Ablation of Focal Activation in Atrial Fibrillation

Summary

Recurrent focal electrical activation (or ectopy) superseding sinus activation is the only mechanism proven to drive paroxysmal atrial fibrillation (AF). However, it has not been possible to show similar focal drivers during AF, owing to the limitations of mapping in persistent AF. RETRO-Mapping has been developed as a method to generate activation maps during AF to test the hypothesis that persistent AF is also maintained by focal drivers. RETRO-Mapping is able to locate sites of focal activation that were isolated, intermittent, or recurrent during persistent AF. However, a 30-second segment of AF can have approximately 150 wavefronts in a small area of myocardium. Screening for focal activation and manually validating these prior to ablation was not feasible using current commercial systems. RETRO-Mapping can automatically detect focal activation and a recording system that enables the intracardiac signals to be directly analysed by the RETRO-Mapping software. This will allow RETRO-Mapping to build a detailed classification of focal activation types and study the impact of ablation of these sites on the AF cycle length, to address the hypothesis that persistent AF is maintained by focal drivers.

Eligibility

Inclusion Criteria:

* Persistent atrial fibrillation with clinical indication for catheter ablation
* Clinically suitable candidate for catheter ablation
* Signed informed consent

Exclusion Criteria:

* Previous atrial fibrillation or other catheter ablation procedure
* Clinical contraindication to catheter ablation or general anaesthetic, including history of adverse reaction to contrast media, or presence of intracardiac thrombus, or inadequate anticoagulation in the preceding 6 weeks
* Valvular disease graded moderate or greater, or presence of a prosthetic valve
* Moderate-to-severe heart failure, defined as left ventricular ejection fraction \<35% and/or New York Heart Association class III-IV
* Any form of cardiomyopathy
* Active infection or fever
* Severe cerebrovascular disease
* Active gastrointestinal bleeding
* Bleeding or clotting disorders, clinically high bleeding risk, or clinical contraindication to receiving heparin
* Baseline serum creatinine \>200umol/L
* Currently receiving or at risk of requiring renal replacement therapy
* Uncontrolled diabetes (HbA1c ≥73mmol/mol or HbA1c ≤64mmol/mol and fasting blood glucose ≥9.2mmol/L)
* Malignancy necessitating therapy
* Life expectancy shorter than the duration of the trial
* Pregnancy, or childbearing potential and not using a highly effective method of contraception
* Inability to provide informed consent to participate in the trial

Conditions6

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