Langer A, Freeman M R, Josse R G, Steiner G, Armstrong P W
Division of Cardiology, St. Michael's Hospital, Toronto, Ontario, Canada.
Am J Cardiol. 1991 May 15;67(13):1073-8. doi: 10.1016/0002-9149(91)90868-l.
The prevalence of silent myocardial ischemia and its relation to autonomic dysfunction and pain threshold was studied in 58 men with diabetes mellitus and without cardiac symptoms. All patients underwent 48-hour ambulatory electrocardiographic monitoring and exercise testing after assessment of their autonomic function and pain threshold. Silent myocardial ischemia, defined as greater than or equal to 1 mm of ST-segment depression on either exercise testing or ambulatory electrocardiographic monitoring, was corroborated by exercise-induced reversible defect(s) on tomographic thallium scintigraphy. Autonomic function was assessed by heart rate response to: (1) Valsalva maneuver, (2) deep breathing, and (3) upright posture, as well as by diastolic blood pressure response to sustained handgrip and systolic blood pressure response to upright posture. Autonomic dysfunction was defined as greater than or equal to 2 abnormal responses. Pain threshold measurements were performed using electrical cutaneous stimulation of both forearms. Of the 58 diabetic patients, 21 were found to have autonomic dysfunction (36%). Silent myocardial ischemia was detected in 10 patients (17%), and was significantly more frequent in patients with than without autonomic dysfunction (38 vs 5%, p = 0.003). There was no difference in the electrical pain threshold or tolerance in subjects with and without silent myocardial ischemia. It is concluded that silent myocardial ischemia in asymptomatic diabetic men occurs frequently and in association with autonomic dysfunction, suggesting that diabetic neuropathy may be implicated in the mechanism of silent myocardial ischemia.
对58名无心脏症状的糖尿病男性患者进行了无症状心肌缺血的患病率及其与自主神经功能障碍和痛阈关系的研究。所有患者在评估自主神经功能和痛阈后，均接受了48小时动态心电图监测和运动试验。无症状心肌缺血定义为运动试验或动态心电图监测时ST段压低≥1mm，断层心肌铊闪烁显像显示运动诱发的可逆性缺损可证实这一点。通过心率对以下情况的反应评估自主神经功能：（1）瓦尔萨尔瓦动作，（2）深呼吸，（3）直立姿势，以及舒张压对持续握力的反应和收缩压对直立姿势的反应。自主神经功能障碍定义为异常反应≥2项。使用电刺激双侧前臂进行痛阈测量。58名糖尿病患者中，21名被发现存在自主神经功能障碍（36%）。10名患者（17%）检测到无症状心肌缺血，有自主神经功能障碍的患者比无自主神经功能障碍的患者更频繁地出现无症状心肌缺血（38%对5%，p = 0.003）。有无无症状心肌缺血的受试者在电痛阈或耐受性方面无差异。得出的结论是，无症状糖尿病男性中无症状心肌缺血频繁发生且与自主神经功能障碍相关，提示糖尿病神经病变可能与无症状心肌缺血的机制有关。
