TY - JOUR
T1 - The Kinematic Filling Efficiency Index of the Left Ventricle
T2 - Contrasting Normal vs. Diabetic Physiology
AU - Zhang, Wei
AU - Chung, Charles S.
AU - Riordan, Matt M.
AU - Wu, Yue
AU - Shmuylovich, Leonid
AU - Kovács, Sándor J.
N1 - Funding Information:
This work was supported in part by the Heartland Affiliate of the American Heart Association (Dallas, TX), the Whitaker Foundation (Roslyn, VA), the National Institutes of Health (HL54179 and HL04023 Bethesda, MD), the Alan A. and Edith L. Wolff Charitable Trust (St Louis, MO) and the Barnes-Jewish Hospital Foundation. The authors thank Peggy Brown for expert echocardiographic data acquisition.
PY - 2007/6
Y1 - 2007/6
N2 - An index of filling efficiency incorporating stiffness and relaxation (S&R) parameters has not been derived or validated, although numerous studies have focused on the effects of altered relaxation or stiffness on early rapid filling and diastolic function. Previous studies show that S&R parameters can be obtained from early rapid filling (Doppler E-wave) via kinematic modeling. E-wave contours are governed by harmonic oscillatory motion modeled via the parameterized diastolic filling (PDF) formalism. The previously validated model determines three (unique) oscillator parameters from each E-wave having established physiological analogues: xo (load), c (relaxation/viscoelasticity) and k (chamber stiffness). We define the dimensionless, filling-volume-based kinematic filling efficiency index (KFEI) as the ratio of the velocity-time integral (VTI) of the actual clinical E-wave contour fit via PDF to the VTI of the PDF model-predicted ideal E-wave contour having the same xo and k, but with no resistance to filling (c = 0). To validate the new index, Doppler E-waves from 36 patients with normal ventricular function, 17 diabetic and 19 well-matched non-diabetic controls, were analyzed. E-wave parameters xo, c and k and KFEI were computed for each patient and compared. In concordance with prior human and animal studies in which c differentiated between normal and diabetic hearts, KFEI differentiated (p < 0.001) between nondiabetics (55.8% ± 3.3%) and diabetics (49.1% ± 3.3%). Thus, the new index introduces and validates the concept of filling efficiency, and, using diabetes as a working example, provides quantitative and mechanistic insight into how S&R affect ventricular filling efficiency. (E-mail: sjk@wuphys.wustl.edu).
AB - An index of filling efficiency incorporating stiffness and relaxation (S&R) parameters has not been derived or validated, although numerous studies have focused on the effects of altered relaxation or stiffness on early rapid filling and diastolic function. Previous studies show that S&R parameters can be obtained from early rapid filling (Doppler E-wave) via kinematic modeling. E-wave contours are governed by harmonic oscillatory motion modeled via the parameterized diastolic filling (PDF) formalism. The previously validated model determines three (unique) oscillator parameters from each E-wave having established physiological analogues: xo (load), c (relaxation/viscoelasticity) and k (chamber stiffness). We define the dimensionless, filling-volume-based kinematic filling efficiency index (KFEI) as the ratio of the velocity-time integral (VTI) of the actual clinical E-wave contour fit via PDF to the VTI of the PDF model-predicted ideal E-wave contour having the same xo and k, but with no resistance to filling (c = 0). To validate the new index, Doppler E-waves from 36 patients with normal ventricular function, 17 diabetic and 19 well-matched non-diabetic controls, were analyzed. E-wave parameters xo, c and k and KFEI were computed for each patient and compared. In concordance with prior human and animal studies in which c differentiated between normal and diabetic hearts, KFEI differentiated (p < 0.001) between nondiabetics (55.8% ± 3.3%) and diabetics (49.1% ± 3.3%). Thus, the new index introduces and validates the concept of filling efficiency, and, using diabetes as a working example, provides quantitative and mechanistic insight into how S&R affect ventricular filling efficiency. (E-mail: sjk@wuphys.wustl.edu).
KW - Diabetes
KW - Diastolic function
KW - Doppler echocardiography
KW - Efficiency
KW - Optimal filling
UR - http://www.scopus.com/inward/record.url?scp=34249295557&partnerID=8YFLogxK
U2 - 10.1016/j.ultrasmedbio.2006.11.003
DO - 10.1016/j.ultrasmedbio.2006.11.003
M3 - Article
C2 - 17478033
AN - SCOPUS:34249295557
VL - 33
SP - 842
EP - 850
JO - Ultrasound in Medicine and Biology
JF - Ultrasound in Medicine and Biology
SN - 0301-5629
IS - 6
ER -