2010-08-012024-05-13https://scholars.lib.ntu.edu.tw/handle/123456789/646932摘要：冠心病是全球的主要死因，嚴重的冠心病人通常具有明顯的症狀或徵侯，然而大多數的冠心病人通常歷經數十年並無顯著的症狀。為了避免心導管等侵入性檢查所造成的傷害及昂貴的費用，在評估病人是否有冠心病時，非侵入性診斷工具變得益形重要。然而以非侵入性方法來診斷心肌缺氧，至今仍為臨床工作上的一項挑戰。由於靜態的12 -導極心電圖在這類病人通常是正常的，因此過往常以運動心電圖、催迫性超音波心圖、或核醫影像檢查來判定病人是否有冠心病，然而這些檢查或受限於偵測率不高，或受限於需要催迫或具放射性。新一代的影像學技術，如多切電腦斷層攝影或磁振造影顯示具較高的靈敏度，然其診斷特異性仍低，且仍受限於須使用顯影劑或仍具相當的放射性，更重要的是其檢查費用昂貴。有鑑於此，本實驗室與本校物理系、師大光電所、韓國延世大學、韓國量測研發中心共同研發64 通道心磁圖在冠心病之應用。由於心臟電氣活動所產生的磁性訊號具有非接觸、非侵入、無放射性之特點，因此心磁圖對解決以上討論之課題有其先天上之優勢，並可快速且精確地紀錄心臟二維空間信號，有助於發展實用的軟體程式。過去的研究顯示局部的心肌缺血會造成動作電位變短，因而使心肌動作電位期間在空間分佈上產生瀰散的現象，利用此原理可早期偵測到心肌缺氧。我們已發展出幾種參數（如SIQTc,QTd, T wave propagation pattern），不但能在不需催迫心臟的情況下就能快速及準確的診斷冠狀動脈阻塞，且能在二維空間上定位心肌缺氧或存活之部位。然而利用此技術臨床上診斷穩定型冠心病的精確度如何，它是否能用來偵測心肌梗塞後存活的心肌組織，相關文獻仍極少。另外，近年來冠狀動脈介入性治療盛行，然而血管的再阻塞亦成為臨床上一重要之課題。病人症狀的再發顯然不是一個敏感的指標，但是現今的臨床指引仍是建議只有在病人再發心絞痛的情況下才應施行催迫性檢查，乃因此類檢查均具有催迫或放射性的風險，那麼此時不需催迫、無放射性之心磁圖又將具備相當之優勢。因此本三年期研究計劃將進行一系列工作來開發新的心磁圖參數，並進而探討: (1)臨床上心磁圖是否能精確的診斷穩定型冠心病；(2)心磁圖是否能用來偵測及定位心肌梗塞後存活的心肌組織；(3)心磁圖是否能靈敏的偵測到冠狀動脈介入性治療後血管的再阻塞，並進一步判定病人的預後。<br> Abstract: Coronary artery disease (CAD) is the leading cause of death worldwide. Whilethe symptoms and signs of CAD are noted in the advanced state of disease, mostindividuals with coronary artery disease show no evidence of disease for decades. Inassessing patients with confirmed or suspected CAD, noninvasive strategies are ofincreasing clinical importance to avoid serious side effects and expanding costs thatare often associated with invasive methods. However, the noninvasive diagnosis ofcardiac ischemia related to CAD remains a clinical challenge. The 12-leadelectrocardiogram (ECG) at rest is frequently normal in such patients and thepredictive value of other methods such as exercise-ECG, stress echocardiography ornuclear imaging is often limited and may be associated with a certain risk. Newerimaging techniques including multislice computed tomography or magnetic resonanceimaging demonstrate good values for sensitivity but specificity remains unsatisfactoryat present and some of the methods require contrast medium or radiation, and mostimportantly, their expense is all very high.Magnetocardiography (MCG) is a noninvasive and risk-free technique allowingbody surface recording of the magnetic fields generated by the electrical activity ofheart. Recent research has been recognized for its outstanding ability to detectpatients with coronary artery disease (CAD). Previous study has demonstrated thatdispersion of action potential duration increased during regional ischemia in isolatedrabbit heart. Greater than normal levels of repolarizaiton dispersion may allow earlydiagnosis of ischemic heart disease. We have utilized a 64-channel MCG system todetect the time-dependent magnetocardiac signals that are spatially distributed overthe heart. To achieve efficient acquisition and analysis, we have proposed somemethods to construct and analyze the 2D signals recorded from MCG (ex. SIQTc, QTd,T wave propagation pattern). We showed the possibility for screening and localizingthe myocardial ischemia or viability through analyzing the time-dependent area ratioof the T wave propagation. However, whether or not the regional repolarizationheterogeneity could be detected by MCG in patients with stable CAD remainedunclear. The diagnostic accuracy of MCG by quantification of myocardialrepolarization heterogeneity for assessment of stable CAD is also unknown.In view of the high morbidity and mortality associated with revascularizationprocedures, careful selection of patients who may benefit from revascularizationprocedures appears to be warranted. In addition, assessing restenosis of CAD afterpercutaneous coronary interventions has also become a major challenge incontemporary cardiology. Symptom status is an unreliable predictor of ischemia afterrevascularization procedures and silent restenosis is still fairly common. Nevertheless,current guidelines recommend stress testing only in patients with recurrent symptoms,because the standard stress tests have the risk of stress or irradiation. These makethe MCG examination promising for this application, because it has no need to stressthe patients, no radiation, and is convenient to perform with high throughput. However,there have been only few studies about its application for evaluating myocardialviability and there has been no study to use this examination for predicting patient’sprognosis.Therefore, in this 3-year project, we shall perform a series of work to validate thediagnostic accuracy of MCG for detecting CAD. New technologies and parameters willbe developed in this study, to validate its diagnostic feasibility for myocardial viability,and its usefulness for risk stratification of patients after coronary revascularization.