Mitral annular velocity in patients with postoperative atrial fibrillation.

BACKGROUND

Subclinical atrial stunning (AS) (left atrial dysfunction) may increase vulnerability to oxidative and inflammatory stressors, thus increasing the likelihood of postoperative supraventricular arrhythmias, especially atrial fibrillation (AF). Evaluation of mitral annular velocities by tissue Doppler imaging (TDI) may be useful in seeking subclinical AS. This prospective study aimed to evaluate the relationship between atrial fibrillation after bypass surgery and presurgical determination of subclinical AS by assessing mitral annular velocities by TDI.

METHODS

We enrolled patients who underwent coronary artery bypass graft (CABG) surgery into this prospective study. Inclusion criteria were sinus rhythm and a negative history of atrial tachycardia during the previous 3 mo. An experienced cardiologist performed transthoracic echocardiography in all patients. We recorded standard two-dimensional, mitral inflow conventional Doppler interrogation and TDI pulsed wave data from the lateral and septal annulus. All patients underwent CABG surgery at our Cardiovascular Surgery Unit. Patients were divided into two groups based on their postoperative AF status: group 1 patients had postoperative AF and group 2 patients did not.

RESULTS

This study included 44 patients. Age and the presence of chronic obstructive pulmonary disease were the only two significantly different parameters among clinical characteristics between groups. Echocardiographic findings that were statistically significantly different between groups were as follows: lateral A diastolic mitral annular velocity, group 1: 0.11 ± 0.19 ms(-1)versus group 2: 0.08 ± 0.19 ms(-1) (P = 0.001); lateral E diastolic mitral annular velocity, group 1: 0.69 ± 0.24 ms(-1)versus group 2: 0.62 ± 0.31 ms(-1) (P = 0.016); Septal E diastolic mitral annular velocity, group 1: 0.05 ± 0.01 ms(-1)versus group 2: 0.04 ± 0.01 ms(-1) (P = 0.033); septal A diastolic mitral annular velocity, group 1: 0.08 ± 0.02 ms(-1)versus group 2: 0.05 ± 0.02 ms(-1) (P = 0.005).

CONCLUSIONS

There is no relationship between AF after CABG surgery and preexisting subclinical AS determined with mitral annular velocities by TDI. Preoperative appropriate prophylactic treatment should be administered to all patients.