使用超声心动图和电导技术评估猪的右心室功能。

Assessment of right ventricular function in swine using sonomicrometry and conductance.

作者信息

Nicolosi A C, Hettrick D A, Warltier D C

机构信息

Department of Cardiothoracic Surgery, Medical College of Wisconsin, Milwaukee 53226, USA.

出版信息

Ann Thorac Surg. 1996 May;61(5):1381-7; discussion 1387-8. doi: 10.1016/0003-4975(96)00106-3.

DOI:10.1016/0003-4975(96)00106-3

PMID:8633946

Abstract

BACKGROUND

Assessment of right ventricular (RV) pressure-volume relations has been hampered by difficulty measuring instantaneous, absolute RV volume. Accordingly, several methods were tested for their ability to reflect relative RV volume and to determine changes in RV contractile state.

METHODS

Swine (46 to 54 kg; n = 7) were anesthetized and instrumented to measure instantaneous RV pressure, septal-to-RV free wall diameter (SFWD), RV free wall segment length (FWSL), RV volume via conductance (CV), and pulmonary artery flow, the integral of which was used as the standard for stroke volume. Flow-derived stroke volume was correlated with the systolic change in CV, FWSL, and SFWD in the steady state after incremental volume loading and on a beat-to-beat basis during transient inferior vena caval occlusion. Contractility was altered by calcium and pentobarbital and assessed by preload recruitable stroke work (PRSW).

RESULTS

Mean (+/- standard error of the mean) correlations (r) versus stroke volume during steady state conditions were 0.85 +/- 0.04 for FWSL, 0.83 +/- 0.04 for CV, and -0.04 +/- 0.24 for SFWD. Mean r values versus stroke volume during caval occlusions were 0.83 +/- 0.03 for FWSL, 0.85 +/- 0.04 for CV, and -0.03 +/- 0.31 for SFWD. Calcium increased mean PRSW slope compared with control using CV (20.3 +/- 2.6 versus 16.1 +/- 1.9 mm Hg; p < 0.05), and pentobarbital decreased mean PRSW slope compared with control using both CV and FWSL (11.3 +/- 1.0 versus 16.1 +/- 1.9 mm Hg, p < 0.05; and 11.9 +/- 2.1 versus 26.1 +/- 4.0 mm Hg, p < 0.05, respectively). There were no changes in PRSW slope with either calcium or pentobarbital using SFWD. The PRSW function was linear with both FWSL and CV but not with SFWD.

CONCLUSIONS

In the normal heart, both FWSL and CV, but not SFWD, accurately reflect relative instantaneous RV volume and are thus useful for determining RV contractility by pressure-volume (pressure-dimension) indices.

摘要

背景

右心室（RV）压力-容积关系的评估因难以测量瞬时、绝对的RV容积而受到阻碍。因此，对几种方法进行了测试，以评估它们反映相对RV容积以及确定RV收缩状态变化的能力。

方法

对体重46至54千克的猪（n = 7）进行麻醉并植入仪器，以测量瞬时RV压力、室间隔至RV游离壁直径（SFWD）、RV游离壁节段长度（FWSL）、通过电导法测量的RV容积（CV）以及肺动脉血流，其积分用作每搏输出量的标准。在递增容量负荷后的稳态下以及在下腔静脉短暂闭塞期间逐搏测量时，将血流衍生的每搏输出量与CV、FWSL和SFWD的收缩期变化进行相关性分析。通过钙和戊巴比妥改变收缩性，并通过预负荷可招募的每搏功（PRSW）进行评估。

结果

在稳态条件下，FWSL与每搏输出量的平均（±平均标准误差）相关性（r）为0.85±0.04，CV为0.83±0.04，SFWD为-0.04±0.24。在下腔静脉闭塞期间，FWSL与每搏输出量的平均r值为0.83±0.03，CV为0.85±0.04，SFWD为-0.03±0.31。与对照组相比，使用CV时钙增加了平均PRSW斜率（20.3±2.6对16.1±1.9毫米汞柱；p<0.05），使用CV和FWSL时戊巴比妥均降低了平均PRSW斜率（分别为11.3±1.0对16.1±1.9毫米汞柱，p<0.05；以及11.9±2.1对26.1±4.0毫米汞柱，p<0.05）。使用SFWD时，钙或戊巴比妥对PRSW斜率均无影响。PRSW函数与FWSL和CV均呈线性关系，但与SFWD不呈线性关系。