緩流型冠狀動脈X症候群病人之運動心電圖

Treadmill Exercise ECG in Syndrome X Patients with Slow Coronary Flow

林慧君(Hui-Chun Lin) ； 侯嘉殷(Jia-Yin Hou) ； 周友三(Yu-San Chou) ； 蔡正河(Cheng-Ho Tsai)

《台灣醫學》 10卷6期 (2006/11) Pp. 688-694

https://doi.org/10.6320/FJM.2006.10(6).03

摘要

部分X症候群病人，血管攝影時出現冠狀動脈緩流現象，此現象被視為心肌缺氧標誌。臨床應用aV(下標 f)，V5二導程運動前後Q，R，和S波振輻改變，所謂Athens QRS分數，相較傳統利用ST段下降變化為診斷依據，不但可提高冠狀動脈疾病診斷之準確性，亦可提供嚴重性之評估。本研究採用Athens QRS分數來探討緩流型X症候群病人運動時誘發之心肌缺氧，並比較顯著性冠狀動脈狹窄病人和正常流速之X症候群病人，來評估其心肌缺氧之嚴重性。此回溯性研究包括65位運動心電圖呈陽性病人，並接受冠狀動脈血管攝影檢查。其中18位為正常流速之X症候群病人，稱之A組，另外20位符合冠狀動脈緩流現象，稱之B組，其餘27位被証實為顯著性冠狀動脈狹窄(冠心病)，稱之C組。所有病人均接受多階段布魯士(multi-stage Bruce protocol)運動心電圖測試，計算Athens QRS分數，並記錄最大代謝當量、最高與基礎心跳、血壓、到達預期目標心跳比值、運動總時間和最大ST段變化量。Athens QRS分數等於(DR-DQ-DS)aV(下標 f)+(DR-DQ-DS)V5，其中DR表運動前減去運動剛停止時R波振輻，其他類推。結果發現A，B組病人QRS分數之平均值皆小於5mm，其中緩流型X症候群病人明顯高於冠心病人（4.6±4.8比1.4±3.4，P值=0.005），但低於正常流速之X症候群病人（4.6±4.8比7.2±4.1，P值=0.04）。意謂緩流型X症候群病人，運動時可誘發心肌缺氧，但冠心病人的心肌缺氧較嚴重。除了最快運動心跳數與最高收縮壓乘積外，其他重要參考變數如最大代謝當量、達到預期目標心跳數比值，可用於評估左心室功能及預後，緩流型X症後群病人皆明顯高於冠心病人，與正常流速之X症候群病人無明顯差異，其預後佳。

關鍵字

緩流型X症候群 ； 冠狀動脈緩流現象 ； Athens QRS分數 ； 心肌缺氧

並列摘要

A subgroup of syndrome X patients was determined to have myocardial ischemia by the appearance of coronary flow during angiography. The exercise-induced Q, R, and S wave amplitude changes in leads aV(subscript f) and V5 (Athens QRS score) have been reported to be a reliable marker of exercise-induced myocardial ischemia. Our study compared the severity of exercise-induced myocardial ischemia between slow coronary flow, significant coronary arterial disease (CAD) and normal coronary flow using Athens QRS score. This retrospective study include 18 patients with normal coronary flow of syndrome X (group A), 20 patients with slow coronary flow of syndrome X (group B) and 27patients with significant CAD (group C). All study subjects underwent treadmill exercise testing using the multi-stage Bruce protocol. The amplitudes of Q, R, and S wave in leads aV(subscript f) and V5 were measured manually before and immediately after exercise. The QRS score was calculated by subtracting the Q, R, and S wave differences in leads aV(subscript f) and V5. In addition, target heart rate achieved ratio, baseline and peak systolic and diastolic blood pressure, maximal metabolic equivalents, exercise duration and ST segment changes were recorded. The demographic characteristics of three groups were similar. The mean exercise QRS score in B&C groups were lower than 5mm. Group B had a significantly higher value than group C (4.63±4.8 vs 1.41±3.4, p=0.005, respectively), but lower value than group A (1.4±3.4 vs 7.2±4.1, p=0.04, respectively). Other parameters such as maximal metabolic equivalent, target heart rate achieved ratio, exercise duration were also significantly higher than group C. There were no difference between group A&B. However, the maximal ST-segment depression among three groups had no difference. The data suggest that slow coronary flow phenomenon may lead to myocardial ischemia even in the absence of obstructed major epicardial coronary arteries. Despite exercise-induced myocardial ischemia in patients with slow coronary flow, the higher Athens QRS score and metabolic equivalents indicates lower severity and better prognosis.

並列關鍵字

syndrome X ； Athens QRS score ； slow coronary flow phenomenon ； myocardial ischemia