HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to Personal Folders Download to citation manager Permission Requests Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Feneley, M. P. Search for Related Content PubMed Articles by Feneley, M. P. Related Collections Related Article

Ann Thorac Surg 1996;61:1387-1388
© 1996 The Society of Thoracic Surgeons

---

Invited Commentary

Invited Commentary

Department of Cardiology, St. Vincent's Hospital Sydney Limited, Victoria St, Darlinghurst, Sydney NSW 2010, Australia

See also page 1381.

The poor correlation between right ventricular (RV) stroke volume and septal-free wall diameter shortening demonstrated by Nicolosi and associates is consistent with previous evidence that the latter is a poor index of volume change due to simultaneous changes in interventricular septal position when the volumes of both ventricles are changing [1]. For the same reason, however, it has been demonstrated that although the relationship between RV volume and free wall segment length is indeed linear at any given left ventricular volume, the position of this linear relationship in the volume--dimension plane shifts with changes in left ventricular volume [1]. Consequently, the position of the linear relationship between RV stroke volume and free wall segment shortening demonstrated by biventricular preload reduction in the study by Nicolosi and associates might shift significantly whenever biventricular geometry is altered, as occurs, for example, with RV volume or pressure overload. Similarly, derived indexes of contractility, such as the regional preload recruitable stroke work relationship, would be expected to remain linear but shift position with changes in the relative size and geometry of the two ventricles. It was precisely this problem of the dependence of RV regional segment measurements on biventricular geometric interactions that the ellipsoidal shell subtraction model was designed to overcome [1].

Similar concerns may be applicable to the conductance catheter volume measurements. Significant changes in biventricular geometry would be expected to change the relationship between the conductance catheter signal and RV volume. In addition, as Nicolosi and associates noted, the preferred method of placing the conductance catheter retrograde via the pulmonary artery is a limitation in chronic experiments.

Although the findings of Nicolosi and associates are valuable in furthering our methodologic approaches to the assessment of RV contractile function, considerable caution should be exercised in extrapolating these findings beyond the limited physiologic interventions examined. In particular, further experiments will be required to examine the applicability of these findings to situations of acute and chronic RV volume and pressure overload.

Reference

1. Feneley MP, Elbeery JR, Gaynor W, Gall SA Jr, Davis JW, Rankin JS. Ellipsoidal shell subtraction model of right ventricular volume: comparison with regional free wall dimensions as indexes of right ventricular function. Circ Res 1990;67:1427–36.

This Article Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to Personal Folders Download to citation manager Permission Requests Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Feneley, M. P. Search for Related Content PubMed Articles by Feneley, M. P. Related Collections Related Article