New technologies for catheter based treatment of paroxysmal atrial fibrillation – Everything under control?

We have been privileged in the past decades to witness the logic of scientific discovery bringing to light the mechanistic understanding and modern treatment of atrial fibrillation (AF). From being experimental in their early days, catheterbased techniques are now recommended as a Class 1 therapy for treatment of patients with symptomatic AF refractory to at least one membrane active antiarrhythmic medication [1]. However, while catheter ablation using radiofrequency (RF) energy is very efficient in suppression or even cure of many supraventricular and ventricular arrhythmias, it is far from reaching similar outcomes in more complex arrhythmias such as AF, as reflected in reported “re-do” AF ablation procedure rates of up to 50% [2,3]. Certainly, such frustrating numbers may raise the question whether we are doing the right thing, using the right tools and last but not least, understand what we are actually doing by using them. It is well known that reconnection of at least one pulmonary vein (PV) is present in nearly 100% of patients undergoing a “re-do” procedure due to arrhythmia recurrence, and therefore the creation of durable lesions is crucial for a permanent PV isolation (PVI) and freedomof arrhythmic events [4,5]. There is no doubt that successful arrhythmia treatment by RF ablation depends on a critical understanding of the biophysics of lesion creation and its control by e.g. titrating conventional parameters such as power, time and irrigation rate [6]. However, significant variability in lesion size may be responsible for both inefficacy as well as complications. Contact between electrode and tissue and, thus, catheter contact force (CF) has been shown to be a key parameter to control lesion size [7]. In this issue of the Indian Pacing and Electrophysiology Journal, Fichtner et al. (REF) report their results on a series of patients who underwent ipsilateral circumferential PVI for drug refractory paroxysmal AF either CF aided using the SmartTouch (N 1⁄4 30, ST group) or without CF monitoring but using the SurroundFlow catheter (N1⁄4 29, SF group) instead of the standard design irrigated catheter. The rationale behind the SF catheter is mainly a qualitatively improved widely distributed over the entire tip electrode surface catheter tip irrigation by compensating for changes in irrigation flow