Evaluation of Left Atrial Structure and Function with Two-dimensional Speckle Tracking Imaging and Real-time Three-dimensional Imaging in Patients with Paroxysmal Atrial Fibrillation After Radiofrequency Catheter Ablation

  Objective  To observe the changes of left atrial structure and function in patients with paroxysmal atrial fibrillation (PAF) after radiofrequency catheter ablation by two-dimensional speckle tracking imaging (STI) and real-time three-dimensional imaging technology (RT-3D) in order to provide basis for clinical evaluation of surgery.

  Methods  Thirty two (32) cases of PAF patients with catheter ablation from October 2016 to December 2017 in our hospital were enrolled. According to sinus rhythm whether or not be restored after operation, the patients were divided into sinus rhythm group (SR group, 24 cases) and atrial brillation group (AF group, 8 cases). All PAF patients received echocardiography before and 1, 6 months after surgery. Left atrial structure and functional parameters were measured by STI and RT-3D, including left atrial diameter, volume, left ventricular systole, early diastolic, left atrial systolic peak strain rate and ejection fraction.

  Results  All parameters in AF group were not changed significantly after surgery (P>0.05). In SR group, at 6 month after surgery, the levels of Left atrial anteroposterior diameter (LAAPD), Left atrial up and down diameter (LAUDD), Left atrial left and right diameter (LALRD), minimum volume of left atrium (LAV_min), Left atrial presystolic volume (LAV_p) and max volume of left atrium (LAV_max) were significantly decreased, the levels of Left atrial ejection fraction (LAEF), Left atrial active ejection fraction (LAAEF), Left atrial passive ejection fraction (LAPEF) were significantly increased, the strain rates (SRS, SRE, SRA) in the lateral wall base segment, interval middle segment and middle segment of the lateral wall and overall strain parameters (GLSR_S, GLSR_E, GLSR_A) were significantly increased (all P<0.05); and the other segment strain rates were not significantly changed (P>0.05). In AF group, at 6 month after surgery, the levels of LAV_min, LAV_p and LAV_max were significantly decreased at 6 month after operation, the levels of LAEF, LAAEF were significantly increased, all above had statistical difference (P<0.05); and the other parameters were not significantly changed (P>0.05).

  Conclusion  STI and RT-3D could quantitatively analyze the structure and function of left atrium before and after radiofrequency ablation in PAF patients. After ablation, the diameter of LA decreases and the ejection fraction increases in the patients with sinus rhythm; the volume of LA increases and the function reduces in the patients with atrial fibrillation recurrence.