Session 2H: T-Tubule Loss Causes Greater Distances for EC Coupling

Heart failure (HF) affects 6 million adults in the United States, with 500,000 new cases reported each year. Nonetheless, the cellular mechanisms that lead to the progression of HF are poorly understood, resulting in difficulties in treatment and prevention. Recent findings suggest that HF cells have a lower T-tubule density than normal cells, which contributes to poor EC coupling. The purpose of the investigation is to measure the changes in T-Tubule density in the onset of HF in atrial and ventricular cells. To measure T-Tubule density, atrial and ventricular cells of HF and normal dog hearts were analyzed using AutoTT software, in which the T-Tubule and cytosolic areas were quantified in the 2D images. Another analysis routine was used to further quantify T-Tubule loss using Nearest Neighbor software which measured the distance from any point to the nearest T-Tubule or cell membrane. The results showed that T-Tubule loss in HF causes greater distances between the calcium trigger and calcium release independent of cell size. This affects EC coupling by increasing the distance calcium must travel to induce cellular contraction