The evaluation of relationship among acute process success and late recurrence with heat-term parameters in patients with acute atrial fibrilation who underwent ablation

Background and Aims: Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice and it is associated with an increased risk of mortality and morbidity. The maintenance of sinus rhythm in patients with AF is associated with improved quality of life and decreased symptoms. AF catheter ablation has become an alternative to antiarrhythmic therapy for maintenance of sinus rhythm. As an alternative to the radiofrequency ablation cryoablation method has found widespread application area. Various technical parameters were studied in order to evaluate the acute procedural success of cryoablation. One of these are the thermal parameters . The aim of ourstudy is to evaluate the acute procedural success of this method and to assess the realtionship between late clinical recurrence and time – temperature parameters. Method: In our study 102 patients undergoing atrial fibrillation (AF) ablation with cryoablation method between January 2011 and May 2014 were included. All data were analyzed retrospectively. Time-temperature parameters of this method were obtained by investigating the data of cryoconsole cardiac ablation system (Medtronic CryoCath LP ) . Nadir temperature; the minimum temperature reached during the procedure, nadir temperature time ; time to reach minimum temperature, freezing time ; time between the closing of the balloon cover and the beginning of slow cooling phase , freezing degree; temperature at freezing time. Warming time ; time up to 20 degrees from the start , and time to reach the threshold temperature was defined as the time to reach -42 c for superior veins and -39 c for inferior veins. The relationship between acute reconnection and late clinical recurrence of these parameters was evaluated. Results: From a total of 408 Pulmonary vein (PV), 367 vein (89%) underwent cryoablation. In the control performed thirty minute after the procedure signal was detected again in 12 veins (3.2%). These veins, which are characterized in acute reconnection in terms of thermal parameters were compared with those are not. In the grup with acute recurrence, nadir temperature was found significantly higher (-40,5 ± 5,5 ºc versus -49 ± 6,8 ºc p < 0,001). Time to reach maximum temperature was found significantly longer (182,1 ± 35,7 sec versus 148,8 ± 27,4 ºc p = 0,001), freezing time was found significantly longer (31,6 ± 4,5 sec versus 26,5 ± 3,7) freezing degree was found significantly higher (-21,4 ± 2,7 ºc versus -26,5 ± 4,8 ºc P < 0,001), warming time was found significantly shorter (24 ± 4 sec versus 84,7 ± 22,8 ºc p < 0,001), time to reach the threshold temperature was found significantly longer (90,5 ± 45,1 sec versus 70,3 ± 41,5 sec p = 0,02). In 33 (% 32.4) of the 102 included patients late recurrence was determined. Thermal parameters were evaluated in terms of its relationship with late recurrence . There was no significant difference between the late recurrence and nadir temperature, time to reach nadir temperature, freezing time, freezing degree, warming time and time to reach the threshold temperature. Conclusıon: Temperature-time parameters are associated with acute reconnection and procedure success in pulmonary vein isolation performed using cryoablation in patients with atrial fibrillation .Our study demonstrates that time-temperature parameters are not associated with late recurrence . But, it can be used as a predictors of acute relapses.