Hess O M, Felder L, Krayenbuehl H P
Department of Internal Medicine, Medical Policlinic, Cardiology, University Hospital, Zurich, Switzerland.
Herz. 1991 Apr;16(2):124-9.
Diastolic dysfunction in patients with valvular heart disease is characterized by an impaired isovolumic relaxation, a normal or even enhanced early diastolic filling rate and an increased myocardial stiffness. These abnormalities do not depend on coexisting systolic dysfunction but are often combined. Several mechanisms are responsible for the occurrence of diastolic dysfunction, such as increased wall stress, altered myocardial structure, subendocardial hypoperfusion and/or diastolic calcium overload. Postoperative regression of myocardial hypertrophy is beneficial in regard to wall stress, subendocardial hypoperfusion and calcium overload but diastolic dysfunction might become worse after valve replacement due to a relative increase in interstitial fibrosis consequent to the decrease in myocyte mass (= myocardial remodeling). Persisting diastolic dysfunction with a substantial rise in left ventricular filling pressure can be observed during dynamic exercise in postoperative patients with preoperative severe pressure overload hypertrophy. Thus, diastolic dysfunction can be present as a primary derangement of cardiac function and can be unmasked as an abnormal response of diastolic filling pressure during exercise.
心脏瓣膜病患者的舒张功能障碍表现为等容舒张受损、舒张早期充盈率正常甚至增强以及心肌僵硬度增加。这些异常并不取决于并存的收缩功能障碍，但常合并存在。舒张功能障碍的发生有多种机制，如壁应力增加、心肌结构改变、心内膜下灌注不足和/或舒张期钙超载。心肌肥厚术后的消退对壁应力、心内膜下灌注不足和钙超载有益，但由于心肌细胞质量减少导致间质纤维化相对增加（即心肌重塑），瓣膜置换术后舒张功能障碍可能会加重。术前有严重压力负荷性肥厚的术后患者在动态运动期间可观察到持续的舒张功能障碍伴左心室充盈压显著升高。因此，舒张功能障碍可作为心脏功能的原发性紊乱存在，并可在运动期间作为舒张充盈压的异常反应而显现出来。
