Pulmonary Vein Potentials Research Articles

Repeat procedures using the second-generation cryoballoon for recurrence of atrial fibrillation after initial ablation with conventional radiofrequency.

Pulmonary vein isolation is now widely accepted for the treatment of symptomatic atrial fibrillation refractory to antiarrhythmic drugs. However, multiple procedures are often required to significantly reduce atrial fibrillation (AF) recurrence. In the present study, we analyzed the acute results and the midterm clinical outcome of a second-generation cryoballoon ablation (CB-A) performed during repeat procedures for recurrence of AF after an initial procedure performed with conventional radiofrequency (RF). Consecutive patients with paroxysmal and persistent AF who underwent pulmonary vein isolation by CB-A from June 2012 in our hospital as a redo procedure after a previous pulmonary vein isolation with RF were retrospectively included in this analysis. Forty-seven patients having undergone CB-A as a redo procedure were considered for our analysis. Pulmonary vein potentials were documented in 83 pulmonary veins (PV) that were all successfully re-isolated using the CB-A. Transient phrenic nerve palsy was the only complication occurring in our study cohort. After a mean follow-up of 15±8months, 76.6% of patients were free from recurrence of atrial fibrillation. If taking into consideration a 3-month blanking period, 83% of patients were free from recurrence. The success rate in patients affected by paroxysmal AF was 87% at final follow-up following the blanking period. The second-generation CB is effective in treating recurrence of AF after a previous ablation performed with conventional RF. Considering a 3-month blanking period, 83% of the patients were free from any atrial tachycardia recurrence during a 15-month follow-up. This approach proved particularly successful in patients affected by paroxysmal AF.

Adenosine administration during hybrid atrial fibrillation ablation to test dormant pulmonary vein conduction

BackgroundAdenosine administration after initial pulmonary vein isolation (PVI) reveals dormant conduction and predicts atrial fibrillation (AF) recurrence. Elimination of dormant conduction when present may increase a long-term success rate of AF ablation procedures. There are no studies till date using adenosine to reveal acute reconduction of pulmonary veins (PVs) after epicardial PVI during a hybrid AF ablation procedure.MethodsWe included 24 patients (21 male, 55 ± 9 years) undergoing hybrid ablation for symptomatic paroxysmal (n = 12) and persistent (n = 12) AF, using an epicardial bipolar radiofrequency clamp to perform PVI. All antiarrhythmic medications were discontinued 5 days prior to the procedure, except for patients on amiodarone. Thirty minutes after PVI and once sinus rhythm was obtained, a bolus of adenosine (12 to 36 mg) was administered intravenously. The subsequent response was assessed for each PV (n = 96) using an in situ circular mapping catheter.ResultsDormant conduction (i.e., the reappearance of PV potentials during at least one beat) was seen in 1 out of 96 PVs (1%). If reconduction was seen, further endocardial ablation using a 3.5-mm irrigated tip catheter was performed until no more reconduction occurred after repeating the adenosine bolus.ConclusionsAdenosine administration after PVI with the use of an epicardial bipolar radiofrequency clamp in the setting of hybrid AF ablation reveals acute reconduction in 1% of the PVs.

Second generation cryoballoon ablation for atrial fibrillation in young adults: midterm outcome in patients under 40 years of age.

Pulmonary vein isolation (PVI) has been demonstrated more effective in young patients, in which the substrate for atrial fibrillation (AF) is probably more confined to pulmonary vein potentials. The present study sought to focus on the midterm outcomes in patients under 40 years having undergone PVI with the Cryoballoon Advance because of drug resistant AF. Between June 2012 and December 2015, 57 patients having undergone Cryoballoon ablation (CB-A) below 40 years of age for AF in our centre were retrospectively analysed and considered for our analysis. All patients underwent this procedure with the 28 mm Cryoballon Advance. All 227 veins were successfully isolated without the need for additional focal tip ablation. Median follow-up was 18 ±10 months. The freedom from AF after a blanking period of 3 months was 88% in our cohort of patients younger than 40 years old. The most frequent periprocedural complication was related to the groin puncture and occurred in 2 patients. After a single procedure, the only univariate predictor of clinical recurrence was the diagnosis of hypertrophic cardiomyopathy. Young patients affected by AF can be effectively and safely treated with CB-A that grants freedom from AF in 88% of the patients at 18 months follow-up following a 3-month blanking period. All veins could be isolated with the large 28 mm Cryoballoon Advance only.

A Thin Left Atrial Antral Wall Around the Pulmonary Vein Reflects Structural Remodeling by Atrial Fibrillation and is Associated with Stroke.

PurposeCircumferential pulmonary (PV) vein isolation (CPVI) is the most important treatment strategy for atrial fibrillation (AF). While understanding left atrial wall thickness around PVs (PVWT) prior to catheter ablation is important, its clinical implications are not known. This study aimed to evaluate PVWT characteristics according to underlying disease and to identify associations between PVWT and reconnections of PV potentials (PVPs) in redo ablation.Materials and MethodsIn 28 patients who underwent redo-AF ablation, PVWT and reconnected PVPs were evaluated at 12 sites (1–12 o'clock) around each PV. Clinical characteristics including stroke and CHA2DS2-VASc scores were analyzed according to the PVWT.ResultsThe PVWT was thicker in males than females (p<0.001) and in those with diabetes (p=0.045) or heart failure (p=0.002) than in those without. Patients with strokes or high CHA2DS2-VASc scores (≥3) had significantly thinner PVWTs than those without strokes or low CHA2DS2-VASc scores (p<0.001). In redo-ablation, reconnected PVPs were detected in 60 (53.6%) of 112 PVs, and the PVs were thicker (p<0.001) and had more reconnected PVs (p=0.009) than right PVs. A PVWT of >0.6 mm predicted PV reconnections with a sensitivity of 76.7% and specificity of 52.2% with an area under the curve of 0.695.ConclusionThick PVWs were associated with diabetes and heart failure, and also showed significant inverse correlations with stroke and the CHA2DS2-VASc score. Thick PVWs were associated with reconnected PVPs after the CPVI, which were related to AF recurrence.

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

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

The utility of atrial pacing for identifying the electrical breakthrough sites between the left atrium and pulmonary veins

BackgroundCircumferential pulmonary vein (PV) isolation for atrial fibrillation (AF) is occasionally difficult to achieve because electrical breakthrough sites (EBSs) between the left atrium (LA) and PVs cannot be identified during ablation especially in the carina regions. MethodsThe left PVs (Lt.PVs) of 60 AF patients and the right PVs (Rt.PVs) of 37 patients undergoing PV isolation were studied. When PV isolation was not achieved after the initial circumferential PV isolation, atrial pacing was repeatedly performed from the distal coronary sinus (CSd) and high right atrium (HRA), and the time interval from the stimulus to the earliest PV potential (stimulus-PV interval) was measured using circular mapping catheters at each PV until PV isolation was achieved. When PV isolation was achieved via local Radiofrequency (RF) deliveries, those regions were diagnosed as final EBSs. We classified the final EBSs into six segments for each PV (anterior and posterior PV walls of the roof, carina, and bottom) and investigated the relationship between the final EBSs and stimulus-PV intervals. ResultsFor Lt.PVs, the stimulus-PV intervals during CSd pacing were significantly shorter than during HRA pacing at the Lt.PV anterior carina and bottom (90±28ms vs. 125±26ms, P<0.001 and 84±20ms vs. 148±24ms, P=0.028, respectively), but there was no significant difference in the Lt.PV roof and any posterior segments. For Rt.PVs, the stimulus-PV interval from both pacing sites exhibited no significant difference between either segment. ConclusionsThis pacing method may help to identify whether EBSs are located in the anterior Lt.PVs. Improved recognition of EBSs through pacing from different sites would be helpful for achieving PV isolation.

Adenosine testing during cryoballoon ablation and radiofrequency ablation of atrial fibrillation: A propensity score–matched analysis

The infusion of adenosine triphosphate after radiofrequency (RF) pulmonary vein (PV) isolation (PVI), which may result in acute transient PV-atrium reconnection, can unmask dormant conduction. The purpose of this study was to compare the incidence and characteristics of dormant conduction after cryoballoon (CB) and RF ablation of atrial fibrillation (AF). Of 414 consecutive patients undergoing initial catheter ablation of paroxysmal AF, 246 (59%) propensity score-matched patients (123 CB-PVI and 123 RF-PVI) were included. Dormant conduction was less frequently observed in patients who underwent CB-PVI than in those who underwent RF-PVI (4.5% vs 12.8% of all PVs; P < .0001). The incidence of dormant conduction in each PV was lower in patients who underwent CB-PVI than in those who underwent RF-PVI in the left superior PV (P < .0001) and right superior PV (P = .001). The site of dormant conduction was mainly located around the bottom of both inferior PVs after CB-PVI. Multivariable analysis revealed that a longer time to the elimination of the PV potential (odds ratio 1.018; 95% confidence interval 1.001-1.036; P = .04) and the necessity of touch-up ablation (odds ratio 3.242; 95% confidence interval 2.761-7.111; P < .0001) were independently associated with the presence of dormant conduction after CB-PVI. After the elimination of dormant conduction by additional ablation, the AF-free rate was similar in patients with and without dormant conduction after both CB-PVI and RF-PVI (P = .28 and P = .73, respectively). The results of the propensity score-matched analysis showed that dormant PV conduction was less frequent after CB ablation than after RF ablation and was not associated with ablation outcomes.

Clinical recurrence and electrical pulmonary vein reconnections after second-generation cryoballoon ablation

Electrical reconnections after pulmonary vein isolation (PVI) are less common after second-generation cryoballoon than radiofrequency ablation. The purpose of this study was to investigate the incidence and characteristics of pulmonary vein (PV) reconnections after second-generation cryoballoon ablation in patients with and those without clinical recurrences. Forty patients with paroxysmal atrial fibrillation undergoing second procedures after cryoballoon ablation were enrolled. Twenty-five patients experienced clinical recurrences, and the remaining 15 did not. All 158 PVs were reevaluated a median [25th, 75th percentiles] of 6.0 [4.0-9.0] months after the initial procedure. In total, reconnections were detected in 39 PVs (24.7%) among 25 patients (62.5%). Reconnected PVs included 6 left superior (LS) (15.8%), 7 left inferior (LI) (18.4%), 5 right superior (RS) (12.5%), 20 right inferior (RI) (50.0%), and 1 left common (LC) (50.0%) PV. Reconnected PV potential conduction delays were a median of 112 [76-130], 103 [82-133], 84 [66-96], 68 [49-73], and 204 ms in the LS, LI, RS, RI, and LC PV, respectively. There was no significant difference between those with and those without clinical recurrences with regard to clinical characteristics, procedural results, incidence of reconnections (25/98 vs 14/60, P = .758), and PV conduction delays in each PV. The most common gap location was the RI PV bottom in both groups. Among 5 patients with reconnections of arrhythmogenic PVs (with atrial fibrillation initiation), 2 experienced clinical recurrences, whereas 3 did not. Non-PV foci (with atrial fibrillation initiation) were identified in a second procedures in 10 of 25 patients with clinical recurrences. The incidence and characteristics of PV reconnections after second-generation cryoballoon ablation were similar between patients with and those without clinical recurrences. The results should be considered when discussing the optimal dose of cryoballoon applications.

Incidence of real-time recordings of pulmonary vein potentials using the third-generation short-tip cryoballoon.

The third-generation Cryoballoon Advance Short-tip (CB-ST) has been designed with a 40% shortened tip length compared with the former second-generation CB Advance device. Ideally, a shorter tip should permit an improved visualization of real-time (RT) recordings in the pulmonary vein (PV) due to a more proximal positioning of the inner lumen mapping catheter. In the present study, we sought to analyse the rate of visualization of RT recordings in our first series of patients with the CB-ST device. All consecutive patients having undergone CB ablation using CB-ST technology were analysed. Exclusion criteria were the presence of an intracavitary thrombus, uncontrolled heart failure, moderate or severe valvular disease, and contraindications to general anaesthesia. A total of 60 consecutive patients (60.5 ± 11.2 years, 62% males) were evaluated. Real-time recordings were detected in 209 of 240 PVs (87.1%). Specifically, RT recordings could be visualized in 55 left superior PVs (91.7%), 51 left inferior PVs (85.0%), 53 right superior PVs (88.3%), and 50 right inferior PVs (83.3). The rate of visualization of RT recordings is significantly high during third-generation CB-ST ablation. Real-time recordings can be visualized in ∼87.1% of veins with this novel cryoballoon.

Data from renewable energy assessments for resort islands in the South China Sea.

Renewable energy assessments for resort islands in the South China Sea were conducted that involves the collection and analysis of meteorological and topographic data. The meteorological data was used to assess the PV, wind and hydropower system potentials on the islands. Furthermore, the reconnaissance study for hydro-potentials were conducted through topographic maps in order to determine the potential sites suitable for development of run-of-river hydropower generation. The stream data was collected for 14 islands in the South China Sea with a total of 51 investigated sites. The data from this study are related to the research article “Optimal combination of solar, wind, micro-hydro and diesel systems based on actual seasonal load profiles for a resort island in the South China Sea” published in Energy (Khan et al., 2015) [1].

Abstract 17461: Clinical Significance of No Pulmonary Vein Potential at Redo-procedure After Catheter Ablation for Atrial Fibrillation

Introduction: Long-lasting pulmonary vein isolation (PVI) has been shown to be the key determinants for clinical outcome in both patients with paroxysmal and persistent atrial fibrillation (AF). Hypothesis: Although reconnected PV potential (PVP) has been regarded as a main mechanism of AF recurrence after catheter ablation, PVIs are well preserved in some patients at redo-procedure after recurrence. Therefore, we explored the characteristics and clinical outcome of the patients with negative PVP at redo-procedure. Methods: Among 1522 patients with AF who underwent catheter ablation, 143 patients (79.0% male, 56.1±10.0 years old, 65.0% paroxysmal AF) refractory to antiarrhythmic drug underwent redo-procedure. PVP was not shown in 52 patients (PVP- group, 36.4%), but remaining 91 patients showed PVP (PVP+ group, 234/364 (64.3%) of PVs). We mapped triggers with isoproterenol infusion in both groups (after PVI in PVP+ group). Depending on mapping finding, we ablated non-PV foci and added linear ablation or complex fractionated atrial electrogram (CFAE)-guided ablation. Results: 1. PVP- group was independently associated with female gender (OR 2.64 95%CI 1.13~6.21, p=0.026) and later de novo clinical recurrence timing (OR 1.02 95% CI 1.00~1.04, p=0.047). 2. Additional linear ablations were more likely to be performed in PVP- group (92.2% vs. 61.5%, p&lt;0.001), but total ablation time (2411.3±1082.8 vs. 3144.8 ± 1412.5 sec, p=0.003) and procedure time (164.2± 51.4 vs. 144.2±47.1 min, p=0.027) were shorter in PVP- group than in PVP+ group. 3. During 18.4±10.2 months follow-up after redo-ablation, PVP- group showed significantly higher clinical recurrence rate than PVP+ group regardless of redo-ablation strategies (Kaplan Meier, Log Rank p=0.011). The presence of recurred PV connection (PVP+) was independently associated with lower recurrence of AF after repeat ablation (HR 0.46, 95% CI 0.21 - 0.98, p=0.043). Conclusions: AF patients with well-preserved PVI recurred later timing after de novo ablation, but showed poor clinical outcome after redo-ablation procedure, suggesting a potential AF progression.

Direct Pulmonary Vein Ablation With Stenosis Prevention Therapy.

The dominant location of electrical triggers for initiating atrial fibrillation (AF) originates from the muscle sleeves inside pulmonary veins (PVs). Currently, radiofrequency ablation (RFA) is performed outside of the PVs to isolate, rather than directly ablate these tissues, due to the risk of intraluminal PV stenosis. In 4 chronic canine experiments, we performed direct PV muscle sleeve RFA ± postablation drug-coated balloon (DCB) treatment with paclitaxel/everolimus. Of the 4 PVs, 2 PVs were ablated and treated with DCB, 1 PV was ablated without DCB treatment (positive control), and 1 PV was left as a negative control. Local electrograms were assessed in PVs for near-field signals and were targeted for ablation. After 12-14 weeks survival, PVs were interrogated for absence of near-field PV potentials, and each PV was assessed for stenosis. All canines survived the study period without cardiorespiratory complications, and remained ambulatory. In all canines, PVs that were ablated and treated with DCB remained without any significant intraluminal stenosis. In contrast, PVs that were ablated and not treated with DCB showed near or complete intraluminal stenosis. At terminal study, PV potentials remained undetectable. A blinded, histologic analysis demonstrated that ablated PVs without DCB treatment had extensive thrombus, fibrin, mineralization, and elastin disruption. Our chronic canine data suggest that direct PV tissue ablation without subsequent stenosis is feasible with the use of postablation DCBs.

Electrophysiologic Results After Thoracoscopic Ablation for Chronic Atrial Fibrillation

Thoracoscopic ablation for lone atrial fibrillation (AF) has evolved rapidly in the past decade. We investigated the electrophysiologic results and midterm durability of totally thoracoscopic ablation in patients with lone persistent AF. Seventy-nine consecutive patients with paroxysmal AF (8 patients, 10.1%), persistent AF (17 patients, 21.5%), and long-standing persistent AF (54 patients, 68.3%) were prospectively enrolled. Thoracoscopic ablation consisted of a bilateral closed-chest approach to performing pulmonary isolation (a box lesion), ganglionated plexus ablation, division of the Marshall ligament, and left atrial auricle resection. An electrophysiologic study was performed 5 days after the surgical procedure in 61 patients (77%). Freedom from AF was assessed with electrocardiograms or Holter monitoring every 3 months, with a mean follow-up of 12.1 (maximum, 28) months. No deaths or conversion to cardiopulmonary bypass occurred. During electrophysiologic study, 28 residual pulmonary vein potentials were observed in 15 patients (19%). Out of a total of 28 gaps, 20 (71%) were located in the superior and inferior ridges of pulmonary veins. Six gaps (21%) were detected in the carina of pulmonary veins. The mitral isthmus was ablated in 2 patients (7%). Freedom from AF at 2 years was 92.6 ± 3.3%. Freedom from cardiac-related events at 2 years was 74.7 ± 6.0%. Cox regression analysis demonstrated that the predictors of atrial arrhythmias were old age, hypertension, and left atrial volume index. Thoracoscopic ablation followed by electrophysiologic confirmation was safe and provided excellent midterm durability in patients with AF. However, the incidence of residual potentials around the pulmonary veins was not negligible.

Robotic ablation of atrial fibrillation.

Background: Pulmonary vein isolation (PVI) is an established treatment for atrial fibrillation (AF). During PVI an electrical conduction block between pulmonary vein (PV) and left atrium (LA) is created. This conduction block prevents AF, which is triggered by irregular electric activity originating from the PV. However, transmural atrial lesions are required which can be challenging. Re-conduction and AF recurrence occur in 20 - 40% of the cases. Robotic catheter systems aim to improve catheter steerability. Here, a procedure with a new remote catheter system (RCS), is presented. Objective of this article is to show feasibility of robotic AF ablation with a novel system. Materials and Methods: After interatrial trans-septal puncture is performed using a long sheath and needle under fluoroscopic guidance. The needle is removed and a guide wire is placed in the left superior PV. Then an ablation catheter is positioned in the LA, using the sheath and wire as guide to the LA. LA angiography is performed over the sheath. A circular mapping catheter is positioned via the long sheath into the LA and a three-dimensional (3-D) anatomical reconstruction of the LA is performed. The handle of the ablation catheter is positioned in the robotic arm of the Amigo system and the ablation procedure begins. During the ablation procedure, the operator manipulates the ablation catheter via the robotic arm with the use of a remote control. The ablation is performed by creating point-by-point lesions around the left and right PV ostia. Contact force is measured at the catheter tip to provide feedback of catheter-tissue contact. Conduction block is confirmed by recording the PV potentials on the circular mapping catheter and by pacing maneuvers. The operator stays out of the radiationfield during ablation. Conclusion: The novel catheter system allows ablation with high stability on low operator fluoroscopy exposure.

Robotic Ablation of Atrial Fibrillation

Background: Pulmonary vein isolation (PVI) is an established treatment for atrial fibrillation (AF). During PVI an electrical conduction block between pulmonary vein (PV) and left atrium (LA) is created. This conduction block prevents AF, which is triggered by irregular electric activity originating from the PV. However, transmural atrial lesions are required which can be challenging. Re-conduction and AF recurrence occur in 20 - 40% of the cases. Robotic catheter systems aim to improve catheter steerability. Here, a procedure with a new remote catheter system (RCS), is presented. Objective of this article is to show feasibility of robotic AF ablation with a novel system. Materials and Methods: After interatrial trans-septal puncture is performed using a long sheath and needle under fluoroscopic guidance. The needle is removed and a guide wire is placed in the left superior PV. Then an ablation catheter is positioned in the LA, using the sheath and wire as guide to the LA. LA angiography is performed over the sheath. A circular mapping catheter is positioned via the long sheath into the LA and a three-dimensional (3-D) anatomical reconstruction of the LA is performed. The handle of the ablation catheter is positioned in the robotic arm of the Amigo system and the ablation procedure begins. During the ablation procedure, the operator manipulates the ablation catheter via the robotic arm with the use of a remote control. The ablation is performed by creating point-by-point lesions around the left and right PV ostia. Contact force is measured at the catheter tip to provide feedback of catheter-tissue contact. Conduction block is confirmed by recording the PV potentials on the circular mapping catheter and by pacing maneuvers. The operator stays out of the radiationfield during ablation. Conclusion: The novel catheter system allows ablation with high stability on low operator fluoroscopy exposure.

Pulmonary vein isolation using the Rhythmia mapping system: Verification of intracardiac signals using the Orion mini-basket catheter.

During pulmonary vein isolation (PVI), a circular lasso catheter is positioned at the junction between the left atrium (LA) and the pulmonary vein (PV) to confirm PVI. The Rhythmia mapping system uses the Orion mini-basket catheter with 64 electrodes instead of the lasso catheter. However, its feasibility to determine PVI has not been studied. The purpose of this study was to compare signals between the mini-basket and lasso catheters at the LA-PV junction. In 12 patients undergoing PVI using Rhythmia, the mini-basket and lasso catheters were placed simultaneously at the LA-PV junction for baseline and post-PVI signal assessment. Pacing from both catheters was performed to examine the presence of exit block. At baseline, recordings of LA and PV potentials were concordant in all PVs. However, after PVI, concordance between the catheters was only 68%. Discordance in all cases resulted from loss of PV potentials on the lasso catheter with persistence of PV potentials on the mini-basket catheter. In 9 of 13 PVs (69%), these potentials represented true PV potentials that were exclusively recorded with the smaller and closely spaced mini-basket electrodes. In the other 4 PVs (31%), these potentials originated from neighboring structures and resulted in underestimation of PVI. The use of the mini-basket catheter alone is sufficient to determine PVI. While it improves recording of PV potentials after incomplete ablation, it is also associated with frequent recording of "PV-like" potentials originating from neighboring structures. In these cases, pacing maneuvers are helpful to determine PVI and avoid excessive ablation.

Location.

Location.

Pulmonary vein isolation for atrial fibrillation in the postpneumonectomy population: a feasibility, safety, and outcomes study.

Pulmonary vein isolation (PVI) of the remnant pulmonary vein (PV) stumps in pneumonectomy patients has not been well characterized. This is a multicenter observational study of patients with a remnant PV stump after pneumonectomy. Consecutive patients with a history of pneumonectomy and who had undergone RF ablation for drug refractory AF were identified from the AF database at the participating institutions. There were 15 patients in whom pneumonectomy was performed, for resection of tumors in 10, infection in 4, and bullae in 1 patient and who underwent RF ablation for AF. The mean age was 63 ± 7 years. The stumps were from the right lower PV in 5, left upper PV in 5, left lower PV in 3, and right upper PV in 2 patients. All the PV stumps were electrically active with PV potentials and 9 (60%) of them had triggered activity. PVI was performed in 14 and focal isolation in 1 patient. At 1-year follow-up, 80% were free of AF, off of antiarrhythmic medications. PV stumps in AF patients with previous pneumonectomy are electrically active and are frequently the sites of active firing. Isolation of these PV stumps can be accomplished safely and effectively using catheter ablation with no practical concern for PV stenosis or compromising PV stump integrity.

Simultaneous isolation of superior and inferior pulmonary veins on both the left and right sides could yield better outcomes in patients with paroxysmal atrial fibrillation.

This study investigated whether disappearance patterns of pulmonary vein (PV) potentials (PVPs) during PV isolation (PVI) affect the outcome of catheter ablation (CA) in patients with paroxysmal atrial fibrillation (PAF). Extensive PVI was performed in 1149 PAF patients (age, 61 ± 10 years). Clinical and demographic characteristics, ablation data, and follow-up outcomes were prospectively collected. During an initial CA, simultaneous disappearance of superior and inferior PVPs in both right and left PVs was observed in 464 (40.4%) patients (Group S). Atrial fibrillation-recurrence free rates at 1, 3, and 5 years after the initial CA in Group S were 78.9, 71.9, and 68.1%, respectively, which were higher than those in Group Non-S (P = 0.004). However, those were similar after the final CA between both groups. The incidence of PV-left atrium (LA) electrical reconnection was significantly lower in Group S than in Group Non-S in the second (Group S, 65.6% vs. Group Non-S, 82.1%; P = 0.004) and third (Group S, 8.3% vs. Group Non-S, 47.6%; P = 0.03) CAs. Furthermore, the reconnections more frequently occurred on the side of PVs where simultaneous PVP elimination had not been achieved at the initial CA. Simultaneous disappearance of superior and inferior PVPs in both right and left PVs independently reduced the risk of AF recurrence after the initial CA by 26%. The simultaneous disappearance of superior and inferior PVPs in both right and left PVs is associated with less frequent PV-left atrium reconnection and may yield a better clinical outcome after the initial CA.

Clinical implications of and factors influencing dissociated pulmonary vein potentials

BackgroundFactors influencing dissociated pulmonary vein (PV) potentials (DPVPs) in atrial fibrillation (AF) patients undergoing circumferential PV isolation have not been investigated. Furthermore, the clinical implications of such DPVPs remain controversial. MethodsCircumferential PV isolation as a first ablation procedure was performed in 688 consecutive patients with AF (460 men; mean age, 58.9±10.5 years). The clinical implications of and factors influencing DPVPs were evaluated. ResultsAcute PV isolation was achieved in 679 (98.7%) patients. A total of 578 (42.6%) ipsilateral PVs with DPVPs were documented in 378 (55.7%) patients (DPVPs group). Multivariate analysis revealed that male gender [odds ratio (OR): 1.894; 95% confidence interval (CI): 1.344–2.667; p<0.001] and paroxysmal AF (OR: 1.715; 95% CI: 1.182–2.488; p=0.005) were independent factors for DPVPs. The incidence of acute and intraoperative PV reconnection (PVR) was higher in the DPVPs group than in the non-DPVPs group (33.1% vs. 17.9%; p<0.001 and 44.4% vs. 28.2%; p<0.001). After the first procedure, 244 (65.6%) DPVPs-group patients and 168 (56.4%; p=0.015) non-DPVPs group patients were free from AF recurrence. During repeat procedures, PVR incidence was similar in the DPVPs group (81.8%) and non-DPVPs groups (83.3%; p=0.863). ConclusionMale gender and paroxysmal AF were independent risk factors for DPVPs in patients undergoing circumferential PV isolation. DPVPs had a significant impact on acute and intraoperative PVR. The outcomes of the first ablation procedure were better in patients with DPVPs.