Left atrial functional changes and its predictive value in the early period after cryoballoon ablation for paroxysmal atrial fibrillation

Abstract Introduction/Purpose In patients with paroxysmal atrial fibrillation (PAF), functional changes are observed in the left atrium (LA) after the pulmonary vein isolation (PVI) procedure. Although previous studies have investigated the altered mechanical functions of the LA with radiofrequency (RF) ablation, changes in the LA functions in the early period after cryoablation (CB-2) and the relationship between early period serial echocardiographic follow-ups after cryoablation and recurrence of atrial fibrillation/atrial tachycardia (AF/AT) have not been clearly demonstrated. This study aims to determine changes in the mechanical functions of LA in patients with PAF during the early period after cryoablation and whether these changes are effective in predicting the risk of recurrence by using echocardiographic parameters including Doppler and strain parameters. Methods Consecutive seventy-seven patients (mean age: 57.5±11.2 years; 57% men) with PAF underwent CB-2 and were prospectively analyzed. All patients were in sinus rhythm before and after the procedure. The LA dimensions, the LA reservoir strain (LASr), the LA atrial contractile strain (LASct), the LA conduit strain (LAScd) and left ventricular diastolic function parameters were evaluated by Doppler echocardiography before and 3 months after the procedure. Patients were monitored with 48-hour Holter at 1-3-6-12th months after the procedure to evaluate for recurrence. Results Acute procedural success was achieved in all cases. No major complications were observed. LASr and LASct showed significant recovery after the procedure (28.3±12.8% vs 34.6±13.8%, p<0.001 and -10.8±7.9% vs -13.9±9.3%, p=0.014 respectively). No significant change was demonstrated in other echocardiographic parameters. During the one-year follow-up after the procedure late recurrence (>3 months) of AF/AT was observed in 9 (11.7%) patients. Although the power of echocardiographic parameters in predicting recurrence was found to be not statistically significant, a downward trend especially in the values of LASr (p=0.068) and LASct (p=0.058) was observed at the 3rd month control echocardiographic results in patients with recurrence. Conclusion Significant improvement in mechanical functions may occur even in the early period after cryoballoon ablation in patients with PAF. In addition, as our study points out strain parameters, indicators of mechanical function tend to decline in patients with late term recurrence.