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Background: Although several prognostic factors of atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) have been investigated, the accurate prediction of AF recurrence remains difficult. We propose an electrocardiogram (ECG) index, the P-wave force (PWF), which is the product of the amplitude of the negative terminal phase of the P wave in the V1 electrode and the filtered P-wave duration, obtained by a signal-averaged P-wave analysis. This study was conducted to evaluate the impact of the PWF on the recurrence of AF after PVI., Methods: We retrospectively evaluated 79 paroxysmal AF patients (64 ± 9 years, 56 males) who underwent PVI by cryoballoon ablation. Standard 12-lead ECG and a P-wave signal-averaged electrocardiogram (SAECG) were recorded the day before and 1 month after the PVI procedure., Results: During the mean follow-up of 10.2 months, AF recurred in 11 (14%) patients. The PWF 1 month after ablation was significantly higher in the recurrence group compared to that in the nonrecurrence group (8.8 ± 3.1 mVms vs 6.5 ± 2.9 mVms, P = 0.017). The patients with a PWF value ≥9.3 mVms had a significantly greater risk of recurrence after the ablation compared to the patients with a PWF value <9.3 mVms (log-rank test, P < 0.001)., Conclusion: Higher PWF after cryoballoon ablation was associated with poor prognosis during follow-up. The PWF may be a useful and noninvasive marker to predict the recurrence of AF., (© 2016 Wiley Periodicals, Inc.)

Aims: Identification of arrhythmogenic pulmonary veins (PVs) initiating atrial fibrillation is helpful for catheter ablation. The aim of this study was to examine the possibility to recognize the arrhythmogenic PV using Holter ECG., Methods and Results: In 20 patients, P-wave characteristics were studied during pacing from four PVs. Holter ECG was recorded using two leads: the modified CC5 (Lead 1) and NASA (Lead 2), and the P-wave amplitude and duration were evaluated. In Lead 1, P-waves produced by left PV pacing were significantly lower in amplitude than right PV pacing (-3 +/- 75 vs. 86 +/- 43 microV, P < 0.001). In Lead 2, pacing in superior PVs produced P-waves with higher amplitude than inferior PVs (210 +/- 74 vs. 125 +/- 66 muV, P < 0.001). The criteria proposed by the morphological characteristics of P-waves identified putative arrhythmogenic PVs with an accuracy of 78%., Conclusion: It might be possible to identify putative arrhythmogenic PVs by modified Holter ECG recording.

Background: The relationship between vagal modification and paroxysmal atrial fibrillation (PAF) recurrence after segmental pulmonary vein (PV) isolation (S-PVI) was investigated., Methods and Results: S-PVI was performed in 77 PAF patients using a multielectrode basket or circular catheter to achieve electrical disconnection of all 4 PVs independent of eliminating vagal reflexes. Serial Holter-recordings were obtained at baseline, immediately and 1, 3, 6, and 12 months after S-PVI to analyze the heart rate variability. Fifty-one patients were free from symptomatic PAF (Group A) and 26 had late PAF recurrences (Group B) at 12-month follow-up. Immediately after S-PVI, the root mean square of the successive differences (rMSSD) and high-frequency (HF) power, which reflected parasympathetic nervous activity, were significantly lower in Group A than in Group B (rMSSD: 33.6+/-26.0 vs 60.6+/-23.2 ms, P<0.05; ln HF: 8.73+/-0.84 vs 9.31+/-0.95 ms2, P<0.05). There were no significant differences in the average heart rate or ratio of the low-frequency to HF powers between the 2 groups. By multivariate analysis, only the HF immediately after S-PVI was an independent predictor of PAF recurrence (hazard ratio 1.707, 95% confidence interval 1.057-2.756, P<0.05)., Conclusions: Vagal modification after S-PVI could also help prevent late recurrence of PAF.

The atrial fibrillation (AF) recurrence rate after pulmonary vein isolation (PVI) has been relatively high and in some unsuccessful PVI cases, antiarrhythmic drugs that were ineffective before PVI may become effective (hybrid therapy). The purpose of this study was to investigate the relationship between the brain natriuretic peptide (BNP) level and the effect of the hybrid therapy. In 28 lone AF patients undergoing hybrid therapy, the plasma BNP level was measured before PVI and before and 3 months after administering an antiarrhythmic drug. Fifteen patients were free of AF after the hybrid therapy (effective group), and 13 still had recurrent AF after (noneffective group). At baseline, in all patients the BNP level was elevated, and there were no significant differences in the BNP level between the 2 groups. The BNP level was significantly decreased after PVI in the effective group (56.8 +/- 23.1 versus 37.5 +/- 16.7 pg/mL, P < 0.05) but not in the noneffective group (74.3 +/- 47.8 versus 79.7 +/- 54.4 pg/mL, NS). The elevated BNP level normalized in all effective group patients. The criterion consisting of a net value of < 60.0 pg/mL or a reduction in the BNP level of > 10.0 pg/mL after PVI predicted the effective group patients with a high accuracy. A significant reduction in the BNP level after PVI may be a useful predictor of the responders to antiarrhythmic drug therapy in patients with recurrent AF after PVI. The hybrid therapy may be effective in patients whose PVs serve as a dominant AF substrate.

Background: Pulmonary vein (PV) isolation (PVI) has been demonstrated to be an effective technique for curing atrial fibrillation (AF). AF foci that cannot be isolated by PVI (non-PV foci) can become the cause of AF recurrence. The purpose of this study was to investigate the characteristics of non-PV AF foci., Methods and Results: Two hundred consecutive patients with symptomatic AF underwent electrophysiologic studies. In all patients, successful ostial or antral PVI was achieved with a multielectrode basket catheter (MBC). In 45 patients, spontaneous AF was induced even after PVI. In 23 of those patients, 30 AF foci were found in the left atrium (LA) (12 in the PV antrum, and 18 in the LA wall). Twenty-six of those foci were eliminated by focal ablation guided by an MBC. Five of those foci (four in the PV antrum and one in the LA posterior wall) were speculated to be located epicardially because a small potential preceding the LA potential was recorded from the MBC electrodes during AF initiation at the successful ablation site where single large potentials were recorded during sinus rhythm and a longer duration of radiofrequency energy delivery was needed to eliminate them., Conclusions: MBC mapping with induction of spontaneous AF may be useful for identifying non-PV AF foci in the LA after PVI. In some of those non-PV foci, mainly around the PVI lesions, a few electrophysiologic findings suggesting an epicardial location were observed. This may be a rationale for the efficacy of extensive PV ablation.

Background: This study investigated the electrophysiologic characteristics and outcome of superior vena cava (SVC) segmental ostial isolation (SOI) in patients with SVC-initiated paroxysmal atrial fibrillation (PAF)., Methods: Ninety-five patients with PAF underwent pulmonary vein (PV) SOI using a basket catheter whether the PAF originating from PVs was observed or not. Fifteen of those patients also underwent SVC SOI in the same manner due to evidence of SVC origin PAF., Results: The SVC musculature networks and electrical connections with the atrium (multiple separate electrical connections in 10, multiple separate musculature networks with separate electrical connections in 1, and a continuous broad electrical connection in 4 SVCs) were similar to those of the PV musculature. However, the occurrence of an electrical connection recovery after SOI in patients with recurrent atrial fibrillation was lower for SVCs (25%) than PVs (58%)., Conclusions: Superior vena cava SOI appears to have a lower recurrent conduction rate than PV SOI.

Background: The dimensions and electrophysiological characteristics of the antral region of human pulmonary veins (PVs) were investigated., Methods and Results: Fifty-five consecutive patients with symptomatic paroxysmal atrial fibrillation underwent PV isolation targeting the PV antrum potentials with a 31 mm multielectrode basket catheter (MBC). The most distal and proximal electrode pairs along the MBC spline where radiofrequency ablation was carried out were identified and the longitudinal distance between those ablation sites (Ld) was measured. When the Ld was > or =6 mm, the PV antrum was defined as noncoaxial. In 56% of the left superior PVs, 42% of the right superior PVs, 63% of the left inferior PVs and 56% of the right inferior PVs, a noncoaxial PV antrum was identified. In each PV, the radiofrequency ablation delivery duration and energy to complete the PV antrum isolation were significantly larger in the PVs with a noncoaxial PV antrum than in those with a coaxial PV antrum., Conclusion: The PV antrum is noncoaxial to the PV in >50% of the PVs, a feature that may increase the complexity of the circumferential isolation technique.

Objectives: The aim of this study was to investigate the prevalence and severity of left atrial (LA) edema after pulmonary vein (PV) ablation and its effect on the cardiac function., Background: Though extensive LA catheter ablation has been demonstrated to be more effective in curing paroxysmal atrial fibrillation (PAF) than segmental ostial pulmonary vein isolation (S-PVI), it might cause life-threatening complications, including congestive heart failure associated with LA edema., Methods: Fifty patients underwent S-PVI (Group S) and 27 underwent circumferential PV antrum ablation (Group C) for drug-refractory PAF. Enhanced electron beam tomography (EBT) was performed before, 1 or 2 days after, and 1 month after the PV ablation, and transthoracic ultrasound cardiography (UCG) was performed 1 month after the PV ablation in all patients., Results: The EBT assessment revealed LA edema immediately after the PV ablation in 47 Group S patients and all Group C patients. The severity of the LA edema, number of radiofrequency applications, and amount of radiofrequency energy delivered during the PV ablation was significantly greater in Group C than in Group S. One month after the PV ablation, in all patients, the EBT assessment revealed that those edematous changes had disappeared, and the UCG assessment showed no reduction in the cardiac function., Conclusions: Left atrial edema was observed in a large portion of the patients immediately after the PV ablation, and the severity of the LA edema depended on the extent and amount of the radiofrequency energy delivered in the PV ablation. The LA edema soon disappeared naturally and did not reduce the cardiac function.

To avoid fatal complications after extensive pulmonary vein (PV) ablation, it has been proved important to comprehend the anatomic relation between the PVs and the esophagus. In 42 consecutive patients with atrial fibrillation, PV ostial isolation was performed using a basket catheter. The shortest distance and anatomic relation between the esophageal lead and PV ostium, determined by successful PV ostial isolation, was analyzed in biplane fluoroscopic views. In 18 left superior PVs (LSPVs) (43%), 13 left inferior PVs (32%) (LIPVs), and all the right PVs (group A), the shortest distance was > 10 mm in > or = 1 of the biplane fluoroscopic views. In 4 LSPVs (10%) and 2 LIPVs (5%) (group B), the shortest distance was < or = 5 mm in the fluoroscopic views. In the remaining PVs (group C), the esophagus was situated directly behind 10 LSPVs (24%) and 12 LIPVs (29%) (group C1), posteromedial to 1 LSPV (2%) and 9 LIPVs (22%) (group C2), and medial to 9 LSPVs (21%) and 5 LIPVs (12%) (group C3). The risk of esophagus-associated complications with ablation around the left PV ostia was suggested to be high in group B, very low in group A, and relatively low in group C. In group C3, extensive PV ablation might increase the risk of that complication. In conclusion, esophageal leads are useful for determining strategies for PV ablation to avoid esophagus-associated complications, because they enable comprehension of the anatomic relation between the PVs and the esophagus.

Background: How extensive should an appropriate pulmonary vein (PV) ablation be is a matter of controversy., Objective: The study's aim was to investigate the efficacy of minimally extensive PV ablation for isolating the PV antrum (PVA) with the guidance of electrophysiological parameters., Methods: Fifty-five consecutive symptomatic paroxysmal atrial fibrillation (PAF) patients underwent PV mapping with a multielectrode basket catheter (MBC). A 31-mm MBC was deployed in 3-4 PVs as proximally as possible without dislodgement, and the longitudinal PV mapping enabled us to recognize single sharp potentials formed by the total fusion of the PV and left atrial potentials around the PV ostium or the transverse activation patterns that were observed. Those potentials were defined as PVA potentials. Radiofrequency ablation was performed circumferentially targeting PVA potentials with the end point being their elimination., Results: After circumferential PVA ablation, electrical disconnection was achieved in 77% and residual PVA conduction gaps were observed in 23% of all targeted PVs. Those residual conduction gaps were mainly located at the border between ipsilateral PVs (42%) and between the left PVs and left atrial appendage (33%) and were eliminated by a mean of 3 +/- 2 minutes of local radiofrequency deliveries. During the follow-up period (11 +/- 5 months), 46 (84%) patients were free of symptomatic PAF without any anti-arrhythmic drugs. No PV stenosis or spontaneous left atrial flutter occurred., Conclusions: Electrophysiological PVA ablation with an MBC is feasible and effective for curing PAF because this minimally extensive PVA isolation technique targets the optimal sites, achieving both high efficacy and safety.

The aim of this study was to investigate whether segmental ostial catheter ablation (SOCA) designed to prevent the electrical connections (ECs) between the left atrium and pulmonary veins (PVs) might help increase the efficacy of SOCA in paroxysmal atrial fibrillation (PAF). PV mapping and successful SOCA were performed with a basket catheter in 108 consecutive patients with PAF. Radiofrequency energy was delivered using a maximum output of 30 W with a 4 mm tip catheter (group I; 47) or 40 W with an 8 mm tip catheter (group II; 61). Only in the group II patients were additional radiofrequency deliveries to the specific sites where the ECs tended to recover performed after successful SOCA. After the first procedure, PAF recurred in 47% of the group I patients and 32% of the group II patients. In all 27 patients who underwent repeat procedures, EC recoveries were observed more frequently in group I than in group II (69% versus 49%; P < 0.05). After multiple procedures, there was more freedom from PAF in group II (84%) than in group I (66%) (P < 0.05). SOCA with a higher RF power, larger tip catheter, and additional RF deliveries could achieve a more effective SOCA.

Aims: The aim of this study was to reveal the incidence, location, and cause of recovery of the electrical connections (ECs) between the left atrium and the pulmonary veins (PVs) after the segmental ostial PV isolation (PVI)., Methods and Results: Pulmonary vein mapping and successful PVI were performed using a computerized three-dimensional mapping system (QMS2trade mark) with a basket catheter in 167 PVs in 53 consecutive patients with atrial fibrillation (AF). In 14 patients with recurrent AF after PVI, the same PV mapping and isolation as in the first procedure were performed, and the PV potential maps constructed by QMS2 in two different procedures were compared. Forty-nine recovered ECs were observed in 27 PVs, and all were eliminated by a few local radiofrequency (RF) applications. Thirty-four (69%) of those ECs recovered at the edge of original ECs, and another 15 (31%) recovered at the mid-portion of the continuous broad original ECs., Conclusion: Electrical connection recovery occurred most commonly at the edges of original ECs and occasionally at the mid-portion of continuous broad original ECs after PVI probably due to tissue oedema neighbouring the segmental RF lesions. Further RF lesions at the edge of original ECs and linear ablation to the continuous broad ECs may help reduce AF recurrence.

Introduction: Pulmonary vein (PV) isolation (PVI) has been recently proposed as an effective technique to cure atrial fibrillation (AF)., Aims of the Study: The aim of this study was to investigate the efficacy of a novel technique utilizing a computerized three-dimensional mapping system (QMS2) with a multielectrode basket catheter (MBC) for PVI and to reveal the relation between the style of breakthrough and the network of the PV musculature., Methods: Sixty-five consecutive patients with frequent AF attacks underwent PV mapping with a 31-mm MBC, and a three-dimensional color animation of the potential map was constructed by the QMS2. The animation color schema was arranged to minimize the low-amplitude left atrial (LA) potentials and emphasize the high-amplitude PV potentials (PVPs). The longitudinal PVP map enabled us to recognize the true breakthroughs and reveal the network of the PV musculature., Results: A total of 205 PVs (65 left superior PVs, 65 right superior PVs, 57 left inferior PVs and 18 right inferior PVs) were mapped and successful PVI was achieved in all PVs, except one that had no PVPs, with a mean radiofrequency duration of 7 +/- 5 minutes per PV. In about 90% of the PVs, a final radiofrequency application eliminated all the distal PVPs simultaneously because the PVI was performed at the appropriate LA-PV junction. A single segmental breakthrough was detected in 17 PVs, single broad breakthrough in 83 PVs, multiple separate breakthroughs with a distal connection between the PV musculatures extending from each separate breakthrough in 88 PVs and multiple separate breakthroughs without that connection in 16 PVs. During the follow-up period, fifty-one (78%) patients were free of symptomatic AF without any antiarrhythmic drugs after multiple procedures (thirty-three (51%) of those patients after the first procedure) and no PV stenosis was found., Conclusions: Computerized three-dimensional potential mapping can be useful for PVI because it can not only identify the true breakthrough, but can also confirm the elimination of the breakthroughs by the change in the activation sequence through the network of the PV musculature.

Objectives: The purpose of this study was to investigate the efficacy of a novel catheter mapping technique for predicting atrial fibrillation (AF) foci., Background: Most AF originates from pulmonary veins (PVs), but some originate from the right atrium., Methods: We developed an algorithm by correlating the cardiac recordings obtained from multielectrode catheters placed in the posterior right atrium (RA) and esophagus during pacing from the PVs and superior vena cava (SVC) or crista terminalis (CT) in 10 AF patients. We tested the algorithm's accuracy prospectively in 46 AF patients., Results: During pacing from the left PVs, the esophageal potentials preceded all other potentials. During pacing from both the right PVs and SVC-CT, the first component (FP) of the double potential (DP) recorded in the posterior RA preceded all other potentials. The amplitude of the FP was higher than that of the second DP component during pacing from the SVC-CT, whereas the reverse occurred from the right PVs. The activation sequence of the FPs and esophageal potentials was from superior to inferior during pacing from the superior PVs, whereas the reverse occurred from the inferior PVs. The accuracy of predicting 34 foci in the right PVs, 28 foci in left PVs, and 6 foci in SVC-CT was 100% for all, respectively. The accuracy of discriminating foci in the superior PVs from those in the inferior PVs was 97% in the right PVs and 96% in the left PVs., Conclusions: The technique using mapping catheters placed in the posterior RA and esophagus is feasible and effective for mapping and ablating AF.

Background: The left atrial appendage (LAA) is one of the major sources of focal atrial tachycardias (ATs).Objective: The purpose of this study was to investigate the detailed electrophysiologic characteristics and catheter ablation of focal ATs originating from the LAA.Methods: The study population consisted of 47 consecutive patients with 50 focal ATs originating from the left atrium (LA): LAA in 13, left pulmonary veins (PVs) in 14, right PVs in 12, and mitral annulus in 11. Programmed electrical stimulation and pharmacologic testing were performed to examine the mechanism of LAA AT. Left atriography was performed prior to radiofrequency ablation to identify the focus in the LAA.Results: The mechanism of LAA AT was automaticity in 11 and triggered activity in 2. The 13 LAA foci were located mainly at the LAA base: 11 on the medial side and 2 on the lateral side. Atrial activation sequences within the distal coronary sinus were helpful in differentiating these LAA foci. The criterion of a negative P wave in leads I and aVL indicating an LAA AT focus was associated with sensitivity of 92.3%, specificity 97.3%, positive predictive value 92.3%, and negative predictive value 97.3%. No complications occurred in any of the 13 patients. All 13 patients were free of atrial arrhythmias without any antiarrhythmic drugs during follow-up of 8 +/- 3 years.Conclusion: LAA ATs have typical electrophysiologic and electrocardiographic characteristics that are helpful in guiding radiofrequency catheter ablation. [ABSTRACT FROM AUTHOR]

Double Potentials Can Predict AT Foci . Introduction: The right pulmonary veins (RPVs) and posterior wall of the right atrium (PRA) are anatomically located adjacent to each other. The aim of this study was to demonstrate the electrophysiologic characteristics of atrial tachycardia (AT) originating from the PRA or RPVs. Methods and Results: A total of 26 consecutive patients with AT originating from the RPVs or PRA underwent detailed atrial endocardial mapping and successful radiofrequency catheter ablation. Eight foci were found in the PRA and 18 foci in the RPVs. Analysis of P wave configuration showed that lead V 1 was the most helpful in distinguishing the AT foci between these two sites. In all cases, double potential (DP) configurations were recorded from several electrodes of a multielectrode catheter placed in the PRA, and the first DP component (FP) was the earliest potential recorded from the right atrium during the tachycardia. The amplitude of the FP was higher than that of the second DP component (SP) for AT foci originating in the PRA, whereas the reverse occurred for those in the RPV. The activation sequence of the FP was from superior to inferior for the AT foci in the superior RPV, whereas the reverse occurred for the AT foci in the inferior RPV. Conclusion: P wave configuration in lead V 1 is helpful in distinguishing AT foci between those originating in the PRA and RPVs. The DPs obtained from the PRA can be useful in predicting whether AT foci originate from the PRA or RPVs. (J Cardiovasc Electrophysiol, Vol. 15, pp. 745-751, July 2004) [ABSTRACT FROM AUTHOR]