左心房舒张和左心室收缩功能决定左心房的储血功能。

Left atrial relaxation and left ventricular systolic function determine left atrial reservoir function.

作者信息

Barbier P, Solomon S B, Schiller N B, Glantz S A

机构信息

Cardiovascular Research Institute, Department of Medicine, University of California, San Francisco, USA.

出版信息

Circulation. 1999 Jul 27;100(4):427-36. doi: 10.1161/01.cir.100.4.427.

DOI:10.1161/01.cir.100.4.427

PMID:10421605

Abstract

BACKGROUND

Determinants of left atrial (LA) reservoir function and its influence on left ventricular (LV) function have not been quantified.

METHODS AND RESULTS

In an open-pericardium, paced (70 and 90 bpm) pig model of LV regional ischemia (left anterior descending coronary constriction), with high-fidelity LV, LA, and RV pressure recordings, we obtained the LA area with 2D automated border detection echocardiography, LA pressure-area loops, and Doppler transmitral flow. We calculated LV tau, LA relaxation (a-x pressure difference divided by time, normalized by a pressure), and stiffness (slope between x and v pressure points of v loop). Determinants of total LA reservoir (maximum-minimum area, cm(2)) were identified by multiple regression analysis. Different mean rates of LA area increase identified 2 consecutive (early rapid and late slow) reservoir phases. During ischemia, LV long-axis shortening (LAS, LV base systolic descent) and LA reservoir area change decreased (7.3+/-0.3 [SEM] versus 5.6+/-0.3 cm(2), P<0.001) and LA stiffness increased (1.6+/-0.3 versus 3.1+/-0.3 mm Hg/cm(2), P=0.009). Early reservoir area change depended on LA mean ejection rate (LA area at ECG P wave minus minimum area divided by time; multiple regression coefficient=0.9; P<0.001) and relaxation (coefficient=4.9 cm(2)xms/s; P<0.001). Late reservoir area change depended on LAS (coefficient=8 cm/s; P<0.001). Total reservoir filling depended on LA stiffness (coefficient=-0.31 cm(4)/mm Hg; P=0. 001) and cardiac output (coefficient=0.001 cm(2)xmin/L; P=0.002). The strongest predictor of cardiac output was LA reservoir filling (coefficient=301 L/minxcm(2); P<0.001). The v loop area was determined by cardiac output, LV ejection time, tau, and early transmitral flow.

CONCLUSIONS

Two (early and late) reservoir phases are determined by LA contraction and relaxation and LV base descent. Acute LV regional ischemia increases LA stiffness and impairs LA reservoir function by reducing LV base descent.

摘要

背景

左心房（LA）储器功能的决定因素及其对左心室（LV）功能的影响尚未得到量化。

方法与结果

在一个开胸、起搏（70和90次/分钟）的猪左心室局部缺血（左前降支冠状动脉缩窄）模型中，通过高保真记录左心室、左心房和右心室压力，我们利用二维自动边界检测超声心动图获取左心房面积、左心房压力-面积环以及二尖瓣血流多普勒。我们计算了左心室时间常数、左心房松弛（a-x压差除以时间，并通过压力进行归一化）和僵硬度（v环x和v压力点之间的斜率）。通过多元回归分析确定了总左心房储器（最大-最小面积，cm²）的决定因素。不同的左心房面积增加平均速率确定了两个连续的（早期快速和晚期缓慢）储器阶段。在缺血期间，左心室长轴缩短（LAS，左心室基部收缩期下降）和左心房储器面积变化减少（7.3±0.3[标准误]对5.6±0.3 cm²，P<0.001），左心房僵硬度增加（1.6±0.3对3.1±0.3 mmHg/cm²，P = 0.009）。早期储器面积变化取决于左心房平均射血速率（心电图P波时的左心房面积减去最小面积除以时间；多元回归系数 = 0.9；P<0.001）和松弛（系数 = 4.9 cm²×ms/s；P<0.001）。晚期储器面积变化取决于LAS（系数 = 8 cm/s；P<0.001）。总储器充盈取决于左心房僵硬度（系数 = -0.31 cm⁴/mmHg；P = 0.001）和心输出量（系数 = 0.001 cm²×min/L；P = 0.002）。心输出量的最强预测因子是左心房储器充盈（系数 = 301 L/min×cm²；P<0.001）。v环面积由心输出量、左心室射血时间、时间常数和早期二尖瓣血流决定。