом больные с удерживанием регулярного предсердного ритма сердца, по данным долговременных наблюдений, имели положительные показатели восстановления систолической функции предсердий и динамику уменьшения их объемов.Заключение. Синусовый ритм и восстановление сократимости предсердий – две взаимосвязанные цели процедуры «Лабиринт». Негативными факторами, ведущими к неуспеху хирургического лечения ФП, являются повышенное давление в легочной артерии, длительно существующая ФП до операции и старший возраст пациентов

SEPARATE CLINICAL CASES WITH EFFICIENT CRT THERAPY

We demonstrated findings regarding left ventricle electrode implantation with CRT, and suggested alternative implantation version, and performed analysis of therapy efficiency in cases with transseptal implantation technique

Analysis of arrhythmic episodes in patients with implanted cardioverter defibrillators and a high risk of sudden cardiac death

Aim. To analyze arrhythmic events, according to the programming data of implanted cardioverter defibrillators (ICD), with the view of minimizing shock effects.Material and methods. The study included examination materials of 207 patients with implanted ICD/cardiac resynchronization therapy (CRT) devices. Patients were divided according to the types of implanted devices: 65 patients (31%) — CRT, 75 patients (36%) — single-chamber ICD, 67 patients (33%) — dual-chamber ICD. In the patient structure there were 168 patients (81%) with primary and 39 patients (19%) with secondary prevention of sudden cardiac death (SCD). In order to minimize the amount of shock effects applied, the following defibrillator programming techniques were used: prolongation of the duration of tachycardia detection in the ventricular fibrillation (VF) zone from the nominal parameters and changing the plan of applying antitachycardia stimulation (ATS) in VF zone (the number of stimuli in the exposure pack was increased and the stimulation interval was shortened by 10-20% in comparison with the initial parameters). To stop hemodynamically insignificant monomorphic ventricular tachycardia, shocks in the stopping pattern were disabled and only ATS was activated. Statistical processing of the obtained data was carried out using the “IBM SPSS Statistics 20” software.Results. The probability of shock and ATS effects in patients from the primary SCD prophylaxis group significantly increases in the presence of: ischemic cardiomyopathy (p=0,006) and severe ventricular extrasystoles (p=0,029).The absence of amiodarone therapy significantly increases the risk of shock effects in patients with implanted ICD for primary (p=0,002) and secondary prevention of SCD (p=0,02). In the vast majority of cases, appropriate shock effects were inflicted on patients with coronary artery disease and a history of myocardial infarction. On the contrary, in patients with dilated cardiomyopathy, clinically inappropriate shocks prevailed, most often performed on atrial fibrillation (р<0,001). In all cases of life-threatening ventricular arrhythmias, the effects of ICD and CRT were effective for their relief. There were no suddenly dead patients in the study. There were no negative effects of the proposed programming techniques. Against the background of increased tachycardia detection time, 48% of all arrhythmias stopped on their own without worsening. In patients with CRT devices, founded and unfounded responses were significantly less common than among patients with ICD. The main causes of inappropriate responses were: atrial arrhythmias in the VF detection zone (р<0,001), standard detection time in the VF zone (р<0,001) restrictions on the use of atrial ventricular arrhythmias discriminator (р<0,018).Conclusion. The prolongation of the tachycardia detection duration in the VF zone and the optimization of ATS lead to a decrease in shock ICD effects

Investigation of thermal conductivity coefficient during freezing

The use of a measuring cell for the device for determining the thermal conductivity of agricultural products of the proposed design allows to increase the accuracy of measuring the thermal conductivity of agricultural products