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

This Article Full Text (PDF) 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 Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Starling, M. R. Articles by Blumhardt, R. Search for Related Content PubMed PubMed Citation Articles by Starling, M. R. Articles by Blumhardt, R.

Assessment of the Radionuclide Angiographic Left Ventricular Maximum Time-Varying Elastance Calculation in Man

University of Michigan and VA Medical Centers, Ann Arbor, Michigan
University of Texas Health Science Center, San Antonio, Texas

Correspondence: For reprints contact: Mark R. Starling, MD, University of Michigan, Dept. of Internal Medicine, Div. of Cardiology, Veterans Administration Medical Center, 2215 Fuller Rd., Ann Arbor,MI 48105.

ABSTRACT

This investigation was designed to determine whether left ventricular (LV) maximum time varying elastance (E_max) calculations obtained using equilibrium radionuclide angiography (RNA) were comparable to those obtained using biplane contrast cineangiography (CINE), and whether simple, indirect P-V relations might provide reasonable, alternative estimates of E_max. Accordingly, we studied 19 patients with simultaneous high-fidelity micromanometer LV and fluid brachial artery (Ba) pressure recordings, CINE, and RNA under control conditions and during methoxamine and nitroprusside infusions. E_max was defined for CINE and RNA as the maximum slope of the linear relation of isochronal, instantaneous P-V data points obtained from each of the three loading conditions. The indirect P-V relations were similarly obtained from Ba peak (P) pressure versus minimum RNA LV volume (BaP/minV) and Ba dicrotic notch (di) pressure versus minimum RNA LV volume(Badi/minV) data points. The mean heart rates and LV(+)dP/dtmax values were minimally altered during the three loading conditions. The isochronal E_max values ranged from 1.40 to 6.73 mmHg/ml (mean 4.13 ± 1.99 s.d. mmHg/ml) for CINE and from 1.48 to 7.25 (mean 4.35 ± 1.81 mmHg/ml) for RNA (p= N.S.). Similarly, the unstressed volumes ranged from –10 to 80 ml (mean 30 ± 23 ml) for CINE and from –8 to 77 ml (29 ± 21 ml) for RNA (p=N.S.). The individual, isochronal E_max values by RNA correlated with those by CINE (r=0.86). In 14 of the 19 patients, the BaP/minV and Badi/ minV relations correlated with the isochronal E_max values calculated by RNA (r=0.83 and 0.82, respectively), and these relations also correlated with the E_max values calculated by CINE (r=0.82 and 0.78, respectively). The slope and V₀ values for the BaP/minV and Badi/minV relations underestimated those for E_max by RNA and CINE(p<0.01 and p<0.05, respectively, for both). Thus, the isochronal E_max values calculated using RNA are comparable to those obtained using CINE in man. Moreover, indirect P-V relations underestimate these E_max values, but they are linearly related with the isochronal E_max values calculated by RNA and CINE. Consequently, these indirect P-V relations may provide a more simple, alternative estimate of LV contractile function in man.

FOOTNOTES

This work was presented in part at the American Heart Association 58th Annual Scientific Sessions, Washington, D.C., November, 1985.

This article has been cited by other articles:

				M. R. Starling Effects of Valve Surgery on Left Ventricular Contractile Function in Patients With Long-term Mitral Regurgitation Circulation, August 15, 1995; 92(4): 811 - 818. [Abstract] [Full Text]