Mizobuchi Aya, Maruhashi Tatsuya, Saito Yusuke, Yamaji Takayuki, Harada Takahiro, Yusoff Farina Mohamad, Kishimoto Shinji, Kajikawa Masato, Nakashima Ayumu, Higashi Yukihito
Department of Regeneration and Medicine, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan.
Center for Radiation Disaster Medical Science, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan.
Sci Rep. 2024 Dec 5;14(1):30315. doi: 10.1038/s41598-024-81211-6.
First-degree atrioventricular block (AVB) is a common electrocardiogram finding in clinical practice. Vascular dysfunction is associated with cardiovascular disease and events. There is no information on the association of AVB with vascular function. The purpose of this study was to evaluate the associations of PR interval with vascular function assessed in well-characterized subjects. A total of 2220 subjects were enrolled in this study. We evaluated endothelium-dependent vasodilatation assessed by flow-mediated vasodilation (FMD) and endothelium-independent vasodilatation assessed by nitroglycerine-induced vasodilation (NID) in 106 subjects with first-degree AVB (70 men; mean age, 64.3 ± 12.9 years) and 1241 subjects with normal PR interval (531 men; mean age, 56.1 ± 13.9 years). Subjects with first-degree AVB had a lower FMD value than that in subjects with normal PR interval (3.5 ± 2.4% vs. 4.9 ± 3.3%, P < 0.001). FMD was significantly lower in subjects with first-degree AVB than in subjects with normal PR interval even after adjustment of confounding factors for assessment of endothelium-dependent vasodilatation (OR: 1.73, 95% CI: 1.11-2.70; P = 0.015). Although NID was significantly lower in subjects with first-degree AVB than in subjects with normal PR interval (11.1 ± 6.0% vs. 13.6 ± 6.1%, P < 0.001), there was no significant difference in NID between the two groups in multivariate analysis (OR: 1.48, 95% CI: 0.91-2.41; P = 0.117). Both endothelium-dependent and endothelium-independent vasodilation in the brachial artery are impaired in parallel with the prolongation of atrioventricular conduction. After adjustments of confounding factors for vascular function, first-degree AVB is associated with impaired endothelium-dependent vasodilatation but not with impaired endothelium-independent vasodilatation. From the aspect of vascular function, it is unlikely that first-degree AVB is an electrocardiography abnormality with a good prognosis.
一度房室传导阻滞（AVB）是临床实践中常见的心电图表现。血管功能障碍与心血管疾病及事件相关。目前尚无关于AVB与血管功能关联的信息。本研究的目的是评估PR间期与在特征明确的受试者中评估的血管功能之间的关联。本研究共纳入2220名受试者。我们在106例一度AVB患者（70例男性；平均年龄64.3±12.9岁）和1241例PR间期正常的受试者（531例男性；平均年龄56.1±13.9岁）中评估了通过血流介导的血管舒张（FMD）评估的内皮依赖性血管舒张和通过硝酸甘油诱导的血管舒张（NID）评估的非内皮依赖性血管舒张。一度AVB患者的FMD值低于PR间期正常的受试者（3.5±2.4%对4.9±3.3%，P<0.001）。即使在调整了用于评估内皮依赖性血管舒张的混杂因素后，一度AVB患者的FMD仍显著低于PR间期正常的受试者（OR：1.73，95%CI：1.11 - 2.70；P = 0.015）。虽然一度AVB患者的NID显著低于PR间期正常的受试者（11.1±6.0%对13.6±6.1%，P<0.001），但在多变量分析中两组之间的NID无显著差异（OR：1.48，95%CI：0.91 - 2.41；P = 0.117）。肱动脉的内皮依赖性和非内皮依赖性血管舒张均随着房室传导的延长而受损。在调整血管功能的混杂因素后，一度AVB与内皮依赖性血管舒张受损相关，但与非内皮依赖性血管舒张受损无关。从血管功能方面来看，一度AVB不太可能是预后良好的心电图异常。
