Absence of Nocturnal Fall in Blood Pressure Detected by Ambulatory Blood Pressure Monitoring in Acute Chagas Disease Patients with Oral Infection

Abstract Background The involvement of the autonomic nervous system is one of the mechanisms proposed to explain the progression of myocardial lesion in Chagas disease. Evidences have shown changes in sympathetic and parasympathetic nervous system since the acute phase of the disease, and studies to clarify the pathophysiological and prognostic value of these changes are needed. Objetives To assess blood pressure profile by ambulatory blood pressure monitoring (ABPM) in normotensive patients with acute Chagas disease (ACD) without apparent cardiac damage, and the influence of the infection on nocturnal blood pressure fall. Methods ABPM was performed with 54 patients with ACD and a control group composed of 54 age- and sex-matched normotensive individuals. The alpha level of significance (type I error rate) was set at 5%. Results In the total of 54 patients, 74.0% did not show nocturnal fall in systolic blood pressure, 53.7% did not show nocturnal fall in diastolic blood pressure, and lack of both nocturnal fall in SBP and DBP was observed in 51.8% (*p<0.05). In 12.9% of patients, there was an increase in SBP and in 18.5% increase in DBP (p<0.05). Conclusions In patients with acute Chagas disease, a significant absence of the physiological fall in both systolic and diastolic blood pressure was observed during sleep, and some of the patients showed nocturnal increase in these parameters. These findings suggest autonomic changes in the acute phase of Chagas disease. (Arq Bras Cardiol. 2020; 114(4):711-715)

摘要

背景 自主神经系统（autonomic nervous system）参与恰加斯病（Chagas disease）心肌损伤（myocardial lesion）的进展，是目前被提出的发病机制之一。已有证据显示，该疾病急性期即可出现交感和副交感神经系统（sympathetic and parasympathetic nervous system）的功能改变，目前仍需进一步研究以阐明此类改变的病理生理意义与预后价值。

研究目的 本研究旨在通过动态血压监测（ambulatory blood pressure monitoring, ABPM），评估无明显心脏损伤的急性恰加斯病（acute Chagas disease, ACD）正常血压患者的血压谱特征，并探讨感染对夜间血压下降幅度的影响。

方法 本研究共纳入54例急性恰加斯病患者，以及54例年龄、性别匹配的正常血压对照者，所有受试者均接受动态血压监测检测。本研究设定显著性检验水准α（I型错误率，type I error rate）为5%。

结果 54例急性恰加斯病患者中，74.0%未出现收缩压（systolic blood pressure, SBP）夜间下降，53.7%未出现舒张压（diastolic blood pressure, DBP）夜间下降；同时存在收缩压与舒张压夜间下降缺失的比例为51.8%（*p<0.05）。另有12.9%的患者出现收缩压升高，18.5%的患者出现舒张压升高（p<0.05）。

结论 急性恰加斯病患者睡眠期间，收缩压与舒张压的生理性夜间下降现象显著缺失，部分患者上述血压参数甚至可出现夜间升高。上述结果提示，恰加斯病急性期存在自主神经系统功能改变。(Arq Bras Cardiol. 2020; 114(4):711-715)