Abstract 2078: Interatrial Dyssynchrony Determined by Tissue Doppler Imaging Predict the Transition to Chronic Atrial Fibrillation in Patients With Nonvalvular Paroxysmal Atrial Fibrillation
Aims: It is well known that paroxysmal atrial fibrillation (PAF) often precedes the establishment of chronic AF (CAF). However, it remains difficult to predict the transition from PAF to CAF. The purpose of this study was to determine prospectively whether interatrial dyssynchrony determined by tissue Doppler imaging (TDI) is useful for the prediction of the transition to CAF in patients with nonvalvular PAF.
Methods: To evaluate the ability to predict the transition to CAF, 37 consecutive patients with nonvalvular PAF (19 males) were prospectively followed after transthoracic echocardiography with TDI. We measured the interval of time from initiation of the ECG P wave until the peak of the atrial systolic TDI signal at the lateral areas of the mitral (P-A′ (M)) and tricuspid (P-A′ (T)) annulus. Interatrial dyssynchrony was defined as the prolongation of the difference between the time of P-A′ (M) and P-A′ (T) interval (A′ (M)-A′ (T)). The study endpoint was the transition to CAF (persistent or permanent AF; > 6 months) during the follow-up period.
Results: During a follow-up of 28 ± 23 months, 8 patients acquired CAF. In our relative elderly patients (mean age: 71 ± 11 years), patients with CAF, compared with those without, showed significantly lower peak A velocity (57 ± 19 vs 75 ± 18 cm/sec, p = 0.02) and higher peak E/A velocity ratio (1.41 ± 0.49 vs 0.92 ± 0.26, p = 0.0007) of transmitral inflow, and lower peak atrial systolic mitral annular tissue Doppler velocity (A′ (M)) (7.7 ± 1.7 vs 10.7 ± 2.9 cm/sec, p = 0.006), and longer A′ (M)-A′ (T) interval (47 ± 13 vs 24 ± 10 msec, p = 0.0001). No significant differences were found with respect to other parameters. Kaplan-Meier analysis revealed that the transition to CAF was significantly observed more often when A′ (M)-A′ (T) interval ≥ 30 msec (mean value) (p = 0.003), and A′ (M) velocity ≤ 10 cm/sec (p = 0.01).
Conclusions: This prospective study suggests that (i) nonvalvular PAF patients at high risk for the transition to CAF seem to have “interatrial dyssynchrony” and “atrial systolic dysfunction” pattern of atrial TDI, and that (ii) transthoracic echocardiography with TDI could be useful to identify patients at high risk for the transition from nonvalvular PAF to CAF, and could be attractive because of the ease of acquiring the data.