Vol 3, No 2 (2023)

BACKGROUND: Thoracoscopic version of the MAZE operation alone or in combination with catheter ablation (hybrid approach) has become widespread in the treatment of atrial fibrillation (AFib). However, recurrences of arrhythmias after such operations, in particular recurrence of AFib, remain unresolved problem.

AIM: The aim of this study was to establish the structure of arrhythmia recurrence in patients with long-standing persistent AFib after primary epicardial ablation using the Dallas lesion set technique, as well as determining the optimal RFA strategy for recurrence.

METHODS: 138 catheter ablation procedures for 100 patients, who applied with recurrence of various atrial arrhythmias after thoracoscopic MAZE. 34 patients had 2 or more RFA (31 pts — 2, 2 pts — 3, 1 pts — 4).

RESULTS: After Dallas lesion set thoracoscopic ablation in the structure of recurrences dominated: 1 — AFib recurence; 2 — incisional left atrial flutter. After the operation, a potential arrhythmogenic substrate remains, which must be fully eliminated by RFA (in addition to ablation the main cause of recurrence). This minimally necessary intervention implies: control and reisolation of the pulmonary veins; control and reisolation of the posterior wall; septal line from the mitral valve to the right superior pulmonary vein with Y-shaped branch to the left superior pulmonary vein; cava-tricuspid isthmus-blockade. This will eliminate and prevent in the future potentially possible incisional arrhythmias in fragmentary scars after thoracoscopic MAZE procedure. The return of AFib represents the most difficult group of patients. Restoration of sinus rhythm in recurrent AFib after epicardial ablation is possible, but may require extensive ablations in both atriums, as a result of repeated procedures, until all potential arrhythmia mechanisms, present in a particular patient, are eliminated.

CONCLUSIONS: Catheter ablation remains the only method of effective treatment of recurrences after thoracoscopic MAZE procedure. The complexity and multicomponent nature of long-standing AFib causes the frequent need for repeated procedures, especially in cases of recurrence of atrial fibrillation.

The review article presents dates about the physiology and pathophysiology of the hemostasis system, discusses the features of the use of oral anticoagulants in clinical practice. Oral anticoagulants are drugs characterized by predictable pharmacokinetics and pharmacodynamics, a favorable efficacy and safety profile. The article considers the main clinical and pharmacological characteristics of apixaban, rivaroxaban and dabigatran (bioavailability, metabolism, excretion); factors that increase the risk of gastrointestinal bleeding associated with anticoagulant therapy; drug interactions; the possibility of gastroprotection in patients taking oral anticoagulants. In real clinical practice, the reason for not prescribing or unreasonably reducing the dose of oral anticoagulants is the fear of bleeding. In this case, the risks of bleeding, as a rule, are overestimated. Knowledge of bleeding risk factors, prognostic scales and management of risk factors is an approach that can improve the safety of anticoagulant therapy. In clinical practice, the choice of the ideal oral anticoagulants, in addition to taking into account the risk of bleeding, should be based on a comprehensive assessment, including an assessment of the patient's age, risk of stroke and coronary events, renal function, and predicted compliance.