Introduction: Previous studies have shown, that left atrial (LA) fibrosis could be identified not only by MRI investigation, but voltage mapping during ablation procedure. The aim of this study is to evaluate the fibrosis intensity and to сompare it with the duration of history of atrial fibrillation and clinical outcome of AF-ablation.
Methods: Patients underwent voltage mapping during the AF-ablation procedure. The LA mapping was performed using Ensite Velocity navigation system (St.Jude Madical, US). The LA geometry was collected by using the 20-pole lasso catheter (Biosense Webster, US). Peak-to-peak voltages have been collected from the 10 bipoles of the circular mapping catheter. The ablation procedure was performed using Blazer Open Irrigated catheters (Boston Scientific, US) and 10F AcuNav ICE-catheters (Siemens). Special software was created to assess the severity of fibrosis as well as to derive the digital index - the index of LA-fibosis (IF).
Results: We enrolled 44 patients. Mean follow-up was 5.8 months with total efficacy of single procedure 72.7%. We performed voltage mapping and PVI in all cases. All the IF value varied from 0.33 up to 6.89. We observed strong correlation between IF and AF longevity (p= 0.0315), but no evident dependence with LA-volume. Also we revealed the relationship between AF-reccurrence rate and IF (p= 0.07). Maximum IF-value (6.89) corresponds with sick sinus syndrome with indications to pacemaker implantation.
Conclusion: Intraoperative voltage mapping is useful in evaluation of LA fibrosis index. There is strong correlation between IF and AF longevity and relationship of IF with AF recurrence. This method may be effective in estimating of PVI efficacy on mid-term period of follow-up.