No abstract

2017;6(4):80-88. D O I:10.17802/2306-1278-2017-6-4-80-88 ng| ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

The aim of this paper is to evaluate the effect of pulmonary vein (PV) morphometric characteristics and spatial orientation on the results of cryoballoon ablation (CBA). Methods: A randomized, prospective, single-center controlled study was conducted, enrolling 230 patients with drug-refractory atrial fibrillation (AF). We compared procedural and long-term outcomes in patients who underwent their first procedure of pulmonary vein isolation (PVI) for AF with either radiofrequency ablation (RFA) (n = 108) or CBA (n = 122) and assessed their interaction with the different pattern of PV anatomy, morphometric characteristics, and spatial orientation. The primary efficacy endpoint was any documented atrial arrhythmia recurrence (AF, atrial flutter, or atrial tachycardia) lasting over 30 s during a 12-month follow-up after a 90-day blanking period and discontinuation of antiarrhythmic drugs. The procedure’s endpoint was the achievement of PVI. Before the intervention, all patients underwent computed tomography (CT) to assess the PV anatomical variant, maximum and minimum diameters of the PV’s ostia, their cross-sectional area, orifice ovality index, and PV tilt angles. Results: The mean follow-up period was 14 months (12; 24). Long-term efficacy in the cryoablation group was 78.8% and in the RFA group—83.3% (OR = 0.74; 95% CI 0.41–1.3; p = 0.31). The RFA results did not depend on PV anatomy. The «difficult» occlusion of the right inferior PV (RIPV) occurred in 12 patients and was associated with a more horizontal PV position in the frontal plane; the mean tilt angle was −15.2 ± 6.2° versus −26.5 ± 6.3° in the absence of technical difficulties (p = 0.0001). In 11 cases (9%), during ablation of the right superior PV (RSPV), phrenic nerve injury (PNI) occurred and was associated with the maximum and minimum RSPV diameter, 20.0–20.4 mm (OR = 13.2; 95% CI: 4.7–41.9, p < 0.05) and 17.5–20 mm (OR = 12.5; 95% CI 3.4–51, p < 0.05), respectively. Patients with arrhythmia recurrence were characterized by significantly larger diameters and ovality of the left superior PV (LSPV). The spatial orientation of the PV does not affect the long-term results of cryoablation. Conclusion: Preprocedural evaluation of PV morphology and orientation using cardiac CT might help choose the optimal technology for the individual patient.

Aim. To estimate the efficacy of pulmonary veins (PV) cryoballoon isolation in its different anatomical variants.Methods. 230 patients 57 (53; 62) years of age were enrolled in the study in approximately equal proportion of males and females. Up to 1/3 of patients suffered from isolated AF, most of them belonged to the category of high risk of thromboembolic complications. To evaluate the PV anatomical variant, a modified classification of E. Marom et al was used. In groups of cryoballoon and radio-frequency isolation, subgroups of typical and variant anatomy were distinguished. Evaluation of the effectiveness of the intervention was based on the identification of any (symptomatic and asymptomatic) documented episodes of atrial arrhythmias lasting more than 30 seconds during the observation period of 12 months.Results. Comparison of efficacy in typical PV anatomy did not reveal significant differences between cryo and RFA groups, regardless of the type of device used. Subgroup I of generation of cryoballoons showed freedom from AF 83.2%, II generation – 87.5%, RFA group – 82.7% at p = 0.82. At the same time, with PV variant anatomy, the efficiency of cryo isolation with the use of II generation devices was 52.2 versus 85.7% in the RFA group (OR = 0.25; 95% CI 0.09–0.71; p = 0, 02). When analyzing long-term results in cryo and RFA groups depending on the anatomical variant, it was found that with RFA, the presence of a left PV common trunk (collector / vestibule), as well as the presence of additional veins, showed results comparable with the group of typical anatomy. At the same time, in the cryoablation group, the presence of a left common trunk was accompanied by a decrease in efficiency to 23.1 versus 84.9% for typical anatomy (OR = 0.14; 95% CI 0.03–0.6; p = 0.02) and 90% in the presence of additional veins (OR = 0.1; 95% CI 0.01–0.64; p = 0.02). In the presence of a left common trunk, the efficiency of cryoablation using second-generation cylinders was 23.1 versus 82.4% in the RFA group (OR = 0.16; 95% CI 0.05–0.5).Conclusion. The presence of a left PV common trunk leads to a decrease in the effectiveness of cryoablation in the long-term observation period relative to the group of typical anatomy to 23.1 versus 84.9% (OR = 0.14; 95% CI 0.03–0.6) and 82.4% for radiofrequency ablation (OR = 0.16; 95% CI 0.05–0.5). The presence of additional veins of right-sided localization does not affect the effectiveness of the intervention.

омплексные проблемы сердечно-сосудистых заболеваний К Основные положения • В статье представлен обзор современной литературы и систематизирована информация о механической функции левого предсердия, процессах ее ремоделирования после процедуры ан-тральной изоляции легочных вен, клинических проявлениях и прогностическом значении данного явления. РезюмеВ статье изложены современные представления о механической функции ле-вого предсердия (ЛП), ее компонентах и механизмах ремоделирования после процедуры антральной изоляции легочных вен. ЛП -это сердечная камера, которая выполняет не только транспортную функцию, но, являясь «органом» сложным как в анатомическом, так и в функциональном плане, активно реа-гирует на изменение гемодинамических условий, влияние гуморальных и ве-гетативных факторов. Структурное, механическое и электрическое ремодели-рование ЛП играют большую роль в аритмогенезе фибрилляции предсердий, а также в механизме поддержания аритмии. Механическая дисфункция ЛП, развивающаяся после катетерной аблации фибрилляции предсердий, оказыва-ет существенное влияние на внутрисердечную гемодинамику, ухудшает само-чувствие пациентов, а также увеличивает риск тромбоэмболических ослож-нений как в ближайшем, так и в отдаленном послеоперационном периодах. Ключевые словаФибрилляция Highlights • The article presents an overview of current evidence with a focus on the left atrial mechanical function, its remodeling after pulmonary vein antrum isolation, clinical manifestations and its prognostic significance. AbstractThe article presents new insights into the left atrial mechanical function, its main components and remodeling mechanisms after pulmonary vein antrum isolation. Left atrium is a cardiac chamber that transports blood. Being a complex «organ» both in anatomical and functional terms, it responds to hemodynamic derangements, the impact of humoral and vegetative factors. Structural, mechanical and electrical remodeling of the left atrium play a key role in the arrhythmogenesis of atrial fibrillation, as well as in the mechanism of arrhythmia maintenance. Left atrial mechanical dysfunction following catheter ablation of atrial fibrillation significantly affects intracardiac hemodynamics, worsens patients' well-being, and increases the risk of thromboembolic complications both in the immediate and long-term postoperative period. 137АНАЛИТИЧЕСКИЙ ОБЗОР REVIEWS