The acute effect of percutaneous mitral balloon valvuloplasty on atrial electromechanical delay and P-wave dispersion in patients with mitral stenosis.

Background And Aim Of The Study: The predisposition to atrial fibrillation (AF) in mitral stenosis (MS) has been demonstrated with several electrocardiographic (increased P-wave dispersion) and echocardiographic parameters (atrial electromechanical delay). Despite the improvement in P-wave dispersion after percutaneous mitral balloon valvuloplasty (PMBV), the changes in echocardiographic parameters related to AF risk are unknown. In this study we aimed to investigate the acute effect of PMBV on atrial electromechanical delay (EMD) assessed by tissue Doppler echocardiography in addition to electrocardiographic parameters.

Materials And Methods: This single-center study consisted of 30 patients with moderate or severe MS (23 females and seven males, aged 36.5 ± 8.5 years, with a mean MVA of 1.1 ± 0.2 cm) who underwent successful PMBV without complication at our clinic and 20 healthy volunteers from hospital staff as a control group (16 females and four males, aged 35.4 ± 6 years). We compared the two groups in regard to clinical, electrocardiographic and echocardiographic features. The patients with MS were also evaluated after PMBV within 72 h of the procedure. The P-wave dispersion was calculated from12-lead ECG. Interatrial and intra-atrial EMDs were measured by tissue Doppler echocardiography. These ECG and echocardiographic parameters after PMBV were compared with previous values.

Results: The maximum P-wave duration (138 ± 15 vs. 101 ± 6 ms, p < 0.01), PWD (58 ± 18 vs 23 ± 4, p < 0.01), the interatrial (55 ± 16 vs 36 ± 11 ms, p < 0.01) and left-sided intra-atrial EMD (40 ± 11 vs 24 ± 12 ms, p < 0.01) were higher in patients with MS than in healthy subjects. The left atrial (LA) diameter, LA volume and LA volume index had positive association with the interatrial (r = 0.5, p < 0.01; r = 0.5, p < 0.01 and r = 0.5, p < 0.01, respectively) and left-sided intra-atrial EMD (r = 0.5, p < 0.01; r = 0.4, p < 0.01; r = 0.4, p < 0.01 respectively). After PMBV, the interatrial (55 ± 16 vs. 40 ± 11 ms, p < 0.01) and left-sided intra-atrial EMD (40 ± 11 vs 31 ± 10, p < 0.01) showed significant improvement compared to previous values. There was also a statistically significant difference in maximum P-wave duration and PWD between pre-and post-PMBV (138 ± 15 vs 130 ± 14, p < 0.01, and 58 ± 18 vs 49 ± 16, p < 0.01, respectively).

Conclusions: Our study shows that PMBV has a favorable effect on the electrocardiographic and echocardiographic parameters related with AF risk in patients with MS.