Martin G R, Chauvin L, Short B L
Department of Pediatrics, Children's National Medical Center, Washington, D.C.
J Pediatr. 1991 Jun;118(6):944-8. doi: 10.1016/s0022-3476(05)82216-4.
To determine the effects of afterload reduction on cardiac performance during partial cardiopulmonary bypass, we administered hydralazine to infants who were either normotensive (n = 11) or hypertensive (n = 12) 1 hour after extracorporeal membrane oxygenation (ECMO) was begun. Load-dependent and load-independent measures of cardiac performance and indexes of cerebral blood flow were measured. Infants in both groups had similar weight, heart rate, blood pressure, and inotropic support before ECMO. Shortening fraction was normal in both groups before ECMO (47 +/- 11% vs 49 +/- 10%; p greater than or equal to 0.05), decreased during ECMO (31 +/- 18% vs 39 +/- 12%; p greater than or equal to 0.05), and did not change after administration of hydralazine (31 +/- 12% vs 37 +/- 8%; p greater than or equal to 0.05). Cardiac output was normal in both groups before ECMO (176 +/- 71 vs 157 +/- 72 ml/kg per minute; p greater than or equal to 0.05), decreased during ECMO (120 +/- 80 vs 105 +/- 64 ml/kg per minute; p greater than or equal to 0.05), and did not change after hydralazine administration. Velocity of circumferential fiber shortening, an index of contractility (circumference per second), was normal in both groups before ECMO (1.96 +/- 0.57 vs 1.90 +/- 0.43 circ/sec; p greater than or equal to 0.05), decreased during ECMO (1.18 +/- 0.83 vs 1.56 +/- 0.58 circ/sec; p greater than or equal to 0.05), and did not change after hydralazine administration. The relationship between velocity of circumferential fiber shortening and wall stress was similar in both groups before ECMO, during ECMO, and after hydralazine administration. The cerebral blood flow resistance index was similar in both groups before ECMO (0.70 +/- 0.16 vs 0.70 +/- 0.20; p greater than or equal to 0.05), decreased during ECMO (0.45 +/- 0.13 vs 0.43 +/- 0.09; p greater than or equal to 0.05), and did not change after administration of hydralazine. We conclude that hydralazine does not improve cardiac performance during ECMO.
为了确定在部分体外循环期间后负荷降低对心脏功能的影响，我们在开始体外膜肺氧合（ECMO）1小时后，对血压正常（n = 11）或高血压（n = 12）的婴儿给予了肼屈嗪。测量了心脏功能的负荷依赖性和负荷非依赖性指标以及脑血流指数。两组婴儿在ECMO之前的体重、心率、血压和正性肌力支持情况相似。两组在ECMO之前缩短分数均正常（47±11%对49±10%；p≥0.05），在ECMO期间降低（31±18%对39±12%；p≥0.05），并且在给予肼屈嗪后没有变化（31±12%对37±8%；p≥0.05）。两组在ECMO之前心输出量均正常（176±71对157±72 ml/kg每分钟；p≥0.05），在ECMO期间降低（120±80对105±64 ml/kg每分钟；p≥0.05），并且在给予肼屈嗪后没有变化。圆周纤维缩短速度，一项收缩性指标（每秒圆周数），在两组ECMO之前均正常（1.96±0.57对1.90±0.43圆周/秒；p≥0.05），在ECMO期间降低（1.18±0.83对1.56±0.58圆周/秒；p≥0.05），并且在给予肼屈嗪后没有变化。在ECMO之前、ECMO期间以及给予肼屈嗪之后，两组圆周纤维缩短速度与壁应力之间的关系相似。两组在ECMO之前脑血流阻力指数相似（0.70±0.16对0.70±0.20；p≥0.05），在ECMO期间降低（0.45±0.13对0.43±0.09；p≥0.05），并且在给予肼屈嗪后没有变化。我们得出结论，在ECMO期间肼屈嗪不能改善心脏功能。
