Takamoto T, Nitta M, Taniguchi K
2nd Department of Internal Medicine, Faculty of Medicine, Tokyo Medical and Dental University.
Bull Tokyo Med Dent Univ. 1987 Sep;34(3):61-8.
To investigate the apparent association of mitral anular calcification (MAC) and electrocardiographic abnormalities, the relation between the location of two-dimensional (2D) echoquantified MAC and conduction disturbances was studied in 140 patients with MAC (MAC group) and 135 age- and sex-matched patients without MAC (control group). The MAC group was subclassified regarding the site and severity of calcium in the mitral anulus. The site of MAC was defined as Type I of MAC near the conduction system and Type II of MAC away from the conduction system. The severity of MAC was graded on 2D echocardiography as mild (localized within 1 segment) and moderate to severe (more than 1 segment). Seven patients with MAC, and only one control subject, had pacemakers in place. Conduction disturbances were present in 44 (31%) of 140 patients with MAC and in 37 (27%) of the 135 control patients (no significant difference). But there were more conduction disturbances in the patients with Type 1 MAC (53%) than in those with Type II MAC (26%) (p less than 0.01). Specifically, complete left bundle branch block and intraventricular conduction delay were more prevalent when MAC was near the conduction system. Intraventricular conduction delay also was more prevalent in the patients with Type I MAC than in the control group (Type I: 12% vs control: 4%; p less than 0.05). These data suggest that moderate to severe degrees of MAC located near the conduction system are associated with conduction disturbances, especially intraventricular conduction delay.
为研究二尖瓣环钙化（MAC）与心电图异常之间的明显关联，我们在140例MAC患者（MAC组）和135例年龄及性别匹配的无MAC患者（对照组）中，研究了二维（2D）超声心动图量化的MAC位置与传导障碍之间的关系。MAC组根据二尖瓣环钙化的部位和严重程度进行亚分类。MAC的部位被定义为靠近传导系统的I型MAC和远离传导系统的II型MAC。MAC的严重程度在二维超声心动图上分为轻度（局限于1个节段内）和中度至重度（超过1个节段）。MAC组中有7例患者和对照组中仅有1例患者植入了起搏器。140例MAC患者中有44例（31%）存在传导障碍，135例对照患者中有37例（27%）存在传导障碍（无显著差异）。但I型MAC患者的传导障碍（53%）比II型MAC患者（26%）更多（p<0.01）。具体而言，当MAC靠近传导系统时，完全性左束支传导阻滞和室内传导延迟更为常见。I型MAC患者的室内传导延迟也比对照组更常见（I型：12% vs对照组：4%；p<0.05）。这些数据表明，位于传导系统附近的中度至重度MAC与传导障碍相关，尤其是室内传导延迟。
