Sluysmans T, Sanders S P, van der Velde M, Matitiau A, Parness I A, Spevak P J, Mayer J E, Colan S D
Department of Cardiology, Children's Hospital, Boston, MA 02115.
Circulation. 1992 Dec;86(6):1753-61. doi: 10.1161/01.cir.86.6.1753.
Before the era of the Fontan procedure, the typical course of patients with single left ventricle (LV) consisted of heart failure and death during the second or third decade of life. Despite the advent of effective palliative therapy, ventricular dysfunction remains a significant clinical problem for these patients.
To investigate the causes of ventricular dysfunction in these patients and to determine whether Fontan-type repair reverses deterioration of LV function, the ventricular dimensions, volume, shape, wall stress, and systolic function were determined by echocardiography in 84 patients 0.2-35 years old with double-inlet single LV or tricuspid atresia. Measurements were obtained in 67 patients after palliation (arterial shunt or pulmonary artery band) and in 47 patients a median of 4.4 years after a Glenn (n = 9) or a Fontan operation (n = 38). Before a Fontan procedure, ventricular volumes were 2 to 3 times normal. Ventricular afterload, assessed as circumferential and meridional end-systolic wall stress, became abnormal after 2 years of age. With age, LV shape changed progressively from ellipsoidal to spherical, as indicated by the decrease in long axis:short axis ratio from normal (1.9) toward unity. Concomitantly, the ratio of circumferential to meridional end-systolic wall stress fell from 1.3 to unity, the ratio of a sphere at equilibrium. This age-related change in shape and load occurred in concert with progressive deterioration of LV systolic function and contractility. Aortic oxygen saturation, an indicator of pulmonary blood flow and therefore volume work in single-ventricle physiology, was inversely and independently correlated with contractility. In the group of patients in whom a Glenn or a Fontan operation was performed at < 10 years of age, ventricular dimensions, volumes, and wall stress diminished and LV function and contractility improved after surgery (p < 0.001). In patients undergoing surgery after 10 years of age, few had improvement of LV function after surgery. Postoperative ventricular function and contractility were inversely related to age at surgery and to aortic oxygen saturation measured before surgery.
Although Fontan-type repair of single ventricle early in life is associated with reversal of the abnormal contractile mechanics associated with age and volume load, this capacity for recovery diminishes with age at surgery.
在Fontan手术时代之前，单左心室（LV）患者的典型病程是在生命的第二个或第三个十年出现心力衰竭和死亡。尽管出现了有效的姑息治疗方法，但心室功能障碍仍然是这些患者的一个重大临床问题。
为了研究这些患者心室功能障碍的原因，并确定Fontan型修复是否能逆转左心室功能的恶化，我们通过超声心动图对84例年龄在0.2至35岁之间、患有双入口单左心室或三尖瓣闭锁的患者进行了心室尺寸、容积、形状、壁应力和收缩功能的测定。在67例接受姑息治疗（动脉分流或肺动脉环扎）的患者以及47例在Glenn手术（n = 9）或Fontan手术（n = 38）后中位时间为4.4年的患者中进行了测量。在Fontan手术前，心室容积是正常的2至3倍。以圆周和子午线收缩末期壁应力评估的心室后负荷在2岁后变得异常。随着年龄的增长，左心室形状逐渐从椭圆形变为球形，长轴与短轴之比从正常的（1.9）降至1。与此同时，圆周与子午线收缩末期壁应力之比从1.3降至1，即平衡状态下球体的比例。这种与年龄相关的形状和负荷变化与左心室收缩功能和收缩性的逐渐恶化同时发生。主动脉血氧饱和度是肺血流量的指标，因此也是单心室生理学中容量功的指标，它与收缩性呈负相关且独立相关。在10岁之前接受Glenn或Fontan手术的患者组中，术后心室尺寸、容积和壁应力减小，左心室功能和收缩性改善（p < 0.001）。在10岁之后接受手术的患者中，很少有人术后左心室功能得到改善。术后心室功能和收缩性与手术时的年龄以及术前测量的主动脉血氧饱和度呈负相关。
尽管早年对单心室进行Fontan型修复与逆转与年龄和容量负荷相关的异常收缩力学有关，但这种恢复能力会随着手术年龄的增长而降低。
