EJECTING ACTIVATION DIFFERS IN ENERGETICS FROM ORDINARY POSITIVE INOTROPISM IN THE CANINE LEFT-VENTRICLE

被引：1

作者：

YASUMURA, Y

NOZAWA, T

FUTAKI, S

TANAKA, N

SUGA, H

机构：

[1] Department of Cardiovascular Dynamics, National Cardiovascular Center Research Institute, Suita, Osaka, 565

来源：

HEART AND VESSELS | 1994年 / 9卷 / 03期

关键词：

SHORTENING ACTIVATION; DEACTIVATION; OXYGEN CONSUMPTION; PRESSURE-VOLUME AREA;

D O I：

10.1007/BF01745238

中图分类号：

R5 [内科学];

学科分类号：

1002 ; 100201 ;

摘要：

Ventricular ejection is known to have dual effects on the end-systolic pressure: the ejecting deactivation by a relatively large ejection against a low afterload versus the ejecting activation by a relatively small ejection against a high afterload. We studied how the increase in contractility index (Emax) by the ejecting activation would affect myocardial oxygen consumption (VO2). To this end, left ventricular steady-state ejecting contractions were produced with various stroke volumes from a fixed end-diastolic volume in an excised cross-circulated canine heart. The effect of the ejection-activated Emax on VO2 was assessed by the relation between VO2 and pressure-volume area (PVA). PVA is the total mechanical energy generated by ventricular contraction. In contrast to the elevation of the linear VO2-PVA relation in a parallel manner with an enhanced Emax by ordinary positive inotropic agents such as catecholamines and calcium, the ejection-activated Emax did not elevate the VO2-PVA relation. This result indicates that the ejecting activation enhances Emax in an energetically different manner from ordinary positive inotropism in the canine left ventricle.

引用

页码：129 / 139

页数：11

共 29 条

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