Changes in P-wave after percutaneous mitral valvuloplasty in patients with mitral stenosis and left atrial enlargement.

OBJECTIVE To investigate potential clinical, echocardiographic and/or hemodynamic predictors of the regression of electrocardiographic (ECG) signs of left atrial enlargement (LAE) after successful percutaneous mitral valvuloplasty (PMV). METHODS We studied 24 patients (75% female, mean age =37.1 +/- 11.9 years) with moderate to severe mitral stenosis (MS), sinus rhythm (SR) and ECG signs of LAE who underwent successful PMV between 2002 and 2004. At least 6 months after the procedure (388.2 +/- 192.9 days), the patients returned for clinical, ECG and echocardiographic follow-up. They were then divided in 2 groups: patients of group 1 (n = 8; 33.3%) still had ECG signs of LAE, and patients of group 2 (n = 16; 66.6%), had normal P wave. A multivariate analysis of clinical, ECG, echocardiographic and hemodynamic variables was performed. RESULTS The mitral valve area (MVA) increased from 1.12 +/- 0.15 cm2 to 1.9 +/- 0.35 cm2 immediately after the procedure (p < 0.0001) and decreased to 1.89 +/- 0.41 cm2 at follow-up (p = NS). Left atrium diameter decreased from 48 +/- 2.9 mm pre-procedure to 43 +/- 4.8 mm at follow-up (p = 0.0001). P-wave duration decreased from 0.12 +/- 0.01 sec pre-PMV to 0.09 +/- 0.02 sec at follow-up (p = 0.0001). An MVA > or = 1.7 cm2 at follow-up was the only independent predictor of a normal P-wave after PMV (p=0.02). CONCLUSION ECG changes suggestive of LAE regress in the majority of patients with MS and sinus rhythm that undergo a successful PMV. An MVA > or = 1.7 cm2 at late follow-up was found to be an independent predictor of such normalization.