神經性暈厥症的診斷：同步多元化監測的傾斜床測驗

Diagnosis for Neurogenic Syncope: Head-up Tilt Test Using Multi-Modality Monitoring

暈厥為臨床上常見的問題，尤其是神經性暈厥症常面臨診斷的困難。本研究嘗試發展完整的傾斜床測驗評估神經性暈厥症的病人。自2000年4月所有因為不明原因暈厥而接受傾斜床測驗，共有80例。前半組受測者接受單獨以長時間傾斜40分鐘，共有37例；後半組受測者接受傾斜15分鐘，再使用舌下硝化甘油噴劑15分鐘，共有43例。血管迷走反應定義為血行動力的突發性變化，非血管迷走反應定義為漸進性變化，依核心的生理變化包含：心跳過度增加、心律不反應、血壓降低、腦血流速降低合併阻力增加。單獨長時間傾斜組測驗的結果為：陰性反應26人(70%)，非血管迷走反應11人(30%)，血管迷走反應0人；使用舌下硝化甘油組測驗的結果為：陰性反應16人(37%)，非血管迷走反應13人(30%)，血管迷走反應14人(33%)。兩組統計上有明顯差別(P=0.0001)；使用硝化甘油可以大幅提高血管迷走反應的檢測率，但未改變非血管迷走反應的檢測率。我們提出兩階段傾斜、使用低劑量舌下硝化甘油噴劑、同步監測血壓、心跳、呼吸、腦血流速、腦波的傾斜床測驗方法，作為診斷和研究神經性暈厥症的工具。

Syncope is a common but challenging clinical problem, and tilt table test is an efficacious tool for confirming the clinical diagnosis of neurally mediated syncope. Eighty consecutive patients with unexplained syncope were thoroughly assessed by head-up tilt test. Of these patients, the initial 37 underwent drug-free tilt test at 60° for 40 minutes, the following 43 underwent tilt test without medication for 15 minutes; then, if syncope did not occur, continued to be tilted for further 15 minutes with 0.4mg sublingual nitroglycerin provocation. Positive responses on tilt table test were classified vasovagal response and non-vasovagal response. Vasovagal response was defined sudden onset of substantial hypotension associated with various degree of bradycardia. Non-vasovagal response was defined gradual onset of substantial change of heart rate, blood pressure, or cerebral blood flow velocity. Twenty-six (70%) negative responses, 11 (30%) non-vasovagal responses and 0 vasovagal response were observed during drug-free tilt test; 16 (37%) negative responses, 13 (30%) non-vasovagal responses and 14 (33%) vasovagal responses were observed during nitroglycerin tilt test. The addition of nitroglycerin to tilt test significantly increased the positive rate of vasovagal response but maintained that of non-vasovagal response. The aim of present study was to propose a two-stage head-up tilt test protocol using low-dose sublingual nitroglycerin provocation and multi-modality monitoring including cerebral blood flow velocity and electroencephalography for diagnosis and classification of neurally mediated syncope.