Clinical Experience with a Single Catheter for Mapping and Ablation of Pulmonary Vein Ostium

Efficacy of cryoballoon ablation in patients with paroxysmal atrial fibrillation without time to pulmonary vein isolation assessment

BACKGROUND

Real-time visualization of the electrical activity of the pulmonary veins (PV) is not always possible in the setting of atrial fibrillation (AF) cryoballoon ablation. We investigated the relation between the effective documentation of time to PV isolation and the clinical outcome in a cohort of patients with paroxysmal AF who underwent cryoballoon ablation.

METHODS

One thousand forty two consecutive patients were enrolled. An inner lumen mapping catheter was typically used to visualize real-time electrical activity inside the PVs.

RESULTS

Time to PV isolation was documented in all targeted PVs in 391 patients (Group 1), in 651 patients it was not possible to record PV potentials and assess time to PV isolation in at least one PV (Group 2). In Group 1 a longer procedure duration and ablation time were observed, while a longer fluoroscopy time was observed in Group 2. After a mean follow-up of 14 ± 11 months, 209/1042 (20%) patients had an atrial arrhythmia recurrence (20.2% in Group 1, 19.9% in Group 2, p = 0.25). Complications occurred in 54/1042 (5.2%) patients without any difference among the two study groups.

CONCLUSION

In our retrospective analysis, in about two thirds of patients undergoing cryoballoon ablation it was not possible to acutely assess time to PV isolation in all PVs. However, one-year freedom from clinically symptomatic atrial tachyarrhythmia was similar to that of patients in which time to PV isolation was documented in all targeted veins.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov (NCT01007474).

Pulmonary vein potential mapping in atrial fibrillation with high density and standard spiral (lasso) catheters: A comparative study

Background

The dominant single-shot procedure for Pulmonary Vein Isolation (PVI) is the Cryoballoon Ablation (CBA) technique using a spiral catheter (Achieve™, AC) for mapping and monitoring purposes. We hypothesized that Basket Catheters, such as the High Density Mesh Mapper (HDMM), with its high-density mapping properties, could detect Pulmonary Vein Potentials (PVPs) that the octapolar AC would not be able to identify.

Methods

Twenty-four patients (average age 61.8±10 years) with either paroxysmal or persistent atrial fibrillation (AF) (Paroxysmal AF or Persistent AF) were enrolled in the study. While the patients were in sinus rhythm, all pulmonary veins (PVs) were prospectively mapped both prior and subsequent to CBA with a 32-pole HDMM and an 8-pole AC. PVPs were recorded using both catheters, and their location was allocated to one of four PV quadrants. Then, the quadrant findings of the mapping catheters were compared.

Results

Mapping using the HDMM allowed for more precise identification of PVPs both before and after CBA compared to AC mapping. We identified an average of 83.6±4.8 PVPs in all four PVs (this means 20.9±10.5 PVPs /per single PV per patient [HDMM], 14.5±1.3 PVPs/in all four PVs and 3.6±2.7 PVPs /per single PV per patient [AC]) before ablation, thereby leading to a significant difference in the identification of PVPs per PV quadrant. Of 384 PV quadrants/24 patients analyzed, the HDMM identified PVPs in 279 and AC in only 192 quadrants (P<0.05).

Conclusion

High-density mapping with a Basket Catheter, such as the HDMM, detects PVPs that remain undetected when using the standard AC catheter in CBA procedures.

Effect of left atrial volume and pulmonary vein anatomy on outcome of nMARQ™ catheter ablation of paroxysmal atrial fibrillation

PURPOSE

Left atrial volume (LA) and pulmonary vein (PV) anatomy may potentially relate to technical challenges in achieving stable and effective catheter position in case of atrial fibrillation (AF) ablation by means of "one-shot" catheters. The aim of this study was to investigate whether LA volume and PV anatomy, evaluated by computed tomography (CT) or magnetic resonance (MR) prior to ablation, predict acute and midterm outcome of AF ablation by nMARQ™.

METHODS

We included 75 patients (mean age 58 ± 11 years, 67 % male) with symptomatic paroxysmal AF. All patients underwent CT/MR scanning prior to catheter ablation to evaluate LA volume and PV anatomy. All the patients underwent PV isolation by nMARQ™, an open-irrigated mapping and radiofrequency (RF) decapolar ablation catheter. Ablation was guided by electroanatomic mapping allowing RF energy delivery in the antral region of PVs from ten irrigated electrodes simultaneously.

RESULTS

Mean LA volume was 75 ± 40 ml. A normal anatomy (4 PVs) was documented in 40 (53 %) patients and abnormal anatomy (common truncus or accessory PVs) in 35 patients. Mean procedural and fluoroscopy times were 94 ± 55 and 8 ± 5 min, respectively, without significant differences among patients with normal or abnormal anatomy (92 ± 45 vs 95 ± 64 min, p = 0.85 and 6 ± 3 vs 8 ± 4 min, p = 0.65, respectively). Mean ablation time was 14 ± 3 min, and 99 % of the targeted veins were isolated with a mean of 23 ± 5 RF pulses per patient. After a mean follow-up of 17 ± 8 months, 23 (31 %) patients had an atrial arrhythmia recurrence. Neither LA volume nor PV anatomy was a predictor of outcome.

CONCLUSIONS

LA volume and PV anatomy did not affect procedural data and outcome in patients who underwent PV isolation by an open-irrigated mapping and RF decapolar ablation catheter.

Interventional treatment of atrial fibrillation - contemporary methods and perspectives

Atrial fibrillation (AF) is estimated to affect nearly 3 million people around the world. It is the most common arrhythmia and its incidence increases with age. Catheter ablation is an interventional procedure performed to reduce the patient's AF burden when pharmacotherapy did not succeed in relieving the patient's symptoms. The ablation is most effective in paroxysmal AF; however, many techniques are being developed to make this procedure more eligible for patients with persistent arrhythmia. The most common AF ablation technique involves separating electric activity of the pulmonary veins from the left atrium. Over recent years, many novel and promising techniques were developed (e.g., balloon cryoablation, circular catheter ablation, laser ablation, robotic navigation, etc.), which may further improve AF ablation efficacy.

Electronic sensor and actuator webs for large-area complex geometry cardiac mapping and therapy

Curved surfaces, complex geometries, and time-dynamic deformations of the heart create challenges in establishing intimate, nonconstraining interfaces between cardiac structures and medical devices or surgical tools, particularly over large areas. We constructed large area designs for diagnostic and therapeutic stretchable sensor and actuator webs that conformally wrap the epicardium, establishing robust contact without sutures, mechanical fixtures, tapes, or surgical adhesives. These multifunctional web devices exploit open, mesh layouts and mount on thin, bio-resorbable sheets of silk to facilitate handling in a way that yields, after dissolution, exceptionally low mechanical moduli and thicknesses. In vivo studies in rabbit and pig animal models demonstrate the effectiveness of these device webs for measuring and spatially mapping temperature, electrophysiological signals, strain, and physical contact in sheet and balloon-based systems that also have the potential to deliver energy to perform localized tissue ablation.

2012 HRS/EHRA/ECAS expert consensus statement on catheter and surgical ablation of atrial fibrillation: recommendations for patient selection, procedural techniques, patient management and follow-up, definitions, endpoints, and research trial design

This is a report of the Heart Rhythm Society (HRS) Task Force on Catheter and Surgical Ablation of Atrial Fibrillation, developed in partnership with the European Heart Rhythm Association (EHRA), a registered branch of the European Society of Cardiology and the European Cardiac Arrhythmia Society (ECAS), and in collaboration with the American College of Cardiology (ACC), American Heart Association (AHA), the Asia Pacific Heart Rhythm Society (APHRS), and the Society of Thoracic Surgeons (STS). This is endorsed by the governing bodies of the ACC Foundation, the AHA, the ECAS, the EHRA, the STS, the APHRS, and the HRS.

[Pulmonary vein isolation with multipolar ablation catheters for the treatment of paroxysmal atrial fibrillation]

Atrial fibrillation (AFIB) is the most common atrial rhythm disease and is associated with an increased risk of thromboembolic and cardiac complications. Different therapies are used in clinical routine: frequency control with anticoagulants and rhythm control. In patients with paroxysmal AFIB but without structural heart disease, antiarrhythmic drug therapy was previously first priority; however, pulmonary vein catheter ablation is becoming more important. "Single tip" systems, ultrasound, and various balloon techniques have been used in clinical routine. New radiofrequency systems with multipolar radiofrequency ablation catheters, however, give hope for better outcomes with fewer intraprocedural complications, as well as shorter procedure and fluoroscopy times.