Auffermann W, Wagner S, Holt W W, Buser P T, Kircher B, Schiller N B, Lim T H, Wolfe C L, Higgins C B
Department of Radiology, University of California School of Medicine, San Francisco.
Am Heart J. 1991 Jun;121(6 Pt 1):1750-8. doi: 10.1016/0002-8703(91)90022-a.
The current study used cine magnetic resonance imaging to determine the effect of increasing severity of valvular regurgitation on systolic wall stress and to demonstrate that wall stress was disproportionately increased in relation to the severity of regurgitation in patients with myocardial disease. A total of 39 patients with predominantly mitral (n = 22) or aortic (n = 17) regurgitation with (n = 13) and without (n = 26) myocardial disease and 10 normal volunteers were examined with cine magnetic resonance imaging (MRI) at 1.5 T. Left ventricular (LV) cardiac output (CO) and peak systolic (PS) wall stress (WS) and end-systolic (ES) WS were calculated from blood pressure recordings, carotid pulse tracings, and wall thickness (h) and diameter (D) measurements obtained from cine MRI. Patients were classified into three degrees of severity according to their LV regurgitant volume (RV). Myocardial disease was defined by an ejection fraction (EF) of less than 40%. Mean LV EF was 61 +/- 3% in normal volunteers, 64 +/- 3% in patients with regurgitation, and 25 +/- 2% in patients with myocardial disease. LV CO was directly related to RV in patients without myocardial disease, whereas it was disproportionately low in relation to RV in patients with myocardial disease. PS WS was significantly higher in severe mitral and/or aortic regurgitation compared with moderate, mild, and no mitral and/or aortic regurgitation. Compared with the degree of regurgitation, PS WS was disproportionately higher in patients with myocardial disease. Thus LV CO and WS rise progressively with increasing severity of regurgitation. Disproportionately high systolic WS relative to RV indicates the presence of myocardial disease.(ABSTRACT TRUNCATED AT 250 WORDS)
本研究采用电影磁共振成像来确定瓣膜反流严重程度增加对收缩期壁应力的影响，并证明在心肌病患者中，壁应力相对于反流严重程度不成比例地增加。共有39例主要为二尖瓣反流（n = 22）或主动脉瓣反流（n = 17）的患者，其中13例合并心肌病，26例不合并心肌病，以及10名正常志愿者接受了1.5T的电影磁共振成像（MRI）检查。根据血压记录、颈动脉脉搏描记图以及电影MRI获得的壁厚（h）和直径（D）测量值，计算左心室（LV）心输出量（CO）、收缩期峰值（PS）壁应力（WS）和收缩末期（ES）WS。根据左心室反流容积（RV）将患者分为三个严重程度等级。心肌病定义为射血分数（EF）小于40%。正常志愿者的平均左心室EF为61±3%，反流患者为64±3%，心肌病患者为25±2%。在无心肌病的患者中，左心室CO与RV直接相关，而在有心肌病的患者中，左心室CO相对于RV不成比例地低。与中度、轻度以及无二尖瓣和/或主动脉瓣反流相比，重度二尖瓣和/或主动脉瓣反流患者的PS WS显著更高。与反流程度相比，心肌病患者的PS WS更高。因此，随着反流严重程度增加，左心室CO和WS逐渐升高。相对于RV而言，收缩期WS过高表明存在心肌病。（摘要截选至250词）
