Evaluation of Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio in patients with mitral valve stenosis before and after balloon valvuloplasty.

Abstract

Objective:Sympathetic activity increases in patients with mitral stenosis (MS). The association between prolonged Tpeak-Tend (Tp-e) interval and increased sympathetic activity has been demonstrated. This study aimed to evaluate Tp-e interval, Tp-e/QT ratio, and Tp-e/corrected QT interval (QTc) ratio in patients with MS before and after balloon valvuloplasty.Methods:Thirty patients with severe MS and 30 sex-, body mass index-, and and age-matched healthy control subjects were enrolled. The severity of MS was defined following clinical, transthoracic, and transesophageal echocardiographic examinations. All patients underwent successful mitral balloon valvuloplasty. Tp-e interval, Tp-e/QT, and Tp-e/QTc ratios were measured using 12-lead electrocardiogram. First, the abovementioned parameters were compared between patients with MS and healthy control subjects. Second, these parameters were compared before and after balloon valvuloplasty in patients with MS.Results:The mean Tp-e interval was significantly prolonged in patients with MS compared with healthy control subjects (85.02±9.12 ms vs. 75.38±6.04 ms; p<0.001). In addition, Tp-e/QT ratio and Tp-e/QTc ratio were significantly higher in patients with MS than in healthy control subjects (0.217±0.025 vs. 0.196±0.02 and 0.203±0.02 vs. 0.184±0.019; p<0.001).The mean valve area significantly increased after balloon valvuloplasty compared with that before balloon valvuloplasty (1.83±0.32 cm2 vs. 1.18±0.15 cm2; p<0.001). Compared with those before balloon valvuloplasty, Tp-e interval (85.02±9.12 ms vs. 78.06±9.2 ms; p<0.001), Tp-e/QT ratio (0.217±0.02 vs. 0.201±0.02; p<0.001), and Tp-e/QTc ratio (0.203±0.02 vs. 0.184±0.02; p<0.001) decreased after balloon valvuloplasty.Conclusion:We revealed that Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio increased in patients with severe MS. Furthermore, balloon valvuloplasty had a favorable effect on parameters associated with myocardial repolarization.