Deciphering the fine structure of atrial cells in healthy hearts, and in those with heart failure, for clues to atrial fibrillation

Understanding the structural and functional properties of atrial Ca2+ release sites, how they are remodelled in heart failure and the consequences for atrial function and arrhythmias

Atrial fibrillation (AF) is the most common form of irregular heart rhythm, and people with heart failure are more at risk of the condition. AF affects the atria - the top two heart chambers – where disturbed electrical signals prevent rhythmic contraction. This stops blood from passing efficiently out of the atria; instead it can pool and clot, which may lead to a stroke if the clot travels to the brain Contraction of heart muscle relies on the flow of calcium in and out of heart muscle cells. But the pattern of calcium release in atrial cells is very different from cells in the other heart chambers and is poorly understood. In this project, Dr Katherine Dibb and her team will use super resolution microscopes to determine how the specific architecture of atrial cells influences calcium flow. They will also carry out the same investigations in cells affected by heart failure, which may increase our understanding of why AF is more prevalent in people with this condition. Dr Dibb and her team believe that a fundamental understanding of heart contraction will take us closer to finding better treatments that will save lives.