Effect Of Pulmonary Vein Isolation Research Articles

Clinical effectiveness of pulmonary vein isolation for arrhythmic events in a patient with catecholaminergic polymorphic ventricular tachycardia

An 18-year-old woman with catecholaminergic polymorphic ventricular tachycardia (CPVT) underwent pulmonary vein isolation (PVI) because of frequent and inappropriate shocks from an implantable cardioverter defibrillator (ICD) associated with atrial fibrillation (AF) with a rapid ventricular response. While the PVI did not completely suppress the AF induced by an isoproterenol infusion, the Holter monitor recordings demonstrated a major decrease in the clinical episodes of AF and ventricular tachyarrhythmias in association with a reduced high-frequency (HF) component and ratio of the low-frequency (LF) component power to the HF component (LF/HF) after the PVI. The PVI can decrease the substrates that trigger and maintain the AF when it involves a pulmonary vein origin, and may exert an additional effect on the sympathetic nerve input to the heart. The PVI may be an adjunctive therapy for CPVT cases with drug refractory AF causing inappropriate ICD discharges.

Impact of pulmonary vein isolation on the autonomic modulation in patients with paroxysmal atrial fibrillation and prolonged sinus pauses

The efficacy of catheter-based pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) and prolonged sinus pauses [bradycardia-tachycardia syndrome (BTS)] has been already described. However, the effects of PVI on autonomic modulation in BTS patients remain to be determined. We, therefore, examined the alteration in the autonomic modulation through the PVI procedure by using a heart rate variability (HRV) analysis of 24 h ambulatory monitoring. This study consisted of 26 symptomatic paroxysmal AF patients either with prolonged sinus pauses on termination of AF (>3.0 s, BTS group, n = 11) or without any evidence of sinus node dysfunction (control group, matched for sex and age, n = 15) who underwent PVI. All 11 BTS patients became free from both AF and prolonged sinus pauses without pacemaker implantation (23 +/- 14 months of observation). The mean heart rate significantly increased in the control group (P < 0.05), but not in the BTS group after the PVI procedure, although the HRV parameters of root-mean-square successive differences in the adjacent NN intervals, standard deviation of the NN intervals, and high frequency did significantly decrease in both groups (P < 0.05). Although the parasympathetic modulation was significantly attenuated after the PVI procedure, the mean heart rate did not increase in the BTS patients, probably due to the pre-existing sinus node dysfunction.

Effect of pulmonary vein isolation on the distribution of complex fractionated electrograms in humans

Targeting of complex fractionated electrograms (CFEs) has been used as an adjunctive strategy to pulmonary vein isolation (PVI) in patients with persistent atrial fibrillation (AF). However, it is unclear whether CFEs should be targeted before or after PVI. The purpose of this study was to examine the effect of PVI on CFE distribution in humans. We compared left atrial (LA) CFE maps acquired using the NavX system before and after PVI in patients with persistent AF. CFE maps were constructed from bipolar electrograms acquired from a circular mapping catheter. At each point, the mean AF cycle length (CL) was calculated automatically by averaging the intervals between deflections over a 4-second window. Sites with mean CL < or =120 ms were considered CFE+. A total of 22 consecutive patients (82% male, age 58 +/- 9 years) were studied. At baseline, 47% of the LA was encompassed by electrograms with CL <120 ms. PVI had a significant effect on CFE characteristics, with an increase in mean LA AF CL (144 ms pre-PVI vs. 214 ms post-PVI; P <.01) and a decrease in CFE+ LA surface area (47% vs 23%; P <.01). There was significant reduction in CFE burden after PVI in both PV (50% vs. 6%; P <.01) and non-PV (61% vs. 39%; P <.01) regions. In patients with persistent AF, PVI results in a significant decrease in both PV and non-PV areas of CFE. To limit extensive LA ablation, PVI should be performed before targeting CFE when a combined approach is pursued.

Abstract 2752: Pulmonary Vein Isolation With And Without Additional Ablation Of Complex Fractionated Electrograms In Paroxysmal Atrial Fibrillation: Long-term Results Of A Prospective Randomized Study

Introduction: Segmental pulmonary vein isolation (PVI) leads to elimination of paroxysmal atrial fibrillation (AF) in approximately 75% of patients. Ablation of complex fractionated atrial electrograms (CFAE) is an alternative ablation strategy. In this prospective randomized study the long-term effect of PVI alone is compared to the effect of combined PVI and CFAE ablation in paroxysmal AF. Methods: 98 patients with paroxysmal AF (57±10 years, 74 male) were randomly assigned to PVI (48 patients) or PVI+CFAE ablation (50 patients). Additional CFAE ablation was performed in the PVI+CFAE group if AF was still inducible after PVI. Follow-up results were assessed with repetitive 7 days Holter ECG and clinical evaluation including repeat ablations. Results: Additional CFAE ablation was performed in 30/50 (60%) patients of the PVI+CFAE group with still inducible AF after PVI. In each group, 2 patients were lost to long term follow-up. In the intention-to-treat analysis at 3 months and after 19±8 months, there was no significant difference between both groups (36/48 [75%] and 34/46 [74%] patients in the PVI and 37/50 [73%] and 40/48 [83%] of patients in the PVI+CFAE ablation group in sinus rhythm [p=0.32]). In subgroup analysis, patients actually treated with the combined PVI+CFAE ablation approach had a significantly better long-term success (25/28; 89%) than patients with still inducible AF who underwent PVI only (22/30;73%; p=0.02). In both groups repeat ablations were performed in 31% (PVI group; 15/48 patients) and 35% (PVI+CFAE group; 17/48 patients) (p=n.s). After 9 months, significantly more patients in the PVI+CFAE group experienced sustained regular atrial tachycardia than in the PVI group (6/44 versus 1/39 patients, P=0.02). Conclusion: The combination of PVI and CFAE ablation was equally effective than PVI alone in reaching freedom of AF in the intention-to-treat analysis. During long-term follow-up, patients actually treated with combined PVI+CFAE ablation had a significantly better outcome (89% vs. 73%). However, the rate of ablation-induced regular atrial tachycardias is inreased.

Biatrial anatomical reverse remodelling after radiofrequency catheter ablation for atrial fibrillation: evidence from real-time three-dimensional echocardiography

Reports using two-dimensional echocardiography have indicated that radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) results in a reduction in the left atrial (LA) size. Furthermore, the effect of pulmonary vein isolation (PVI) on right atrial (RA) anatomical remodelling has not been studied. Three-dimensional echocardiography (3DE) allows us to more precisely quantify atrial volume. Our aim was to assess the effect of PVI on biatrial anatomical remodelling using real-time 3DE. We prospectively studied 91 patients (age 59 +/- 8 years, 79 males) referred for RFCA of paroxysmal (n = 79) or chronic (n = 19) AF. Left atrial and RA volumes were measured using real-time 3DE at baseline and after 6 months of follow-up. Data on AF recurrences were also collected. Left atrial volume was significantly reduced at follow-up when compared with baseline (51 +/- 16 vs. 60 +/- 21 mL, P < 0.001). The same occurred with RA volume (43 +/- 17 vs. 50 +/- 20 mL, P = 0.001). The reduction in the LA volume was more marked in patients with chronic than in those with paroxysmal AF (17 +/- 16 vs. 6 +/- 17 mL, P = 0.017). Patients with AF recurrence (23%) showed similar atrial volume reduction compared with those who were seemingly cured. Three-dimensional echocardiography shows evidence of biatrial anatomical reverse remodelling after RFCA for AF. A reduction in the atrial volume occurs despite recurrence of AF.

Combined Effect of Pulmonary Vein Isolation and Ablation of Cardiac Autonomic Nerves for Atrial Fibrillation

This study was designed to determine whether endocardial high-frequency stimulation at the pulmonary vein (PV) antrums can localize cardiac autonomic ganglionated plexi (GP) and whether ablation at these sites can evoke a vagal response and provide a long-term benefit after PV isolation (PVI) for atrial fibrillation (AF). Radiofrequency ablation of each PV antrum was performed in 21 patients with paroxysmal AF (n = 17) or persistent (n = 4) AF. In 8 patients with paroxysmal AF, a ring electrode catheter was placed at each PV antrum. High-frequency stimulation prolonged the R-R interval in 6 of 8 patients at the left superior (LS) PV, in 3 of 8 patients at the left inferior (LI) PV, in 3 of 8 patients at the right superior (RS) PV, and in 3 of 8 patients at the right inferior (RI) PV. A decrease in sinus rate > 20% was observed in 4 of 21 patients during LS PVI, in 2 of 21 patients during RS PVI, and in 1 of 2 patients during RI PVI. Atrioventricular block or a > 5 second pause was observed in 5 of 21 patients during LS PVI. AF recurred during the follow-up period in 5 of the 16 patients (31%) who had no atrioventricular block or > 5 second pause during PVI but did not recur in 5 patients in whom atrioventricular block or a > 5 second pause developed during PVI. GP can be identified by endocardial stimulation. The AF recurrence rate is decreased when a vagal response is achieved by radiofrequency ablation.

Atrial Fibrillation After Cardiac Transplantation: Experience in 498 Consecutive Cases

Some contemporary surgical treatments for atrial fibrillation involve creating only a subset of the lesions made in the classic Cox Maze procedure. This subset often consists of pulmonary vein isolation and partial cardiac denervation. Orthotopic heart transplantation, by necessity, results in pulmonary vein isolation, albeit with total cardiac denervation. Although postoperative atrial fibrillation (POAF) and atrial fibrillation may differ in cause, they have similar underlying mechanisms and often respond to the same treatments. Therefore, we reviewed the incidence of POAF in heart transplant recipients to assess the antiarrhythmic effects of pulmonary vein isolation and cardiac denervation. We reviewed the charts of 498 consecutive patients who underwent orthotopic heart transplantation at a single institution during a 15-year period. Twenty-seven patients (5.4%) experienced POAF within 60 days of transplant. In 9 of these patients, POAF occurred within 2 weeks of a biopsy-proven transient rejection episode; excluding these patients from the analysis revealed a non-rejection-associated POAF rate of 18 of 489 patients (3.7%). Despite the long ischemic times, extensive manipulation of the transplanted heart, and the postoperative administration of proarrhythmic inotropic agents that cardiac transplantation typically involves, this procedure is associated with a low incidence of POAF, particularly if patients in whom rejection and POAF were temporally related are excluded. These findings suggest that complete cardiac denervation and pulmonary vein isolation protect heart transplant recipients from POAF, thus supporting the notion that similar lesions may be useful in the treatment of other types of atrial fibrillation.

The Effects of Pulmonary Vein Isolation on the Morphology of P Waves: The Contribution of Pulmonary Vein Muscle Excitation to the Formation of P Waves

Although the pulmonary veins have been demonstrated to play an important role in initiating and perpetuating atrial fibrillation, the role that cardiac muscle tissue in the pulmonary veins plays regarding the formation of P wave remains to be elucidated. We sought to clarify the contribution of pulmonary vein cardiac muscles to the formation of P waves by analyzing the P loops/waves in patients with atrial fibrillation. The subjects in this study consisted of 21 patients (mean age, 57 +/- 10 years) with drug-refractory, paroxysmal atrial fibrillation who had undergone a segmental ostial isolation of all four pulmonary veins from the left atrium. Vectorcardiograms, intracardiac electrograms, and electrocardiograms (ECGs) were recorded before and after pulmonary vein isolation. The morphology of P waves changed after pulmonary vein isolation procedures with a significant increase in the maximal amplitude of both the leftward force in lead x and the anterior force in lead z (P < 0.05). The middle part (second one of three parts) of P loop on the horizontal plane shifted anteriorly and leftward after pulmonary vein isolation. Intracardiac electrograms in the pulmonary veins demonstrated the averaged activation times of all four pulmonary veins to range from 40% to 84% of the P duration. The excitation of cardiac muscle tissue, which has migrated to the pulmonary veins, was thus found to play an important role in the formation of the middle part of the P wave/loop.

The Effects of Pulmonary Vein Isolation on the Dominant Frequency and Organization of Coronary Sinus Electrical Activity During Permanent Atrial Fibrillation

Pulmonary vein isolation (PVI) has been shown to suppress atrial fibrillation (AF). We examined the effects of PVI on disorganization and dominant frequencies (DF) in patients with permanent AF. Twenty-eight patients with permanent AF (>6 months) who failed > or =1 antiarrhythmic drugs (AAD) and > or =2 cardioversions (CV) with AF reversion <30 minutes after CV were included. PVI and isolation of DFs in pulmonary veins (PVs) was performed during AF. Fast Fourier transformations of atrial electrograms were performed. Disorganization index (DI) was defined as the percentage of time spent in type III AF during 1-minute continuous recordings. The temporal stability and reproducibility of DIs from the same sites were verified over time prior to ablation. Highly disorganized AF activity concentrated in the posterior left atrium (PLA) including sites at the left atrial (PV-LA) junction (55.7% of sites in PLA, 32.9% in septum, and 11.4% in other sites). DF and DI from the coronary sinus (CS) before and after PVI were analyzed. PVI reduced the DI (14.3 +/- 25.0% before PVI vs 4.6 +/- 8.6% after PVI; P < 0.02). There was significant reduction of DI in 26 of 28 patients. The DF remained unchanged (5.6 +/- 1.3 Hz before PVI vs 5.9 +/- 0.9 Hz after PVI; P = 0.31). After a follow-up of 30 +/- 11 months, 15 (54%) of patients are free of symptomatic AF, 3 (10%) in sinus rhythm on AAD, 5 (18%) with paroxysmal AF, 4 (14%) in chronic AF, and 1 (4%) with atypical flutter. In the vast majority of patients with chronic AF, PVI reduces AF disorganization without affecting the DF as measured in the CS.

Reversal of Left Ventricular Dysfunction Following Ablation of Atrial Fibrillation

Evaluation of ventricular rate control in atrial fibrillation (AF) can be difficult, and the presence of an AF-induced ventricular cardiomyopathy due to intermittent poor rate control or other causes may be underestimated. The outcome with AF ablation in patients with a decreased left ventricular ejection fraction (LVEF) may provide insight into this important clinical issue. To determine the effect of pulmonary vein isolation on LVEF in patients with AF and decreased LVEF (< or = 50%). Ablation consisted of proximal isolation of arrhythmogenic pulmonary veins (PVs) and elimination of non-PV triggers. LVEF was determined within 24 hours after ablation and again at up to 6 months follow-up. Transtelephonic monitoring was performed routinely for 2-3 weeks prior to ablation, at 6 weeks, and 6 months post and with symptoms following ablation. AF control was defined as freedom from AF or marked (>90%) reduction in AF burden on or off previously ineffective antiarrhythmic medication. AF ablation was performed in 366 patients and 67 (18%) patients had decreased LV function with a mean LVEF of 42 +/- 9%. An average of 3.4 +/- 0.9 PVs were isolated. AF control in the depressed LVEF group compared favorably with the normal EF group (86% vs. 87% P = NS), although more redo procedures were required (1.6 +/- 0.8 vs 1.3 +/- 0.6 procedures; P < or = 0.05). Only 15 of 67 patients (22%) with decreased LVEF had shown tachycardia (>100 bpm) on repeated preablation ECG recordings during AF. In the decreased LVEF group, the LVEF increased from 42 +/- 9% to 56 +/- 8% (P < 0.001) after ablation. Patients with AF and decreased LVEF undergoing AF ablation have similar success to patients with normal LVEF and have improvement in LVEF after ablation. These results suggest the presence of a reversible AF-induced ventricular cardiomyopathy in many patients with AF and depressed LV function. The presence of under-recognized and reversible cardiomyopathy even when tachycardia is not persistent is important to recognize.

Effect of pulmonary vein isolation on the left-to-right atrial dominant frequency gradient in human atrial fibrillation

We previously demonstrated the existence of a left-to-right atrial dominant frequency gradient during paroxysmal but not persistent atrial fibrillation (AF) in humans. One possible mechanism of the left-to-right dominant frequency gradient involves the role of the pulmonary veins (PVs) in AF maintenance. The purpose of this study was to examine the effect of PV isolation on the dominant frequency gradient and outcome after PV isolation. Patients with either paroxysmal or persistent AF were studied. Recordings were made from catheters in the coronary sinus (CS), posterior right atrium (RA), and posterior left atrium (LA) during AF before and after PV isolation. Mean left-to-right dominant frequency gradient was measured before and after segmental PV isolation. Patients were followed for AF recurrence after PV isolation. Twenty-seven patients with paroxysmal (n = 15) or persistent (n = 12) AF were studied. In the paroxysmal group, baseline dominant frequency was greatest in the posterior LA with a significant left-to-right atrial dominant frequency gradient (posterior LA = 6.2 +/- 0.9 Hz, CS = 5.8 +/- 0.8 Hz, posterior RA = 5.4 +/- 0.9 Hz; P <.001). After PV isolation, there was no regional difference in dominant frequency (5.9 +/- 0.7 Hz vs 5.7 +/- 0.6 Hz vs 5.7 +/- 0.7 Hz, respectively; P = NS). In the persistent AF group, there was no overall difference in dominant frequency among sites before or after PV isolation (P = NS); however, patients with long-term freedom from AF after PV isolation had a higher left-to-right dominant frequency gradient compared with patients with recurrent AF (0.4 vs 0.1 Hz; P <.05). PV isolation results in a loss in the left-to-right dominant frequency gradient in patients with paroxysmal AF. This finding supports the critical role of PVs in the maintenance of ongoing paroxysmal AF. Patients with persistent AF and a baseline left-to-right dominant frequency gradient have a better success rate with PV isolation alone compared with patients without a dominant frequency gradient.

Effect of pulmonary vein isolation on atrial arrhythmogenic substrates in atrial fibrillation

Background: It has been reported that pulmonary veins (PVs) have a major role in initiation or maintainance of atrial fibrillation (AF) and PV isolation is effective therapy to modify atrial arrhythmogenic substrates for AF elimination. However, its mechanism remains unclear.

Quantification of atrial tachyarrhythmia burden with an implantable pacemaker before and after pulmonary vein isolation.

Long-term efficacy of pulmonary vein (PV) ostial isolation for paroxysmal atrial fibrillation is difficult to assess. We evaluated the net duration of atrial tachyarrhythmia episodes (burden), atrial tachyarrhythmia episode frequency, and quality-of-life (QOL) before and after PV isolation in patients with an existing pacemaker featuring extensive diagnostic capabilities. Due to frequent recurrences of paroxysmal atrial fibrillation, PV isolation was performed 21 +/- 10 months following pacemaker implantation on 12 patients (57 +/- 5 years) with normal left ventricular function. Atrial tachyarrhythmia burden (ATB) and episode frequency were monitored daily by the device both pre- and postablation. QOL questionnaires were collected at ablation and 1, 3, and 6 months thereafter. Patients were followed for 20 +/- 9 and 11 +/- 9 months pre- and postablation, respectively. Membrane-active antiarrhythmic medications were discontinued after ablation in 8 of 12 patients. PV isolation resulted in a significant reduction of ATB from a median of 3.2 hours/day (preablation) to 0.2 hours/day (postablation, P < 0.01, Wilcoxon signed-rank test). The median tachyarrhythmia frequency was 6.4 episodes/day (preablation) and 0.3 episodes/day (postablation, P = 0.09). QOL measures significantly improved over the data collection intervals (P < 0.05). Tachyarrhythmia burden was positively associated with Symptom Checklist frequency and severity (P < 0.01). Significant long-term reductions in total ATB (symptomatic and asymptomatic) were observed. Furthermore, reductions in ATB were associated with improvements in QOL measures. Extensive monitoring capabilities in implantable devices help provide complete disclosure on the effect of PV isolation in paroxysmal atrial fibrillation patients.

Pulmonary vein isolation for atrial fibrillation in patients with symptomatic sinus bradycardia or pauses.

Sick sinus syndrome is commonly associated with tachyarrhythmias and bradyarrhythmias that often are symptomatic. The aim of this study was to assess the effect of pulmonary vein isolation in patients with sick sinus syndrome and atrial fibrillation (AF). Three hundred fourteen consecutive patients who underwent pulmonary vein isolation between December 2000 and January 2002 were included in the study. Thirty-one patients had sick sinus syndrome, which was defined as a preprocedural history of symptomatic sinus bradycardia or pauses. Endpoints included AF recurrence, change in the frequency of sinus pauses, and symptoms of presyncope or syncope, as well as mean heart rate and percentage of atrial pacing in patients with pacemakers implanted prior to the pulmonary vein isolation. Patients had AF for an average of 6 +/- 3 years. Patients were 58 +/-8 years old and had ejection fractions of 55 +/- 4%. Sixty-one percent had implanted pacemakers. AF recurred within 6 months in 4 patients. Two had a successful second pulmonary vein isolation procedure. There were no recurrences of presyncopal events (P < 0.05) or documented sinus pauses (P < 0.05) after successful pulmonary vein isolation in the patients without permanent pacemakers. Patients with pacemakers had a 13-fold reduction in the percentage of atrial pacing (P < 0.05). Both groups showed a significant increase in average heart rates at 6-month follow-up. Cure of AF by pulmonary vein isolation helped resolve the clinical manifestations of sick sinus syndrome, suggesting that the occurrence of AF and/or the associated treatment could be partially responsible for sick sinus syndrome.

Effect of Pulmonary Vein Isolation on Quality of Life in Patients with Paroxysmal Atrial Fibrillation

Background: Recent studies have demonstrated that delivering radiofrequency energy to isolate the pulmonary veins (PVs) can cure patients with paroxysmal atrial fibrillation (PAF). Objective: To quantify the effects of radiofrequency catheter isolation of PVs on quality of life (QoL), symptom burden and non-scheduled visiting to physicians in patients with PAF. Methods: Thirty consecutive patients referred for radiofrequency ablation of PAF were included. Questionnaires were administered retrospectively, 6.3 months after the ablation procedure. QoL was measured by the SF-36 (a measure of general health status) and symptoms and health care utilization by a locally constructed questionnaire. Results: Before ablation, patients with PAF had significantly lower scores on all SF-36 subscales with the exception of the pain subscale, compared with a healthy control group. Apart from bodily pain all subscales significantly improved after PV isolation. Twenty patients had an improvement in their total health perception. PV isolation significantly reduced the frequency of episodes of atrial fibrillation (AF) and the proportion of nonscheduled contacts to physicians for AF. Conclusion: QoL in patients with PAF is significantly impaired. PV isolation improves the QoL and reduces the frequency and severity of symptoms and non-scheduled contacts to physicians.

Effect of pulmonary vein isolation on atrial fibrillation cycle length

Effect of pulmonary vein isolation on atrial fibrillation cycle length

Effects of Pulmonary Vein Isolation Using Intraoperative Radiofrequency Catheter Ablation for the Treatment of Atrial Fibrillation Associated with Mitral Valvular Heart Diseases

Background and Objectives:The pulmonary veins and surrounding ostial areas frequently house focal triggers or reentrant circuits critical to the genesis of atrial fibrillation (AF). The purpose of this study was to assess the efficacy of pulmonary vein isolation, aided by intraoperative radiofrequency catheter ablation, for the treatment of AF associated with mitral valvular heart disease. Subjects and Methods:32 consecutive patients with AF associated with mitral valvular disease, requiring mitral valvular replacement or valvuloplasty were included. We divided these patients into two groups. The first group, PVI, consisted of 16 patients that had mitral valvular operations with intraoperative radiofrequency pulmonary vein isolation, and the other 16 patients, the controls, had mitral valvular operation only. The conversion rate to sinus rhythm and other clinical data were compared between the two groups. Results:Circumferential pulmonary vein isolation, with radiofrequency catheter ablation, was achieved in an average of 15±3 min. There were no mortalities or morbidities associated with this procedure. In the immediate postoperative period, the conversion rate to normal sinus rhythm in the PVI group was significantly higher than in the controls (81% vs. 37.5% p=0.016). After 21±4 weeks of follow up, the sinus rhythm maintenance rates in PVI group was also significantly higher than those of the control group (75% vs. 31.2% p=0.01). Conclusion:Circumferential pulmonary vein isolation, aided by intraoperative radiofrequency catheter ablation, is simple and effective for the treatment of chronic atrial fibrillation associated with mitral valvular disease. (Korean Circulation J 2002;32(7):596-603)