Ikeda T
Third Department of Internal Medicine, Toho University School of Medicine, Ohashi Hospital, Tokyo.
J Cardiol. 1991;21(3):717-26.
The frequency and significance of mitral valve prolapse (MVP) were assessed in 35 patients with idiopathic ventricular tachycardia (VT) (12 with sustained VT and 23 with nonsustained VT). They were classified as MVP and non-MVP groups according to their results of two-dimensional echocardiography. The frequency and characteristics of MVP in idiopathic VT, symptoms during VT, QRS configurations on electrocardiogram during VT, and induction of VT in electrophysiologic study were evaluated. MVP was recognized in 12 (34.3%) of 35 patients with idiopathic VT, all of whom had mild prolapse of the anterior leaflet. The frequency of MVP in patients with sustained VT was higher than that in patients with nonsustained VT (58.3% vs 21.7%, p < 0.05). Of all the symptoms during VT, palpitation was most frequently observed in the MVP group (66.7%), while no characteristic symptom was observed in the non-MVP group. This symptomatic difference was considered to be attributable to different patterns of VT duration. QRS configurations during VT showed monomorphism in all patients. The right bundle branch block pattern was dominant in the MVP group (91.7%), while the left bundle branch block pattern was prominent in the non-MVP group (69.6%) (p < 0.01), suggesting that VT mainly originated in the left ventricle in the MVP group and in the right ventricle in the non-MVP group. The induction rate of VT by programmed ventricular stimulation was higher in the MVP group (58.3%) than in the non-MVP group (34.8%) (p < 0.07) and was considerably higher in patients with sustained VT (75.0%) than in patients with nonsustained VT (26.1%) (p < 0.01). However, there was no significant difference in the induction rates between patients with sustained VT in the MVP and non-MVP groups. The difference in the VT induction rates between the 2 groups may be related to other factors besides the duration of VT. In conclusion, the incidence of MVP was relatively high in patients with idiopathic VT, and the difference of the clinical and electrophysiologic characteristics of idiopathic VT may depend on whether MVP is present or not.
在35例特发性室性心动过速（VT）患者（12例持续性室速和23例非持续性室速）中评估二尖瓣脱垂（MVP）的发生率及意义。根据二维超声心动图结果将患者分为MVP组和非MVP组。评估特发性室速中MVP的发生率及特征、室速发作时的症状、室速发作时心电图的QRS形态以及电生理研究中室速的诱发情况。35例特发性室速患者中有12例（34.3%）被诊断为MVP，所有患者均为前叶轻度脱垂。持续性室速患者中MVP的发生率高于非持续性室速患者（58.3%对21.7%，p<0.05）。在室速发作时的所有症状中，MVP组最常出现心悸（66.7%），而非MVP组未观察到特征性症状。这种症状差异被认为与室速持续时间的不同模式有关。室速发作时的QRS形态在所有患者中均为单形性。MVP组以右束支阻滞形态为主（91.7%），而非MVP组以左束支阻滞形态为主（69.6%）（p<0.01），提示MVP组室速主要起源于左心室，而非MVP组室速主要起源于右心室。MVP组通过程控心室刺激诱发室速的发生率高于非MVP组（58.3%对34.8%，p<0.07），持续性室速患者的诱发率显著高于非持续性室速患者（75.0%对26.1%，p<0.01）。然而，MVP组和非MVP组持续性室速患者的诱发率之间无显著差异。两组室速诱发率的差异可能与室速持续时间以外的其他因素有关。总之，特发性室速患者中MVP的发生率相对较高，特发性室速临床和电生理特征的差异可能取决于是否存在MVP。
