Hoit B D, Shao Y, Gabel M, Walsh R A
Department of Internal Medicine, University of Cincinnati Medical Center, Ohio 45267.
Am J Physiol. 1993 Jun;264(6 Pt 2):H1781-7. doi: 10.1152/ajpheart.1993.264.6.H1781.
We studied seven open-chest anesthetized dogs to test the hypothesis that left atrial (LA) compliance is increased after pericardiectomy and to determine the effect of pericardiectomy on left atrial reservoir and conduit function. Two orthogonal sonomicrometer crystal pairs were used to estimate LA volume, and LA filling was assessed with a pulmonary vein (PV) flow probe. The left ventricular (LV) systolic (JFTI) and diastolic (KFTI) PV flow integrals were used as indexes of LA reservoir and conduit function, respectively. Diastolic LV transmitral flow was assessed with transesophageal Doppler echocardiography. Data were acquired over a wide range of intracardiac pressures and volumes obtained by intravenous hetastarch infusion both before and after pericardiectomy. The mean dynamic stiffness constant of the LA diastolic pressure-volume relation was significantly greater before pericardiectomy than afterwards (0.15 +/- 0.04 vs. 0.08 +/- 0.03 ml-1, P < 0.05). Data were analyzed before and after pericardiectomy at three matched levels of left atrial pressure (LAP; 7, 13, and 20 mmHg). The J-to-KFTI ratio increased significantly with volume infusion and was significantly less after pericardiectomy than before (1.2 +/- 0.7 vs. 1.2 +/- 0.6, 1.8 +/- 0.6 vs. 2.2 +/- 0.9, and 2.0 +/- 0.8 vs. 2.6 +/- 0.9 at low, mid, and high levels of LAP, respectively; P < 0.05 at mid and high levels of LAP). Peak early transmitral velocity increased with both volume infusion and pericardiectomy. We conclude that pericardiectomy increases LA compliance and early LV filling rate and is accompanied by a relatively greater augmentation in conduit than reservoir function of the left atrium.
我们研究了七只开胸麻醉犬，以检验心包切除术后左心房（LA）顺应性增加的假说，并确定心包切除术对左心房储器和管道功能的影响。使用两对正交的超声测微晶体来估计左心房容积，并用肺静脉（PV）血流探头评估左心房充盈情况。左心室（LV）收缩期（JFTI）和舒张期（KFTI）肺静脉血流积分分别用作左心房储器和管道功能的指标。经食管多普勒超声心动图评估舒张期左心室二尖瓣血流。在静脉输注羟乙基淀粉前后，在广泛的心内压力和容积范围内采集数据，这些压力和容积是通过静脉输注羟乙基淀粉获得的。心包切除术前左心房舒张压-容积关系的平均动态刚度常数显著大于术后（0.15±0.04对0.08±0.03 ml-1，P<0.05）。在三个匹配的左心房压力（LAP；7、13和20 mmHg）水平上分析心包切除术前和术后的数据。J-to-KFTI比值随容量输注显著增加，心包切除术后显著低于术前（低、中、高水平LAP时分别为1.2±0.7对1.2±0.6、1.8±0.6对2.2±0.9、2.0±0.8对2.6±0.9；中、高水平LAP时P<0.05）。早期二尖瓣峰值流速随容量输注和心包切除术均增加。我们得出结论，心包切除术增加了左心房顺应性和左心室早期充盈率，并且左心房管道功能的增强相对大于储器功能。
