Heart rate variability in patients after catheter-based radiofrequency pulmonary vein isolation

Abstract

The aim – to analyze the dynamics of heart rate variability in patients who underwent radiofrequency isolation of pulmonary veins using the «high power – short duration» technique, and to determine its relationship with the probability of arrhythmia recurrence in the postoperative period.
Materials and methods. To conduct a study of heart rate variability, a total of 114 patients with paroxysmal and persistent forms of atrial fibrillation (AF) were analyzed, who underwent catheter radiofrequency pulmonary vein isolation at the State Institution «National Institute of Cardiovascular Surgery named after M.M. Amosov of the National Academy of Medical Sciences of Ukraine» for the period from May 2022 to December 2024. 49 patients were selected for the study in whom long-term results regarding arrhythmia recurrence were monitored.
Results. The follow-up period of patients after pulmonary vein isolation (PVI) was on average 19.87±7.56 months (range 8 to 34 months). The frequency of arrhythmia recurrence during this period was 38 %. 26.4 % of patients were diagnosed with persistent atrial fibrillation (AF). At all time points, patients without recurrence had a higher mean heart rate, which may indicate a more effective denervation. The largest difference was observed after 2 months: in patients without recurrence 73.44±9.93 beats/min, with recurrence: 62.50±10.45 beats/min (p=0.01). After 1, 6, and 12 months, there was a trend towards a decrease in heart rate in the group of patients with arrhythmia recurrence, although it did not reach statistical significance (p>0.05). Patients with recurrence showed significantly higher RMSSD values, especially at 2 and 12 months. 2 months: 51.25±68.60 vs 19.00±11.59 (p=0.365); 12 months: 32.6±22.9 vs 15.43±6.00 (p=0.026). At 1 month, SDNN was significantly higher in patients with recurrence: 77.50±38.78 vs 53.51±20.86 (p=0.047). SDNNi is also higher in patients with relapse: 1 month – 44.13±25.31 vs 28.00±11.26 (p=0.021); 2 months: 55.0±38.4 vs 26.67±4.23 (p=0.002). This may be due to incomplete or transient modulation of ganglionic structures, which is manifested by a high SDNN. At later times (6–12 months), the differences smoothed out and statistical significance was not found. pNN50 is another marker of parasympathetic activity. Significant differences in pNN50 were found at 12 months: 8.95±9.92 (with relapse) vs 1.78±1.78 (without) (p=0.026). Paroxysmal AF was more common in the group without recurrence (86 % vs. 73 %), which was statistically significant (p=0.022). Also, the end-diastolic index (EDI) was significantly higher in the group without recurrence (66.02±9.78 vs. 59.56±4.05; p=0.023). The left atrial diameter tended to be larger in the group of patients with recurrence ((43.47±5.15) vs. (41.77±4.64) mm; p=0.091). Body mass index (BMI) tended to be higher in the group without recurrence (30.35±5.78 vs. 27.36±3.84; p=0.054), but the difference did not reach statistical significance.
Conclusions. Patients with signs of more pronounced intraoperative modification of parasympathetic ganglia functions during catheter radiofrequency isolation of the lungs with fewer arrhythmia recurrences during time control are observed in 19.87±7.56 months. Lower RMSSD values ​​in use without recurrence, especially in the early stages after ablation, as well as lower pNN50 values ​​after 12 months confirm a decrease in parasympathetic activity, compared with patients in whom arrhythmia recurrence occurred. Changes in HRV may be useful for assessing the effectiveness of concomitant cardioneuroablation during pulmonary vein isolation.