Kuehne Titus, Gleason B Kelly, Saeed Maythem, Turner Daniel, Weil Jochen, Teitel David F, Higgins Charles B, Moore Phillip
Department of Pediatrics and Radiology, University of California, San Francisco, 94143, USA.
J Appl Physiol (1985). 2005 Oct;99(4):1422-7. doi: 10.1152/japplphysiol.00324.2005. Epub 2005 Jun 23.
This study was conducted to determine the effects of chronic combined pulmonary stenosis and pulmonary insufficiency (PSPI) on right (RV) and left ventricular (LV) function in young, growing swine. Six pigs with combined PSPI were studied, and data were compared with previously published data of animals with isolated pulmonary insufficiency and controls. Indexes of systolic function (stroke volume, ejection fraction, and cardiac functional reserve), myocardial contractility (slope of the end-systolic pressure-volume and change in pressure over time-end-diastolic volume relationship), and diastolic compliance were assessed within 2 days of intervention and 3 mo later. Magnetic resonance imaging was used to quantify pulmonary insufficiency and ventricular volumes. The conductance catheter was used to obtain indexes of the cardiac functional reserve, diastolic compliance, and myocardial contractility from pressure-volume relations acquired at rest and under dobutamine infusion. In the PSPI group, the pulmonary regurgitant fraction was 34.3 +/- 5.8%, the pressure gradient across the site of pulmonary stenosis was 20.9 +/- 20 mmHg, and the average RV peak systolic pressure was 70% systemic at 12 wk follow-up. Biventricular resting cardiac outputs and cardiac functional reserves were significantly limited (P < 0.05), LV diastolic compliance significantly decreased (P < 0.05), but RV myocardial contractility significantly enhanced (P < 0.05) compared with control animals at 3-mo follow-up. In the young, developing heart, chronic combined PSPI impairs biventricular systolic pump function and diastolic compliance but preserves RV myocardial contractility.
本研究旨在确定慢性肺动脉狭窄合并肺动脉瓣关闭不全（PSPI）对幼年生长猪右心室（RV）和左心室（LV）功能的影响。对6只患有PSPI的猪进行了研究，并将数据与先前发表的单纯肺动脉瓣关闭不全动物和对照组的数据进行了比较。在干预后2天内及3个月后评估收缩功能指标（每搏输出量、射血分数和心功能储备）、心肌收缩力（收缩末期压力-容积斜率和压力随时间变化-舒张末期容积关系）以及舒张顺应性。使用磁共振成像来量化肺动脉瓣关闭不全和心室容积。通过在静息状态和多巴酚丁胺输注下获取的压力-容积关系，使用电导导管获得心功能储备、舒张顺应性和心肌收缩力的指标。在PSPI组中，肺动脉反流分数为34.3±5.8%，肺动脉狭窄部位的压力梯度为20.9±20 mmHg，在12周随访时右心室平均收缩压峰值为体循环压力的70%。与对照组动物相比，在3个月随访时，双心室静息心输出量和心功能储备显著受限（P<0.05），左心室舒张顺应性显著降低（P<0.05），但右心室心肌收缩力显著增强（P<0.05）。在年轻的发育心脏中，慢性PSPI合并症损害双心室收缩泵功能和舒张顺应性，但保留右心室心肌收缩力。
