Mapping the 3-dimensional structure of the human atria

2020 Health Professional Scholarship

Years funded: 2021-2023

Our proposed projects are aimed at characterising the way small chambers of the heart (the atria) are activated in patients with atrial fibrillation (AF). AF is the most common sustained atrial arrhythmia. Australian data estimated the number of AF sufferers >55 years of age to be 0.33 million with that number doubling to 0.66 million in 20 years time. AF is associated with complications of stroke, heart failure, and recurrent hospitalisations, which represent a significant socioeconomical burden on the healthcare system. Cather ablation is highly effective in paroxysmal AF (AF of shorter duration).

However, in AF of longer duration (non paroxysmal AF), results are less satisfactory. The mechanisms behind this poor response remain elusive and poorly understood. Recently, studies have hypothesised that AF activates the small chamber of the heart in a complex 3-dimensional way which if proven, will have implications on our understanding of AF mechanisms. Project 1 is a prospective study where patients with AF undergoing open heart surgery will have electrical signals from the inside and outside surfaces of the right atrium (the right small chamber of the heart) recorded using 2 mapping catheters for analysis of how the right atrium is activated in patients with AF. In addition, a tissue sample of the right atrium will be taken for analysis under the microscope to determine whether abnormal electrical activations correspond to abnormal tissue composition.

Project 2 is a prospective study where patients with AF undergoing catheter ablation for AF will have electrical signals from the area the separates the 2 small chambers of the heart (the inter atrial septum) collected for analysis of abnormal electrical activation. The results from our projects will advance our understanding of AF mechanisms and pave the way towards more successful ablation strategies to halt the progression of non-paroxysmal AF.