The effect of diastolic stiffness on ventricular function after partial ventriculectomy: a finite element simulation.
Partial ventriculectomy (PV) has been proposed by Batista and colleagues to improve cardiac function in patients with dilated cardiomyopathy (DCM); however, results have been mixed. We tested the hypothesis that preoperative diastolic function affects the stroke volume/end-diastolic pressure (Starling) relationship after PV. A previously described finite element simulation of DCM and PV was used. Diastole and end systole were represented by separate elastic finite element models with different unloaded shapes and nonlinear material properties. Left ventricular (LV) end-systolic elastance (E(ES)), diastolic compliance (DC), and Starling relationships were calculated. DC was varied by changing Ogden material property alpha(i) from 12 (compliant) to 20 (stiff). PV was simulated at 20% LV mass reduction. The slope of the Starling relationship increased from 1.82 to 1.21 as alpha(i) increased from 12 to 20. Partial ventriculectomy increased the Starling relationship in each case from 1.34 to 1.01 respectively. However, the net result in each case is a decrement in the Starling relationship with resection, and the smallest decrement was associated with the highest diastolic stiffness (alpha(i) = 20). Partial ventriculectomy depressed the Starling relationship for all values of diastolic compliance. It is expected that patients with a higher diastolic stiffness should do better.
Ratcliffe
M B
MB
Department of Surgery, School of Medicine of the University of California, San Francisco and the San Francisco Veterans Affairs Medical Center, 94121, USA.
Hong
J
J
Salahieh
A
A
Wallace
A W
AW
D002311:Cardiomyopathy, Dilated / Q000503:physiopathology / Q000601:surgery*; D003971:Diastole; D006352:Heart Ventricles / Q000601:surgery*; D006801:Humans; D016276:Ventricular Function