Analysis of the Effects of Alcohol Ablation on the Mechanical Properties of Heart Tissue

Heart diseases are the leading cause of death and many techniques have been developed to treat them. One such disease affecting the heart’s mitral valve, severe mitral regurgitation, affects over five million adults in the US and can be fatal. To combat diseases like this, transcatheter mitral valve replacement (TMVR) emerged as a less invasive alternative to surgical mitral valve repair or replacement. However, TMVR can cause life-threatening complications such as the obstruction of blood flow in the aorta, the main artery in the human body that is responsible for carrying oxygen-rich blood from the heart to the rest of the body. To reduce risk and prevent this obstruction from occurring, alcohol septal ablation (ASA) is often performed on TMVR patients, though the effects of ASA on the performance of the heart have not been studied. Therefore, the goal of this project was to analyze the effects of ASA on the mechanical properties of the septal region of the heart.

To achieve this, square samples of tissue from the septal region of swine hearts were stretched to 20% displacement on a biaxial stretcher before and after experiencing either a three- or five-minute period of ASA. Data indicated that the mean force required to achieve this displacement in the tissue increased significantly after ASA, with the percent differences in the mean forces required in pre- and post-ASA being 62.45% and 87.12% in the main fiber direction and 49.47% and 75.42% in the cross-fiber direction for three-minute ASA and five-minute ASA, respectively. This suggests that tissue stiffens following ASA, with the amount of stiffness increasing with increasing periods of ASA. The degree of stiffness found indicates that regions of the heart affected by ASA will not contract normally, which can lead to patients experiencing a reduced cardiac output following the ASA procedure.