TY - JOUR
T1 - Revisiting methods for assessing and comparing left ventricular diastolic stiffness
T2 - Impact of relaxation, external forces, hypertrophy, and comparators
AU - Jaber, Wissam A.
AU - Lam, Carolyn S.P.
AU - Meyer, Donna M.
AU - Redfield, Margaret M.
PY - 2007/11/1
Y1 - 2007/11/1
N2 - Understanding diastolic function mandates feasible and accurate methods to construct and compare the diastolic pressure (P)-volume (V) relationship (PVR). This study compared the relaxation-corrected single beat (RC-SB) to the multiple-beat (MB) (vena cava occlusion) method for constructing the diastolic PVR in 26 young normal or old hypertensive dogs before and after increases in afterload (phenylephrine) or acute volume expansion in the presence (n = 14) or absence (n = 12) of the pericardium. The PVR data were fit to P = αe β·V. Derived stiffness indexes compared included the stiffness coefficient (β), curve-fitting constant (α), and the end-diastolic volume (EDV) at 10, 20, or 30 mmHg [EDVx = ln(P x/α)/β] to account for covariance in α and β. In pericardium-intact young normal and old hypertensive dogs studied over varying afterloads, the MB and RC-SB PVR appeared identical. The β (r = 0.62) and α (r = 0.69) derived from the RC-SB vs. MB PVR showed moderate correlation but poor agreement. In contrast, the EDV10-30 derived from RC-SB vs. MB PVR showed excellent correlation (r = 0.97) and agreement. The uncorrected SB method underestimated stiffness. As expected, after acute volume expansion, the RC-SB PVR was shifted upward from the MB PVR (decreased EDV 10-30; P < 0.05) in the pericardium-intact but not pericardium-absent dogs. The RC-SB method can substitute for the MB technique in construction of PVR in the absence of acute volume expansion. The concordance between these two methods was poorly reflected by comparing the derived α and β but apparent when using EDV10-30, which provides information regarding the position of the PVR in a single number.
AB - Understanding diastolic function mandates feasible and accurate methods to construct and compare the diastolic pressure (P)-volume (V) relationship (PVR). This study compared the relaxation-corrected single beat (RC-SB) to the multiple-beat (MB) (vena cava occlusion) method for constructing the diastolic PVR in 26 young normal or old hypertensive dogs before and after increases in afterload (phenylephrine) or acute volume expansion in the presence (n = 14) or absence (n = 12) of the pericardium. The PVR data were fit to P = αe β·V. Derived stiffness indexes compared included the stiffness coefficient (β), curve-fitting constant (α), and the end-diastolic volume (EDV) at 10, 20, or 30 mmHg [EDVx = ln(P x/α)/β] to account for covariance in α and β. In pericardium-intact young normal and old hypertensive dogs studied over varying afterloads, the MB and RC-SB PVR appeared identical. The β (r = 0.62) and α (r = 0.69) derived from the RC-SB vs. MB PVR showed moderate correlation but poor agreement. In contrast, the EDV10-30 derived from RC-SB vs. MB PVR showed excellent correlation (r = 0.97) and agreement. The uncorrected SB method underestimated stiffness. As expected, after acute volume expansion, the RC-SB PVR was shifted upward from the MB PVR (decreased EDV 10-30; P < 0.05) in the pericardium-intact but not pericardium-absent dogs. The RC-SB method can substitute for the MB technique in construction of PVR in the absence of acute volume expansion. The concordance between these two methods was poorly reflected by comparing the derived α and β but apparent when using EDV10-30, which provides information regarding the position of the PVR in a single number.
KW - Heart failure
KW - Hemodynamics
KW - Methods
KW - Pericardium
UR - http://www.scopus.com/inward/record.url?scp=36148955065&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=36148955065&partnerID=8YFLogxK
U2 - 10.1152/ajpheart.00645.2007
DO - 10.1152/ajpheart.00645.2007
M3 - Article
C2 - 17693544
AN - SCOPUS:36148955065
VL - 293
SP - H2738-H2746
JO - American Journal of Physiology
JF - American Journal of Physiology
SN - 0363-6135
IS - 5
ER -