To evaluate the left ventricular function and mechanical dispersion (MD) by two-dimensional speckle tracking echocardiography (2D-STE) in patients with paroxysmal atrial fibrillation (PAF).

Thirty-seven patients with PAF and 29 controls were selected at the Department of Cardiology of Beijing Chaoyang Hospital Affiliated to Capital Medical University. All subjects underwent transthoracic echocardiography, and two-dimensional ultrasound parameters were routinely measured. Dynamic images of left ventricular apical four-chamber, two-chamber, and three-chamber views were collected as well. EchoPAC 203 software was used to measure the left ventricular myocardium global longitudinal strain (GLS) and longitudinal strain of each segment, and the MD was expressed by the standard deviation of the peak time of each segment. The differences in each parameter between the two groups were analyzed statistically.

Left atrial diameter (LAD), left atrial volume index (LAVI), left ventricular end-diastolic diameter (LVDd), left ventricular end-systolic diameter (LVSd), inter-ventricular septal thickness (IVST), and left ventricular posterior wall thickness (LVPWT) were larger, and left ventricular ejection fraction (LVEF) [(59.3±4.7)% vs (63.3±4.0)%] was less in the PAF group than in the control group (P＜0.05 for all). There was no significant difference in the ratio of mitral peak velocity to mitral annulus peak velocity (E/e') between the two groups (P＞0.05).Compared with the controls, the absolute value of GLS was decreased [(-17.9±2.3)% vs (-20.7±1.7)%] and MD was increased [(59.3±19.6) ms vs (43.0±10.2) ms] in PAF patients. In addition, PAF patients with a normal LA size exhibited significantly lower GLS and increased MD compared with controls (P＜0.05).

2D-STE can provide valuable information for the evaluation of early impaired left ventricular systolic function in PAF patients, thus providing a reliable basis for early intervention and clinical strategies for them.