| dc.description.abstract | Atrial fibrillation (AF), synchronized atrial contraction in lost decreasing cardiac output and increasing atrial pressure and is thought to be associated with low left atrial (LA) compliance. Management of AF is through the permanent destruction of abnormal cardiac tissue responsible for cardiac arrhythmogenesis, whilst avoiding collateral tissue injury forms the cornerstone of catheter ablation therapy. Although the acceptance and performance of catheter ablation has increased worldwide, there is still a relatively low success rate of 70% for first-time AF ablation. Atrial compliance allows the atria to react in response to homeostatic change as well as atrial fibrillation being associated with low compliance (so is ablation) with more extensive ablations with more touches though to reduce LA compliance. It is unclear what clinical implications LA compliance has on patients who underwent radiofrequency catheter ablation, although several attempts have been made to measure compliance of the left atrium each of these have had their limitations. The hypothesis of this thesis was that AF, a multifactorial disease associated with degenerative disease, may contribute to reduced LA compliance. There have been several ways to estimate compliance in the past each with their limitations. This thesis aims to determine a suitable measure of compliance from data collected from patients with both paroxysmal and persistent atrial fibrillation as standard as part of the radiofrequency ablation procedure. Once a suitable measure for compliance was determined, to preliminary test this measure in a small pilot study to determine factors that could reduce compliance. Finally, in the same cohort of patients begin to explore the impact of fibrosis through voltage on the measure of compliance calculated. Additionally, an attempt will be made to develop a mechanical tissue measurement rig in order to recreate force measurements used as part of the compliance measure ex-vivo, for an in-depth look at the variability in mechanical properties of left atrial tissue in porcine atria. | en_US |
