Crozatier B, Hittinger L, Chavance M
INSERM U2, Hôpital Léon Bernard, Limeil-Brévannes, France.
Am J Physiol. 1987 Dec;253(6 Pt 2):H1506-13. doi: 10.1152/ajpheart.1987.253.6.H1506.
Ventricular function was analyzed in the end-systolic and end-ejection pressure-volume diagrams in seven conscious dogs during acute aortic stenosis (AS) and sustained stenosis (SS) 24 h later. Dogs were previously instrumented with a left ventricular micromanometer and ultrasonic crystals measuring left ventricular major and minor axes and parietal wall thickness. The end-ejection pressure-calculated volume points were significantly shifted to the left during SS as compared with those obtained during AS both during a regular atrial pacing (150 beats/min) and during spontaneous heart rate. Postpacing beats were not different during AS and SS. During AS, end-systolic volume was larger after short intervals (SI) between beats (22.5 +/- 1.6 ml) than after long intervals (LI; 20.8 +/- 1.7 ml) for a smaller end-systolic pressure (P less than 0.001). This difference was minimal during SS. When SS was compared with AS, the end-systolic and end-ejection pressure-volume points were significantly shifted to the left after SI but not after LI. This suggests an acceleration of the restitution process during SS that modifies ventricular force-frequency relations and increases ventricular function as compared with AS, particularly for high heart rates.
在七只清醒犬急性主动脉狭窄（AS）及24小时后持续性狭窄（SS）期间，通过收缩末期和射血末期压力-容积图分析心室功能。这些犬之前已植入左心室微测压计以及用于测量左心室长短轴和室壁厚度的超声晶体。与在规则心房起搏（150次/分钟）及自发心率期间AS时获得的射血末期压力计算容积点相比，SS期间这些点显著向左移位。AS和SS期间起搏后搏动无差异。在AS期间，搏动间短间期（SI）后收缩末期容积（22.5±1.6毫升）大于长间期（LI；20.8±1.7毫升）后的收缩末期容积，而收缩末期压力较小（P<0.001）。在SS期间这种差异最小。当将SS与AS比较时，SI后收缩末期和射血末期压力-容积点显著向左移位，但LI后未出现这种情况。这表明与AS相比，SS期间恢复过程加速，改变了心室力-频率关系并增强了心室功能，尤其是在高心率时。
