Nicholson A A, Caplin J L, Steventon D M
Department of Radiology, Hull Royal Infirmary.
Clin Radiol. 1994 Jan;49(1):14-8. doi: 10.1016/s0009-9260(05)82907-1.
Amiodarone is strongly tissue-bound and serum levels are a poor guide to therapeutic efficacy. The electrocardiographic measure of the QT interval corrected for heart rate (QTc) is a better guide but is unhelpful in patients with bundle branch block or U-waves on the electrocardiogram. Myocardial amiodarone levels are the most accurate guide but are not easy to obtain. There is, however, a relationship between myocardial concentration and hepatic concentration of amiodarone and its metabolites. Since amiodarone contains iodine, and there is hepatic uptake, the increased hepatic attenuation from single slice computed tomography was compared with serum levels and the electrocardiographic QTc in 12 patients before and during amiodarone therapy. Hepatic attenuation increased by a mean value of 18.25 HU over a 12 month study period. This increase correlated well with increased QTc (r = 0.83) and with serum amiodarone levels (r = 0.89), but less well with serum desethyl amiodarone levels (r = 0.43). An iodine-containing phantom was used to construct a curve of attenuation against iodine concentration in mol/l. Thus an indirect measurement of amiodarone concentration in g/l wet weight of liver could be determined.
胺碘酮与组织结合紧密，血清水平对治疗效果的指导作用不佳。校正心率后的QT间期（QTc）的心电图测量是一个更好的指导指标，但对于存在束支传导阻滞或心电图上有U波的患者则无帮助。心肌胺碘酮水平是最准确的指导指标，但不易获得。然而，胺碘酮及其代谢产物的心肌浓度与肝脏浓度之间存在关联。由于胺碘酮含碘，且有肝脏摄取，因此在12例患者胺碘酮治疗前及治疗期间，将单层计算机断层扫描显示的肝脏衰减增加情况与血清水平及心电图QTc进行了比较。在为期12个月的研究期间，肝脏衰减平均增加了18.25HU。这种增加与QTc增加（r = 0.83）及血清胺碘酮水平（r = 0.89）密切相关，但与血清去乙基胺碘酮水平的相关性较差（r = 0.43）。使用含碘模型构建了衰减相对于碘浓度（mol/l）的曲线。因此，可以间接测定肝脏每克湿重中胺碘酮的浓度（g/l）。
