Advances in Imaging for Atrial Fibrillation Ablation

Abstract

Over the last fifteen years, our understanding of the pathophysiology of atrial fibrillation (AF) has paved the way for ablation to be utilized as an effective treatment option. With the aim of gaining more detailed anatomical representation, advances have been made using various imaging modalities, both before and during the ablation procedure, in planning and execution. Options have flourished from procedural fluoroscopy, electroanatomic mapping systems, preprocedural computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, and combinations of these technologies. Exciting work is underway in an effort to allow the electrophysiologist to assess scar formation in real time. One advantage would be to lessen the learning curve for what are very complex procedures. The hope of these developments is to improve the likelihood of a successful ablation procedure and to allow more patients access to this treatment.

Fiber-optic catheter-based polarization-sensitive OCT for radio-frequency ablation monitoring

“…Catheter-based radio-frequency ablation (RFA) through percutaneous access is commonly practiced in interventional electrophysiology therapeutic procedures to treat cardiac arrhythmias that are not responsive to anti-arrhythmia drugs [2]. RFA creates a thermal lesion to destroy tissue involved in abnormal electrical conduction in order to restore normal conduction patterns.…”

“…RFA creates a thermal lesion to destroy tissue involved in abnormal electrical conduction in order to restore normal conduction patterns. Currently, monitoring of the RFA lesion formation is accomplished only through indirect measures, such as tissue temperature, impedance, and electrograms [2]. Direct imaging feedback at the catheter tip may improve RFA procedures by confirming catheter contact, identifying tissue structures, and confirming ablation lesion formation.…”

Atrio-oesophageal fistula after transcatheter radiofrequency ablation

“…Up to 60 000 ablations are performed in Europe each year,1 and common complications are recognised (box 1).

Common complications of TcRFA

Complications following transcatheter radiofrequency ablation

Failure of the procedure;

Pain/bleeding at catheter insertion point;

Pulmonary vein stenosis;

Cardiac tamponade;

Stroke.

…”

The Future of Cardiac Mapping

“…A common characteristic of all X-ray images is that the soft tissue of the myocardium cannot be visualized (Figure 1), nevertheless, the walls of the left atrium can be indirectly assessed by bolus injection of contrast, which can be augmented by manoeuvres that minimize atrial emptying such as adenosine or rapid ventricular pacing. However, the major disadvantage of using X-ray fluoroscopy as the sole imaging modality is that all images obtained are two-dimensional representations of three-dimensional structures (D'Silva & Wright, 2011). …”