Transmitral flow velocity-contour variation after premature ventricular contractions: a novel test of the load-independent index of diastolic filling.
The new echocardiography-based, load-independent index of diastolic filling (LIIDF) M was assessed using load-/shape-varying E-waves after premature ventricular contractions (PVCs). Twenty-six PVCs in 15 subjects from a preexisting simultaneous echocardiography-catheterization database were selected. Perturbed load-state beats, defined as the first two post-PVC E-waves, and steady-state E-waves, were subjected to conventional and model-based analysis. M, a dimensionless index, defined by the slope of the peak driving-force vs. peak (filling-opposing) resistive-force regression, was determined from steady-state E-waves alone, and from load-perturbed E-waves combined with a matched number of subsequent beats. Despite high degrees of E-wave shape variation, M derived from load-varying, perturbed beats and M derived from steady-state beats alone were indistinguishable. Because the peak driving-force vs. peak resistive-force relation determining M remains highly linear in the extended E-wave shape and load variation regime observed, we conclude that M is a robust LIIDF.
Boskovski
Marko T
MT
Department of Physics, Washington University School of Arts and Sciences, St. Louis, MO, USA.
Shmuylovich
Leonid
L
Kovács
Sándor J
SJ
D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity; D003971:Diastole; D015150:Echocardiography, Doppler / Q000379:methods; D006439:Hemodynamics; D006801:Humans; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008955:Models, Cardiovascular; D016277:Ventricular Function, Left; D018879:Ventricular Premature Complexes / Q000000981:diagnostic imaging / Q000503:physiopathology*