Gibbons Christopher H, Freeman Roy
Autonomic and Peripheral Nerve Laboratory, Dept. of Neurology, Beth Israel Deaconess Medical Center, 1 Deaconess Road, Boston, MA 02215, USA.
Clin Auton Res. 2005 Feb;15(1):40-4. doi: 10.1007/s10286-005-0227-1.
Dyspnea is a common symptom in patients with pulmonary and cardiac disease. Orthostatic hypotension is rarely considered a cause of dyspnea. We reviewed the medical records of 651 consecutive patients referred for the evaluation of dysautonomia to investigate the prevalence of dyspnea and its association with OH and other autonomic abnormalities. Dyspnea was reported by questionnaire in 30% of patients with OH, compared to 10% of age and sex matched patients without OH (P<0.05, chi(2)). There was a trend toward earlier blood pressure falls in patients with dyspnea. During autonomic testing, 25% of patients (10 of 40) with OH who reported dyspnea on the questionnaire had shortness of breath coincident with blood pressure falls during tilt table and active standing. The time to maximal blood pressure fall was shorter in patients with OH who experienced shortness of breath during testing compared to those without dyspnea (11 minutes vs. 21 minutes, P<0.05). In this study, dyspnea was frequently associated with OH. Ventilation perfusion mismatch, due to inadequate perfusion of ventilated lung apices may be the most likely underlying cause of orthostatic dyspnea in patients with OH.
呼吸困难是肺部和心脏疾病患者的常见症状。直立性低血压很少被认为是呼吸困难的原因。我们回顾了651例因自主神经功能障碍前来评估的连续患者的病历，以调查呼吸困难的患病率及其与直立性低血压（OH）和其他自主神经异常的关联。通过问卷调查，30%的OH患者报告有呼吸困难，而年龄和性别匹配的无OH患者中这一比例为10%（P<0.05，卡方检验）。呼吸困难患者的血压下降有提前的趋势。在自主神经测试期间，问卷调查中报告有呼吸困难的OH患者中有25%（40例中的10例）在倾斜试验和主动站立过程中出现呼吸急促与血压下降同时发生。与无呼吸困难的患者相比，测试期间出现呼吸急促的OH患者血压降至最低的时间更短（11分钟对21分钟，P<0.05）。在本研究中，呼吸困难常与OH相关。由于通气的肺尖灌注不足导致的通气灌注不匹配可能是OH患者直立性呼吸困难最可能的潜在原因。
