In vivo and in vitro high density spatial and temporal resolution, visual and thermal mapping of radiofrequency ablation lesions utilising novel technologies to improve the success and safety of cardiac electrophysiology ablation procedures

Abstract

Radiofrequency ablation (RFA) has emerged as an important curative therapy for treatment of cardiac arrhythmias. However, significant deficiencies exist in achieving successful RFA outcomes while ensuring patients safety. Therefore, in this thesis we constructed an in vitro novel thermochromic phantom model to accurately assess RFA lesion size with higher spatial and temporal in order to achieve the optimal balance of delivering RF energy without causing overheating. Additionally, we ablated using an in vivo novel direct endocardial visualisation ablation catheter that preserves a clear field of view during delivery of RF energy at the desired target site. We developed a novel and practical electrogram-gated delivery of RFA such that it negated the effects cardiac contractions and respiratory motion related sliding catheter motion for creation of predictably consistent lesion depth irrespective of the degree of catheter motion occurring. Finally, we developed an in vitro novel acoustic hydrophone to detect impending steam pop during RFA such that it can be prevented in time to avoid potentially devastating clinical complications of cardiac perforation, tamponade and death. Ultimately, our goal was to enhance the proceduralist’s ability to achieve a desired balance between creating transmural lesion and preventing tissue overheating with steam pop and/or thrombus formation.