Gawne T J, Gray K S, Goldstein R E
Uniformed Services University of the Health Sciences, Department of Medicine, Bethesda, Maryland 20814.
J Appl Physiol (1985). 1987 Aug;63(2):872-6. doi: 10.1152/jappl.1987.63.2.872.
The measurement of left ventricular volume by the conductance-catheter technique has many advantages, but it is difficult to determine absolute volumes with this method. Current procedure requires that a bolus of concentrated hypertonic saline be injected to measure absolute volume. It also demands that the subject be in a steady state and that measurements only be made at discrete intervals. The saline bolus may affect the cardiovascular state of the subject. This paper describes a new technique for estimating absolute volume utilizing the conductance catheter that relies on the different frequency responses of blood and muscle. Good correlation between the salt-injection method and the dual-frequency method was found in nine closed-chest pigs anesthetized with pentobarbital sodium (r = 0.922). Further refinements may extend the utility of the dual-frequency approach.
采用电导导管技术测量左心室容积有诸多优点，但用此方法难以测定绝对容积。目前的操作流程要求注射一剂浓缩高渗盐水来测量绝对容积。它还要求受试者处于稳定状态，且只能在离散的时间间隔进行测量。注射盐水团可能会影响受试者的心血管状态。本文描述了一种利用电导导管估算绝对容积的新技术，该技术基于血液和肌肉不同的频率响应。在用戊巴比妥钠麻醉的9只开胸猪身上，发现盐注射法与双频法之间具有良好的相关性（r = 0.922）。进一步的改进可能会扩展双频方法的应用范围。
