Residual Stress Impairs Pump Function After Surgical Ventricular Remodeling: A Finite Element Analysis

Area of Science:

• Cardiovascular Surgery
• Biomedical Engineering
• Computational Biology

Background:

• The Dor procedure aims to improve left ventricular (LV) function after myocardial infarction.
• The precise impact of residual stress (RS) on LV myofiber stress (FS) and pump function post-Dor procedure remains unclear.

Purpose of the Study:

• To investigate the effect of residual stress (RS) on left ventricular (LV) myofiber stress (FS) and pump function following the Dor procedure.

Main Methods:

• Utilized finite element models of the LV based on sheep MRI data post-myocardial infarction.
• Simulated the Dor procedure using a virtual suture technique (VIRTUAL-DOR) with Dacron patches.
• Calculated RS, FS, LV volumes, and pump function during diastole and systole.

Main Results:

• VIRTUAL-DOR induced significant tensile RS in remote myocardium and compressive RS in the border zone.
• The presence of RS (VIRTUAL-DOR+RS) further reduced regional diastolic and systolic FS, particularly in the border zone.
• RS was associated with reduced LV volumes and a further decrease in overall pump function.

Conclusions:

• Residual stress post-Dor procedure is tensile in remote myocardium and compressive in the border zone.
• This RS contributes to reduced LV myofiber stress and volumes.
• The net effect of RS is a detrimental impact on left ventricular pump (Starling) function.