Danford D A, Huhta J C, Gutgesell H P
J Thorac Cardiovasc Surg. 1985 Apr;89(4):610-5.
The effects of volume and pressure loading of the left ventricle on posterior wall thickness and left ventricular wall stress in transposition of the great arteries were studied by combining echocardiographic and cardiac catheterization data. Pure volume loading with low left ventricular pressure resulted in little or no thickening of the left ventricular posterior wall (0.52 mm/log month). Pressure loading to levels above half of the right ventricular pressure was associated with thickening (2.80 to 3.89 mm/log month); however, further increase in pressure or volume load did not significantly alter the rate of thickening. Estimates of ventricular wall stress using a simple radius/wall thickness ratio may be misleading. However, if allowance is made for variable ventricular geometry and pressure, estimated wall stress is constant in transposition and is approximately equal to that reported previously in patients with normally related great arteries. The walls of low-pressure left ventricles in patients with transposition are demonstrably thinner than those of high-pressure left ventricles by age 1 to 3 months (2.67 versus 3.52 mm). Surgical procedures to use the left ventricle for systemic work, such as the arterial switch operation, should be performed in the first month of extrauterine life. Preparatory operations, if necessary prior to arterial switch, should load the left ventricle to greater than half systemic pressure.
通过结合超声心动图和心导管检查数据，研究了大动脉转位时左心室容量和压力负荷对后壁厚度和左心室壁应力的影响。低左心室压力下的单纯容量负荷导致左心室后壁增厚很少或没有增厚（0.52毫米/对数月）。压力负荷达到右心室压力一半以上时会出现增厚（2.80至3.89毫米/对数月）；然而，压力或容量负荷的进一步增加并未显著改变增厚速率。使用简单的半径/壁厚比来估计心室壁应力可能会产生误导。然而，如果考虑到心室几何形状和压力的变化，转位时估计的壁应力是恒定的，并且大约等于先前报道的正常大动脉关系患者的壁应力。到1至3个月大时，大动脉转位患者中低压左心室的壁明显比高压左心室的壁薄（2.6７对3.52毫米）。使用左心室进行体循环工作的外科手术，如动脉调转术，应在宫外生活的第一个月内进行。如果在动脉调转术前有必要进行预备手术，应将左心室负荷增加到大于体循环压力的一半。
