Radmira Greenstein

Clinical significance of early recurrences of atrial fibrillation after pulmonary vein isolation

OBJECTIVES The purposes of this study were to describe the prevalence of early recurrences of atrial fibrillation (ERAF) that occur within two weeks after pulmonary vein (PV) isolation, and to determine whether ERAF is predictive of long-term outcome after PV isolation. BACKGROUND Atrial fibrillation (AF) sometimes recurs within days after PV isolation and may prompt an early repeat intervention. METHODS Segmental PV isolation was performed using radiofrequency energy in 110 consecutive patients (mean age 53 +/- 11 years) with paroxysmal (93 patients) or persistent (17 patients) AF. Three to four PVs were targeted for isolation in all patients. Pulmonary vein isolation was complete in 338 of the 358 PVs that were targeted (94%). RESULTS Early recurrences of AF occurred in 39 of 110 patients (35%) at a mean of 3.7 +/- 3.5 days after the procedure. The prevalence of ERAF was similar in patients with paroxysmal and persistent AF (33% and 47%, respectively, p = 0.4). Beyond the first two weeks, at 208 +/- 125 days of follow-up, 60 of the 71 patients without ERAF (85%) and 12 of the 39 patients with ERAF (31%) were free of recurrent AF in the absence of antiarrhythmic drug therapy (p < 0.001). CONCLUSIONS Early recurrences of AF occur in approximately 35% of patients within two weeks after isolation of three to four PVs, and are associated with a lower long-term success rate than in patients without ERAF. However, approximately 30% of patients with ERAF have no further symptomatic AF during long-term follow-up. Therefore, temporary antiarrhythmic drug therapy may be more appropriate than early repeat ablation in patients with ERAF.

Segmental Ostial Ablation to Isolate the Pulmonary Veins During Atrial Fibrillation Feasibility and Mechanistic Insights

Background—The purpose of this study was to determine the feasibility and mechanistic implications of segmental pulmonary vein (PV) ostial ablation during atrial fibrillation (AF). Methods and Results—Forty consecutive patients underwent PV isolation for AF. Among 125 PVs targeted for isolation, ablation was performed during AF in 70 veins and during sinus rhythm in 55 veins. A decapolar Lasso catheter was positioned near the ostium. During AF, ostial ablation was performed near the Lasso catheter electrodes that recorded a tachycardia with a cycle length shorter than in the adjacent left atrium. During sinus rhythm, ostial ablation was guided by PV potentials. Complete PV isolation was achieved in 70 PVs (100%) ablated during AF and in 53 PVs (96%) ablated during sinus rhythm (P =0.4). The mean durations of radiofrequency energy needed for isolation were 7.4±4.4 and 5.2±3.9 minutes during AF and sinus rhythm, respectively (P <0.01). Before ablation, an immediate recurrence of AF (IRAF), occurred after cardioversion in 18 of 40 patients, and IRAF was consistently abolished by PV isolation. The probability of AF termination during isolation of a PV was directly related to the extent of tachycardia in that vein. As more PVs were isolated, induction of persistent AF by rapid pacing became less likely. Conclusions—Segmental ostial ablation guided by PV tachycardia during AF is feasible and as efficacious as during sinus rhythm. The responses to cardioversion, ablation, and rapid pacing observed in this study imply that IRAF is triggered by the PVs and that PV tachycardias may play an important role in the perpetuation of AF.

Mechanistic Significance of Intermittent Pulmonary Vein Tachycardia in Patients with Atrial Fibrillation

Pulmonary Vein Tachycardia. Introduction: The significance of intermittent tachycardia within a pulmonary vein (PV) during an episode of atrial fibrillation (AF) is unclear. The aim of this study was to determine the role that intermittent PV tachycardias play in AF.

Differentiation of atrial and pulmonary Vein potentials recorded circumferentially within pulmonary veins

Pulmonary Vein Electrograms. Introduction: Accurate discrimination of atrial and pulmonary vein potentials recorded circumferentially within the pulmonary veins is important when performing segmental isolation of the pulmonary veins in patients with atrial fibrillation.

Response of pulmonary vein potentials to premature stimulation

Pulmonary Vein Potentials. Introduction: Pulmonary vein potentials reflect depolarization of muscle fascicles within the myocardial sleeves that surround the pulmonary veins. The response of pulmonary vein potentials to premature stimulation has not been described.

Pulmonary Vein Isolation: Comparison of Bipolar and Unipolar Electrograms at Successful and Unsuccessful Ostial Ablation Sites

Electrogram Analysis. Introduction: No prior studies have quantitatively analyzed the characteristics of bipolar or unipolar electrograms that may be helpful in identifying successful ostial ablation sites in patients with atrial fibrillation undergoing segmental pulmonary vein isolation.

Randomized Comparison of Bipolar versus Unipolar Plus Bipolar Recordings During Segmental Ostial Ablation of Pulmonary Veins

Unipolar vs Bipolar Electrograms. Introduction: Segmental ostial ablation to isolate pulmonary veins is guided by pulmonary vein potentials. The aim of this prospective randomized study was to compare the utility of unipolar plus bipolar electrograms versus only bipolar electrograms as a guide for segmental ablation to isolate the pulmonary veins in patients with atrial fibrillation.

Analysis of Age of Onset of Accessory Pathway- Mediated Tachycardia in Men and Women

diated tachycardia. 1‐4 However, a detailed analysis of the inter-relationships between gender, accessory pathway location, and the age of onset of accessory pathway-mediated tachycardia has been lacking. Therefore, the purpose of this study was to analyze the interactions between gender, accessory pathway location, and the age of onset of accessory pathwaymediated tachycardia. ••• The subjects of this study were 910 patients who underwent an electrophysiologic study at the University of Michigan Medical Center and met the following selection criteria: a history of symptomatic paroxysmal tachycardia; the ability to recollect the age of onset of the tachycardia; a single accessory pathway; an inducible accessory pathway-mediated tachycardia in the electrophysiology laboratory; and successful radiofrequency ablation of the accessory pathway. Patients who had 1 mechanism of tachycardia or 1 accessory pathway were excluded from the study. There were 536 men (59%) and 374 women (41%), and their mean age at the time of the electrophysiologic study was 37 15 years ( SD; range 10 to 84 years). The location of the accessory pathways was classified as being left sided, right sided, or septal, according to the site at which successful radiofrequency ablation was achieved. Among the 910 accessory pathways, 541 (59%) were left sided, 131 (14%) were right sided, and 238 (26%) were septal. In 328 patients (36%), the accessory pathway was concealed and capable only of retrograde conduction, and in the remaining 64% of patients, the accessory pathway was manifest and conducted in the anterograde direction. Continuous variables are expressed as mean 1 SD. Student’ s t test was used to compare 2 groups. Analysis of variance was used when comparisons involved 2 groups. When group differences were found, 1-way analysis of variance was followed by the

Incidence and clinical significance of inducible atrial tachycardia in patients with atrioventricular nodal reentrant tachycardia.

Significance of Atrial Tachycardia. Introduction: The purpose of this prospective study was to determine the prevalence and clinical significance of inducible atrial tachycardia in patients undergoing slow pathway ablation for AV nodal reentrant tachycardia who did not have clinically documented episodes of atrial tachycardia.

Comparison of amiodarone versus ibutilide for the prevention of immediate recurrences of atrial fibrillation during pulmonary vein isolation.

During segmental ostial ablation for pulmonary vein isolation, pulmonary vein potentials are easily identified during sinus rhythm or left atrial pacing. Therefore, maintenance of atrial fibrillation (AF) during the procedure is desirable. However, cardioversion is occasionally followed by an immediate recurrence of AF. This study compared the efficacy of ibutilide and amiodarone in preventing immediate recurrences of AF in patients who underwent pulmonary vein isolation. The subjects of this study were 25 patients (mean age 56 +/- 10 years) who underwent pulmonary vein isolation for AF who had an immediate recurrence of AF within 60 seconds after 2 transthoracic cardioversions. The patients were randomized to receive an infusion of either 300 mg of amiodarone over 10 minutes or 1 mg of ibutilide over 5 minutes. Cardioversion was repeated 15 minutes after the drug infusion. If immediate recurrences of AF occurred 2 more times, the alternative study drug was administered, and cardioversion was repeated. Immediate recurrences of AF were suppressed by amiodarone in 8 of 10 patients (80%), and by ibutilide in 9 of 15 patients (60%, p = 0.4). After crossover, immediate recurrence of AF was suppressed in 2 of 6 patients (33%) by amiodarone, and in 1 of 2 patients (50%) by ibutilide (p = 0.6). Ibutilide and amiodarone, when used alone or in combination, prevented immediate recurrences of AF in 20 of 25 patients (80%). There were no adverse drug effects. Ibutilide and amiodarone were equally effective in suppressing immediate recurrences of AF. Overall, immediate recurrences of AF can be prevented by amiodarone and/or ibutilide in 80% of patients.