Radiofrequency ablation for the treatment of atrial fibrillation (AF) has recently been
performed under general anesthesia with patients connected to a mechanical ventilator
device. There are studies showing that whether patients are connected to spontaneous or
controlled ventilation directly affects the results of the ablation procedure. In the
ablation procedure, safe myocardial tissue contact of the catheter electrode determines
predictable lesion size distribution and ultimately procedural success. Therefore,
contact force has been a reliable marker in predicting the ability to deliver an
effective transmural lesion. Catheter tip movement due to respiratory changes may lead to
inadequate lesion formation, potentially resulting in AF recurrence. In the existing
literature, high-frequency jet ventilation (HFJV) has been reported to increase catheter
stability, improve tissue contact and reduce AF recurrence due to reduced thoracic
motion. An alternative strategy was used by simulating very low tidal volume ventilation
with high respiratory rate with a flow similar to HFJV with standard anesthesia devices.
The incidence of atrial fibrillation recurrence following catheter ablation depends on
various patient-level factors and procedural techniques. An important determinant of
success in AF ablation is the adequacy of the energy delivered to the cardiac tissue and
the durability of pulmonary vein isolation (PVI). Approximately 20% of patients
undergoing AF ablation require re-ablation within 12 months, regardless of technique. AF
recurrence following ablation occurs mainly through pulmonary vein electrical
reconnection, and the rate of ≥ 1 reconnected pulmonary vein during AF reablation is
>80%. Inadequate energy delivery and tissue heating due to insufficient contact or
challenging anatomical locations during ablation is one of the main culprits of procedure
failure in radiofrequency ablation (RFA). Therefore, efforts to improve the success of
the PVI procedure include optimizing catheter stability and contact force. Thus, catheter
force and stability are highly influenced by respiratory-induced thoracic movement,
demonstrating the importance of controlled breathing for further ablation optimization.
Fluoroscopy and ablation times during electroanatomic mapping-guided AF ablations have
improved significantly with the use of controlled mechanical ventilation. To improve
catheter contact, general anesthesia with controlled breathing has been used for better
procedural success than conscious sedation.
To date, there are no randomized clinical trials in the literature demonstrating the
superiority of one mode of ventilation over another during the ablation procedure. Low
tidal volume, high respiratory rate (FCV, Flow Controlled Ventilation), pressure
controlled mechanical ventilation (PCV), volume controlled mechanical ventilation (VCV),
pressure controlled volume guaranteed mechanical ventilation (PRVC) can be applied with
the mechanical ventilator equipment available in the anesthesiology and reanimation
clinic of investigators' hospital. However, HFJV mechanical ventilator mode cannot be
applied in general anesthesia patients in accordance with the facilities of
investigators' hospital. In addition, there is no definite information in the literature
about the superiority of any mode over the other for ablation procedure. Therefore,
different mechanical ventilation modes are applied in ablation procedures in
investigators' hospital according to the preferences of the practitioner. Investigators
believe that there is a need for studies on the modes used in ablation procedures
performed under general anesthesia.