Steinberger J, Moller J H
University of Minnesota, Division of Pediatric Cardiology, Box 94, 420 Delaware Street Southeast, Minneapolis, MN 55455, USA.
Pediatr Cardiol. 1999 Jan-Feb;20(1):27-31; discussion 32. doi: 10.1007/s002469900389.
Pulmonary valvar stenosis with intact ventricular septum is a common anomaly. This lesion poses a fixed obstruction to the right ventricular outflow. The right ventricle ejects the entire cardiac output across the stenotic valve. Right ventricular systolic pressure and oxygen demand are increased at rest and more so with exercise. Exercise tolerance in children and adults with mild valvar pulmonary stenosis is nearly normal, but is diminished in those with moderate and severe stenosis, indicating impaired ability to sustain adequate cardiac output. Following relief of stenosis, cardiac performance improves in children, but remains abnormal in adults. This appears to be related to postoperative resolution of right ventricular hypertrophy in children, whereas myocardial fibrosis may explain the lack of improvement in adults.
室间隔完整的肺动脉瓣狭窄是一种常见的先天性心脏病。该病变对右心室流出道造成固定性梗阻。右心室通过狭窄瓣膜射出全部心输出量。静息时右心室收缩压和氧需求增加，运动时更是如此。轻度肺动脉瓣狭窄的儿童和成人运动耐量接近正常，但中度和重度狭窄者运动耐量降低，提示维持足够心输出量的能力受损。狭窄解除后，儿童的心功能有所改善，但成人仍异常。这似乎与儿童术后右心室肥厚的消退有关，而心肌纤维化可能解释了成人改善不明显的原因。
