Outcomes of High Power Application in Catheter Ablation of Paroxysmal Atrial Fibrillation Guided by Unipolar Signal Modification.

Outcomes of High Power Application in Catheter Ablation of Paroxysmal Atrial Fibrillation Guided by Unipolar Signal Modification.

Outcomes of High Power Application in Catheter Ablation of Paroxysmal Atrial Fibrillation Guided by Unipolar Signal Modification.

Pulmonary vein isolation (PVI) is the cornerstone of catheter ablation procedures in patients with paroxysmal atrial fibrillation (PAF) [1]. However, the incidence of atrial fibrillation (AF) recurrence remains high [2], mostly due to pulmonary vein (PV) reconnection [1], emphasizing the formation of transmural lesions to achieve complete conduction block along the ablation lines [3]. Previous studies have shown that elimination of the negative component of the unipolar electrogram (UP-EGM) during radiofrequency applications reflects transmural lesions. The persistence of such a negative component consistently corresponds to non-trans mural lesions [4].

Pulmonary vein isolation (PVI) is the cornerstone of catheter ablation procedures in patients with paroxysmal atrial fibrillation (PAF) [1]. However, the incidence of atrial fibrillation (AF) recurrence remains high [2], mostly due to pulmonary vein (PV) reconnection [1], emphasizing the formation of transmural lesions to achieve complete conduction block along the ablation lines [3]. Previous studies have shown that elimination of the negative component of the unipolar electrogram (UP-EGM) during radiofrequency applications reflects transmural lesions. The persistence of such a negative component consistently corresponds to non-trans mural lesions [4]. The high-power short duration (HPSD) RF application applies to all RF energies delivered at more than 40 W [5]. Higher the power more is the resistive heating causing wider tissue injury [5]. The lesion size with HPSD is larger in width but lesser in depth compared to lower powers with longer duration [5]. In contrast, RF applications of lower power and longer duration result in larger dissipation of RF energies deep into the tissues due to conductive heating causing tissue destruction at greater depths [6]. Hence, there is a risk of collateral tissue damage [5]. HPSD ablation has been advocated as a means to minimize the risk of collateral organ damage as the lesions are smaller in depth. However, Maintaining a high power for a constant duration in the absence of a guide may not be the right strategy [5]. Unipolar waveform modification by complete elimination of the negative component may serve as a guide for HPSD ablation [5].

Radiofrequency delivery was performed in a point-by point fashion and continuously (an inter-lesion distance of 6 mm) with 50 W and 70 W and the ablation time for each point is limited to 7s and repeated if needed till the Unipolar signal modification turn to complete positive R wave.

Ablation success is defined as no recurrence with no anti-arrhythmic drugs by taking history of symptoms from the patient and by Holter 48 Hours.

Inclusion Criteria: Paroxysmal atrial fibrillation Exclusion Criteria: Age< 18 or > 80 years old, Atrium (LA) diameter > 50 mm, The presence of a mechanical mitral valve prosthesis, Left ventricular ejection fraction < 40%, Abnormal thyroid function, Contraindication to anticoagulant therapy, Current malignancy, Prior catheter or surgical AF ablation.

Kottmaier M, Popa M, Bourier F, Reents T, Cifuentes J, Semmler V, Telishevska M, Otgonbayar U, Koch-Buttner K, Lennerz C, Bartkowiak M, Kornmayer M, Rousseva E, Brkic A, Grebmer C, Kolb C, Hessling G, Deisenhofer I. Safety and outcome of very high-power short-duration ablation using 70 W for pulmonary vein isolation in patients with paroxysmal atrial fibrillation. Europace. 2020 Mar 1;22(3):388-393. doi: 10.1093/europace/euz342.