Altered cardiac histology following apical right ventricular pacing in patients with congenital atrioventricular block
Altered cardiac histology following apical right ventricular pacing in patients with congenital atrioventricular block
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DOI：
10.1111/j.1540-8159.1999.tb00631.x
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发表时间：
1999-09-01
影响因子：
1.8
通讯作者：
Haas, JE
中科院分区：
文献类型：
--
作者：
Karpawich, PP;Rabah, R;Haas, JE
先前的研究表明，右室心尖部起搏固有地改变了心室收缩、局部血流、室壁应力，并易导致功能减退。然而，慢性心尖起搏可能导致所观察到的心功能不全的组织学后果仍然是推测的。以前的犬类研究已经证实，顶端启动的心室起搏会导致观察到的心功能减弱，从而导致组织病理学细胞异常。为了确定类似的不良变化是否也发生在临床环境中，从14例年龄匹配的先天性完全性房室传导阻滞(CCAVB)和其他解剖正常的患者中获得16例心内膜心肌活检，分为两组：8例来自起搏器植入前的患者(中位年龄15.5岁)，另8例来自植入起搏器前的患者(中位年龄16岁)，另8例来自3~12个PEAR(中位5.5岁)的慢性心室起搏患者。在一名患者中，在起搏前和起搏后分别采集了活检样本。结果显示，起搏后患者活检标本中的组织病理学改变显著增加(P<；0.05)，包括肌纤维大小变化、纤维化、脂肪沉积、硬化和线粒体形态变化。这些发现表明，慢性心尖右室起搏可能会在细胞和亚细胞水平上对心肌细胞的生长产生不利影响，特别是在年轻人中，这可能导致临床观察到的功能减弱。
Previous studies have demonstrated that right ventricular apical pacing inherently alters ventricular contraction, regional blood flow, wall stress, and predisposes to diminished function. However, histological consequences of chronic apical pacing potentially contributing to the observed ventricular dysfunction remain conjectural. Previous canine studies have demonstrated histopathological cellular abnormalities with apically initiated ventricular pacing that map result in the observed diminished ventricular function. To determine if comparable adverse changes also occur in the clinical setting, 16 endomyocardial biopsies were obtained from 14 age-matched patients with congenital complete atrioventricular block (CCAVB) and otherwise normal anatomy, divided into two groups: eight biopsies (median patient age 15.5 years) from patients prior to pacemaker implant and another eight biopsies (median patient age 16 years) from patients following 3-12 pears (median 5.5) of chronic ventricular pacing. In one patient, biopsy samples were obtained before and after pacing. Results demonstrated a significant (P < 0.05) increase in histopathological alterations among the patient biopsy samples following pacing, consisting of myofiber size variation, fibrosis, fat deposition, sclerosis, and mitochondrial morphological changes. These findings indicate that chronic apical right heart ventricular pacing may adversely alter myocellular growth, epecially among the young, on the cellular and subcellular level, potentially contributing to the diminished function observed clincially.