Effects of Metoprolo and Diltiazem on P Wave Dispersion in Patients with Mitral Stenosis

OBJECTIVE
In mitral stenosis. higher P wave dispersion has been shown to exist due to atrial dilatation and sympathetic overactivity because of reduced cardiac output. P wave dispersion is also closely related to atrial fibrillation. Our aim was to evaluate the effects of metoprolol and diltiazem on P wave dispersion (PWD), and on maximum and minimum P wave duration in patients with mitral stenosis (MS).
METHODS
All patients with MS in sinus rhythm were randomized into two groups, one of which was composed of 44 patients (36 women, aged 36±12 years) treated with metoprolol, and the other composed of 40 patients (35 women, aged 40 ±9 years) treated with diltiazem. Left atrial and left ventricular diameters, mean and peak transmitral gradientsdnitral valve area, and left ventricular ejection fractions were measured by transthoracic echocardiographic examination. Before and one month after treatment, P wave durations were measured manually under magnifying glass in twelve -lead ECG.
RESULTS
No significant difference was recorded between group I and group II in terms of baseline echocardiographic values. maximum P wave duration. minimum P wave duration. and PWD. In the metoprolol-treatment-group. we observed that maximum P ware duration. mininuun P wave duration. PWD and mean transmitral gradient were significantly reduced (p<0.0I ). In the diltiazem-treatment-group. a significant decrease was detected in PWD. mean transmitral gradient and maximum P wave duration but not in minimum P wave duration (p>0.05). In the two groups, the significant decreases in maximtun P wave duration. PWD and mean transmitral gradient were more pronounced in the metoprolol-treatment-group (p<0.00/). There were no statistically significant differences between the other parameters.
CONCLUSION
Treatment with either diltiazem or metoprolol decreased in PWD and maximum P wave duration in patients with MS significantly, yet, this was more pronounced in the metoprolol-treatment-group