放射性核素显像在冠心病预后估测中的应用

Prognostic Assessment in Coronary Artary Disease: Role of Myocardial Perfusion Imaging and Radionuclide Angiography

对于冠心病患者,治疗的主要目的是要降低随后发生心肌梗塞、严重心律不齐和心因性死亡的发病率,因此,区分低危病人与易发生心脏事件的高危患者是非常必要的,这有助于临床医师决定最佳治疗方案。对冠心病患者进行预后估测的无创性方法非常重要,结合心电图检查进行核素心肌灌注显像与心室造影是目前临床上最为广泛应用的方法,资料显示若患者心肌灌注显像正常,无运动或药物试验可诱发的心肌缺血或缺血性ST段改变,LVEF>50％,预后很好;如患者系多支血管病变,在心肌灌注显像中呈现多室壁灌注缺损区,存在有负荷试验诱发的可逆性心肌缺血,往往揭示预后恶劣,对于低危病人当以内科治疗为宜,对于高危患者则应采取更为积极的治疗措施,如血管再通术,以减少心脏意外的发生,改善生活质量,延长生命。

Myocardial perfusion imaging and ra-dionuclide ventriculography have evolved from strictlydiagnostic tool for determining the presence or ab-sence of coronary artery disease to wildly used ad-juncts for risk stratification that has become increaselyvaluable for guiding patient management strategies. Theextent of myocardial hypoperfusion reflected by thenumber of myocardial perfusion defects with inducibleischemia (as a marker of jeopardized viable my-ocardium) and the degree of stress ischemic LV dys-function rdflected by abnormal lung uptake, LV cavi-ty dilatation and abnormal LVEF appear to be impor-tani variable for predicting future cardiac events. Pa-tients with normal perfusion scan or only a single irre-versible perfusion abnormality and normal LVEF have abetter prognosis. The risk of a cardiac event was lessthan 1%. Multiple perfusion defects, some showing signifi-cant stress inducible ischemia with decreased LVEF, ab-normal lung uptake and/or transient LV cavity dilatationare markers of high risk for CAD with an increased sub-sequent cardiac event rate, the greater the extent of CADand the worse the LV function, the lower was the sur-vival rate. Patients identified as low risk are probablybest managed medically. Those identified to be at highrisk are most likely to benefit from additional interven-tional management.