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Background: Open‐window mapping (OWM) is a novel automated mapping method for catheter ablation of an accessory pathway (AP), in which the local signal is annotated with window‐of‐interest parameters to analyze both atrial and ventricular signals. This study aimed to determine the utility of OWM in visualizing the location and width of APs in patients with Wolff‐Parkinson‐White syndrome. Methods: This two‐center study enrolled 30 patients (20 males; mean age: 56 years, interquartile range [IQR]: 22–69 years) who underwent high‐density OWM with the extended early‐meets‐late (EEML) algorithm using a 20‐electrode, 5‐spline catheter (PENTARAY, Biosense Webster). The lower threshold of the EEML was set to adjust the EEML gap to match the propagation mapping, and broad APs were defined as an EEML gap > 1 cm. Results: The median mapping points, mapping time, and lower threshold of the EEML were 2482 (IQR: 1755–4000) points, 23 (IQR: 15–30) min, and 23 (IQR: 18–25), respectively. All 30 APs (24 in the mitral annulus and 6 in the tricuspid annulus) were successfully eliminated. Of these APs, 21 (70%) were eliminated by the first radio frequency (RF) application. OWM revealed broad APs in 11 patients (37%), in four of whom (36%) the first RF application achieved a loss of AP conduction (vs. 90% of patients without broad APs; p =.004). Conclusion: OWM facilitates the visualization of the location and width of APs, which may be particularly useful for predicting whether multiple RF applications are required for broad APs. [ABSTRACT FROM AUTHOR]

Introduction: The left atrial (LA) posterior wall (LAPW) has been targeted to improve the clinical outcomes in patients with persistent atrial fibrillation (PersAF). This study aimed to investigate the feasibility, safety, and clinical implications of cryoballoon (CB) applications on the LAPW to accomplish electrical isolation (EI) of the LAPW with CB. Methods: A total of 100 patients (males, 84; mean age, 64 ± 10 years) with PersAF were enrolled. The first 50 patients underwent only pulmonary vein isolation (PVI) (PVI‐only group) and the remaining 50 patients underwent PVI and EI of the LAPW with CB (EI‐LAPW group). Results: One‐year sinus rhythm maintenance probability was significantly higher in the EI‐LAPW group than in PVI‐only group (80.0% vs 55.1%, P = 0.01). The success rate of constructing an LA roof block line (LA‐RB), bottom block line, and EI of the LAPW was 92%, 60%, and 58%, respectively. The nadir CB temperature (−45°C ± 4°C vs −39°C ± 5°C, P = 0.005) and anatomical angle of the left atrial roof (106°C ± 30°C vs 144°C ± 17°C, P < 0.001) significantly predicted the successful LA‐RB construction. The left ventricular ejection fraction was significantly higher in unsuccessful cases than in successful cases of an EI of the LAPW (64% ± 8% vs 58% ± 11%, P = 0.041). Even though the EI of the LAPW was unsuccessful, CB freezing in LAPW significantly debulked the nonscar area (≥0.1 mV) in LAPW (18.1 ± 5.6 vs 2.2 ± 3.1 cm 2, P < 0.001) and provided the equivalent 1‐year outcome of successful cases (79.3% vs 81.0%, P = 0.90). Conclusion: The combination of PVI and EI of the LAPW with CB provided better clinical outcomes than conventional PVI procedure for patients with PersAF. [ABSTRACT FROM AUTHOR]

Background: Little is known about the long-term outcome and recurrent form recurrence after catheter ablation of atrial fibrillation (AF) in patients with long-standing persistent AF. Methods: Two hundred thirty-six patients with persistent AF (193 men; age, 61.5±10.7 years) were enrolled, and were classified according to the duration of AF: AF duration of <1 year (group A, n=99), between 1 to 5 years (group B, n=101), and ≥5 years (group C, n=36). The long-term recurrence rate and recurrent form were compared among the groups. Results: During a median follow-up of 3.7 years, the recurrence rate was significantly worse in group C after the index and multiple procedures (Log-Rank, both for a P<0.001 in comparison to group A). In the multivariate analysis, the duration was an independent predictor of an arrhythmia recurrence (HR, 1.206; 95%CI, 1.053 to 1.381; P=0.007). Recurrent AF became permanent in 8 patients (3.4%), which was not associated with a difference in the groups (Log-rank, P=0.055), while antiarrhythmic drugs (AADs) were continued in 70% of the recurrent patients. Conclusions: Despite a high AF recurrence rate in the patients with an AF duration of ≥5 years, the majority of the patients with recurrence who continued on AADs had a paroxysmal form of AF. Catheter ablation and concomitant AADs may be effective in reducing the AF burden in such patients with an advanced AF disease stage. [ABSTRACT FROM AUTHOR]

We present a case of a 49-year-old man who experienced invariably reproducible paroxysmal supraventricular tachycardia during swallowing. Because beta-blockers and multiple antiarrhythmic drugs failed to prevent the episodes of this tachycardia, we performed catheter mapping and ablation. After placing multiple decapolar catheters, when the patient swallowed a few sections of an orange, intracardiac mapping revealed atrial premature beats and atrial tachycardia that lasted for a few seconds and arose from an ostial site of the right superior pulmonary vein. After the right superior pulmonary vein antrum was completely isolated, the patient became free from the swallowing-induced tachycardia. [ABSTRACT FROM AUTHOR]

Introduction: Most idiopathic nonreentrant ventricular tachycardia (VT) and ventricular premature contractions (VPCs) arise from the right or left ventricular outflow tract (OT). However, some right ventricular (RV) VT/VPCs originate near the His-bundle region. The aim of this study was to investigate ECG characteristics of VT/VPCs originating near the His-bundle in comparison with right ventricular outflow tract (RVOT)-VT/VPCs. Methods and Results: Ninety RV-VT/VPC patients underwent catheter mapping and radiofrequency ablation. ECG variables were compared between VT/VPCs originating from the RVOT and near the His-bundle. Ten patients had foci near the His-bundle (HIS group), with the His-bundle local ventricular electrogram preceding the QRS onset by 15–35 msec (mean: 22 msec) and His-bundle pacing produced a nearly identical ECG to clinical VT/VPCs. The HIS group R wave amplitude in the inferior leads (lead III: 1.0 ± 0.6 mV) was significantly lower than that of the RVOT group (1.7 ± 0.4 mV, P < 0.05). An R wave in aVL was present in 6 of 10 HIS group patients, while almost all RVOT group patients had a QS pattern in aVL. Lead I in HIS group exhibited significantly taller R wave amplitudes than RVOT group. HIS group QRS duration in the inferior leads was shorter than that of the RVOT group. Eight of 10 HIS group patients exhibited a QS pattern in lead V1 compared to 14 of 81 RVOT group patients. HIS group had larger R wave amplitudes in leads V5 and V6 than RVOT group. Conclusion: VT/VPCs originating near the His-bundle have distinctive ECG characteristics. Knowledge of the characteristic QRS morphology may facilitate catheter mapping and successful ablation. [ABSTRACT FROM AUTHOR]

Background: Radiofrequency catheter ablation (RFCA) can eliminate most idiopathic repetitive monomorphic ventricular tachycardias (RMVTs) originating from the right and left ventricular outflow tracts (RVOT, LVOT). Here, we describe the electrophysiological (EP) findings of a new variant of RMVT originating from the mitral annulus (MAVT). Methods and Results: MAVT was identified in 35 patients out of 72 consecutive left ventricular RMVTs from May 2000 to June 2004. All patients underwent an EP study and RFCA. The sites of origin of the MAVT were grouped into four groups according to the successful ablation sites around the mitral annulus. Group I included the anterior sites (n = 11), group II the anterolateral sites (n = 9), group III the lateral sites (n = 6), and group IV the posterior sites (n = 9). The MAVTs were a wide QRS tachycardia with a delta wave-like beginning of the QRS complex. The transitional zone of the R wave occurred between V1-V2 in all cases. The 12-lead electrocardiogram (ECG) pattern might reflect the site of the origin of MAVTs around the mitral annulus. We proposed an algorithm for predicting the site of the focus and the tactics needed for successful RFCA of the MAVT. Conclusions: We described the EP findings of the new variant of RMVT, MAVT. Most MAVTs could be eliminated by RF applications to the endocardial mitral annulus using our proposed tactics. [ABSTRACT FROM AUTHOR]

Introduction: Recent studies have reported the efficacy of the cryoballoon (CB)‐guided left atrial roof block line (LARB) creation in patients with persistent atrial fibrillation (AF). However, it can be technically challenging to attach the balloon to the left atrial (LA) roof due to its anatomical variations. We designed a new procedure called the "Raise‐up Technique," which may facilitate the firm adhesion of the CB to the LA roof during freezing. This study aimed to evaluate the efficacy of the Raise‐up technique in LARB creation. Methods and Results: In total, 100 consecutive patients with persistent AF who underwent CB‐LARB creation were enrolled. Fifty‐seven patients underwent LARB creation using the Raise‐up technique (Raise‐up group), and the remaining 43 did not use it (control group). The Raise‐up technique was performed as follows: An Achieve catheter was inserted as deeply as possible into the upper branch of the right superior pulmonary vein to anchor the CB. The balloon was placed below the targeted site on the LA roof and frozen. When the temperature of the CB reached approximately −10°C and the CB was easier to attach to the LA tissue, the CB was raised and pressed against the LA roof immediately by sheath advancement. Then the balloon could be in firm contact with the target site on the roof. If necessary, additional sheath advancement after sufficient freezing (−20°C to −30°C) was allowed the CB to have more firm and broad contact with the target site. LARB creation without touch‐up ablation was achieved in 54 of 57 patients (94.7%) in the Raise‐up group and 33 of 43 patients (76.7%) in the control group (p <.05). The lesion size of the LARB in the Raise‐up group was significantly larger than that in the control group (15.2 cm2 vs. 12.8 cm2, p <.05). Moreover, the width of the LARB lesion in the Raise‐up group was wider than that in the control group (32.0 mm vs. 26.6 mm, p <.05). Conclusion: The Raise‐up technique enabled the creation of seamless and thick LARB lesions with a single stroke. In addition, the CB‐LARB lesions created using the Raise‐up technique tended to be large, resulting in extensive debulking of the LA posterior wall arrhythmia substrates. In CB ablation for persistent AF, the Raise‐up technique can be considered one of the key strategies for LARB creation. [ABSTRACT FROM AUTHOR]

This case report describes frequent ventricular premature contractions (VPCs) originating from an epicardial site of the basal posteroseptal ventricle. Detailed pace-mapping using a high output pacing stimulator was utilized to successfully ablate VPCs within the coronary sinus. [ABSTRACT FROM AUTHOR]

Introduction: Dual atrioventricular nodal non‐reentrant tachycardia (DAVNNT) is a rare and challenging‐to‐diagnose arrhythmia, without previous reports associating it with a leftward inferior extension (LIE). Methods: Diagnosis was made using adenosine triphosphate (ATP) injection during atrial pacing in a suspected DAVNNT patient. Results: Ablation of the rightward inferior extension was unsuccessful in eliminating DAVNNT; however, subsequent ablation of the LIE successfully eradicated the arrhythmia. Conclusion: This unique case, marked by the first instance of DAVNNT caused by LIE, diagnosed through ATP injection, underscores the utility of this diagnostic approach and broadens the spectrum of our understanding and management of this condition. [ABSTRACT FROM AUTHOR]

Introduction: The major limitation of the current cryoballoon (CB) system is a fixed 28 mm balloon‐size. We sought to analyze real‐world early experience with novel‐sized adjustable CB. Methods: This multicenter observational study included 140 consecutive atrial fibrillation patients (71 years, 94 men, 86 paroxysmal) who underwent pulmonary vein (PV) isolation using expandable diameter CB capable of ablation at 28 or 31 mm. Results: Out of 544 targeted PVs, 526 (96.7%) were successfully isolated by a size‐adjustable CB with a 770 [690−870] second median application dose, while the remaining 18 required touch‐up ablation. Among them, 326 (62.0%) PVs were isolated by a 31 mm balloon, and the rate was significantly higher for upper than lower PVs (73.0% vs. 45.7%, p <.0001) and highest for right superior (78.5%) and lowest for right inferior (39.9%) PVs. The biophysical parameters and time to isolation were comparable between the 28 and 31 mm balloons, however, the real‐time PV potential monitoring capability was significantly higher for 31 mm than 28 mm balloons for the left superior PV. The esophageal temperature reached 15°C during left inferior PV ablation significantly more often with 31 mm than 28 mm balloons (43.1% vs. 18.2%, p =.008). Right phrenic nerve injury (PNI) occurred in 9 (6.4%) patients during applications (6 right superior, 2 right inferior PVs), and most occurred with a 31 mm balloon. Conclusions: Our real‐world early data demonstrated high acute efficacy and safety of the novel‐sized adjustable CB. The biophysical parameters were similar between the 28 and 31 mm balloons. No marked decrease in the incidence of PNI was observed even with 31 mm balloons. [ABSTRACT FROM AUTHOR]

Introduction: Cryoballoon ablation (CBA) of the left atrial (LA) roof in addition to a pulmonary vein isolation has been expected to improve the clinical outcomes post‐atrial fibrillation (AF) ablation. We demonstrated the characteristics and efficacy of CBA of the LA roof through our experience with a large volume of procedures. Methods: Among 1036 AF ablation procedures with CBA of the LA roof, 834 patients who underwent a de novo ablation were analyzed. Results: Complete LA roof line conduction block was obtained in 767 patients (92.0%) solely by CBA (Group A). Compared with the other patients (Group B), the mean nadir balloon temperature during CBA of the LA roof (−44.5 ± 5.6°C for Group A vs. −40.5 ± 7.5°C for Group B, p <.01) and number of cryoballoon applications during the LA roof ablation with a circular mapping catheter located in the left superior pulmonary vein (1.3 ± 0.8 for Group A vs. 1.6 ± 1.0 for Group B, p =.02) were significantly lower in Group A. A multivariate analysis revealed that those were predictors of a complete LA roof conduction block after only CBA. The 1‐year Kaplan–Meier atrial arrhythmia free rate estimates were 80.6% for Group A and 59.0% for Group B (p <.01). Conclusion: Complete LA roof line conduction block could be obtained with a cryoballoon without touch‐up ablation in most cases. The LA roof CBA with a circular mapping catheter located in the right superior pulmonary vein was preferable to obtaining complete LA roof conduction block, which was important with regard to the clinical outcomes. [ABSTRACT FROM AUTHOR]

Backgrounds: Catheter ablation for non‐paroxysmal atrial fibrillation (non‐PAF) remains challenging and more effective strategy has been required to reduce postoperative arrhythmia recurrences. This study aims to investigate the efficacy and safety of a novel extensive ablation strategy for non‐PAF, that is based on a combination of cryoballoon (CBA), radiofrequency (RFA), and Marshall‐vein ethanol ablations (EA‐VOM). Methods: The study was a single‐center, retrospective observational study. We enrolled 171 consecutive patients who underwent de‐novo catheter ablation for non‐PAF under conscious sedation with a novel extensive ablation strategy that included CBA for pulmonary vein isolation (PVI) and left atrial roof ablation (LARA), RFA for mitral isthmus (MI) ablation, superior vena cava isolation, and other linear ablations and EA‐VOM. Recurrence of atrial arrhythmias over 1 year, procedure outcomes, and procedure‐related complications were investigated. Results: A total of 139 (81.3%) patients remained in sinus rhythm during 1‐year follow‐up. Of the 139 patients, 51 patients (29.8%) received antiarrhythmic drugs. The mean procedure time was 204 ± 45 min. PVI and LARA ablation by CBA and MI block by RFA and EA‐VOM were completed in 171 (100%) and 166 (97.1%) patients, respectively. No serious procedure‐related complications were observed except for one case of delayed pericardial effusion. Conclusion: Approximately 80% of the study patients were AF‐free during 1‐year follow‐up period after a single procedure based on the novel extensive ablation strategy combining CBA, RFA, and EA‐VOM. This strategy for non‐PAF may be preferred in terms of maintenance of sinus rhythm, safety even in high‐risk patients, and relatively short procedure time. [ABSTRACT FROM AUTHOR]

Introduction Pulmonary vein isolation (PVI) using a cryoballoon (CB) is a useful tool for treating atrial fibrillation (AF); however, the clinical efficacy of the CB has never been fully investigated in patients with a left common pulmonary vein (LCPV). Methods and results Three hundred twenty-four consecutive paroxysmal AF patients underwent PVI with a CB. Three-dimensional computed tomography was performed in all patients before the ablation. The clinical outcomes of the AF ablation between patients with (Group A) and without an LCPV (Group B) were compared. An LCPV was observed in 27 (8%) patients. There were no significant differences in the procedure time (149 ± 45 min vs. 143 ± 40 min, respectively; P = 0.42) and percentage needing touch up ablation between the 2 groups (26% vs. 20%, respectively; P = 0.45). At a mean follow-up of 454 ± 195 days, 282 of 324 (87%) patients were free from any atrial tachyarrhythmias (ATs) after a single procedure. Twenty out of 27 (74%) Group A patients and 262 of 297 (88%) Group B patients were free from ATs (15-month Kaplan-Meier event free rate estimates, 77% and 89%, respectively; P = 0.02). A multivariate analysis identified the presence of an LCPV and the left atrial diameter as reliable predictors of recurrent ATs. Conclusions The long-term clinical outcomes of ablation of AF with the CB was worse in patients with an LCPV than in those without. The presence of an LCPV and the LA size seemed to be reliable predictors of a worse outcome. [ABSTRACT FROM AUTHOR]

We report a case in which endocardial radiofrequency (RF) ablation guided by unipolar intracoronary mapping using a guidewire was an effective therapy for treating VT originating from an epicardial site of the left ventricle. A 55-year-old man with dilated cardiomyopathy was referred for treatment of refractory sustained monomorphic VT. The earliest unipolar electrogram with a near-perfect pace map was identified at segment #8 of the left anterior descending artery utilizing a guidewire through a microtube catheter during the VT. VT was terminated by an endocardial RF application at an upper midventricular septal site that did not have a good pacemap or the earliest electrogram, and that was the most adjacent anatomical endocardial site to the guidewire tip. No VT was clinically observed during a follow up period of 14 months. [ABSTRACT FROM AUTHOR]

Introduction: Radiofrequency catheter ablation (RFCA) of severely symptomatic monomorphic ventricular premature beats (VPBs) is reported to be a safe and effective treatment option. However, the chronic hemodynamic effects of these VPBs have not been precisely evaluated. Methods and Results: We sought to investigate chronic effects after decreasing the number of VPBs by RFCA. A total of 47 patients who had no underlying heart disease and frequent monomorphic VPBs, consisting of more than 10,000 beats per day (24,194 ± 12,516 beats per day), were enrolled. Patients were treated with RFCA and followed up over 6 months as outpatients. Echocardiography and serum B-type natriuretic peptide (BNP) level were repeatedly checked before and after RFCA. In 38 patients, whose VPBs were dramatically decreased to less than 1,000 beats per day by successful RFCA, left ventricular (LV) end-diastolic dimension (LVEDd) and end-systolic dimension (LVESd) measured by echocardiography decreased significantly (LVEDd: 50 ± 5 to 48 ± 5 mm, P < 0.01; LVESd: 33 ± 7 to 30 ± 6 mm, P < 0.01) in association with improvement of BNP level (39.9 ± 34.1 to 16.8 ± 10.3 pg/mL, P = 0.0001). In nine patients, whose VPBs were treated unsuccessfully by RFCA or that recurred, LV dimensions and BNP level did not change during the follow-up period. Conclusion: Significant improvement in LV dimensions and serum BNP level appeared to indicate that RFCA of VPBs ameliorated occult cardiac dysfunction induced by frequent VPBs. [ABSTRACT FROM AUTHOR]

Background: Contrast computed tomography (CT) is a useful tool for the detection of intracardiac thrombi. We aimed to assess the accuracy of the late‐phase prone‐position contrast CT (late‐pCT) for thrombus detection in patients with persistent or long‐standing persistent atrial fibrillation (AF). Methods: Early and late‐phase pCT were performed in 300 patients with persistent or long‐standing AF. If late‐pCT did not show an intracardiac contrast defect (CD), catheter ablation (CA) was performed. Immediately before CA, intracardiac echocardiography (ICE) from the left atrium was performed to confirm thrombus absence and the estimation of the blood velocity of the left atrial appendage (LAA). For patients with CDs on late‐pCT, CA performance was delayed, and late‐pCT was performed again after several months following oral anticoagulant alterations or dosage increases. Results: Of the 40 patients who exhibited CDs in the early phase of pCT, six showed persistent CDs on late‐pCT. In the remaining 294 patients without CDs on late‐pCT, the absence of a thrombus was confirmed by ICE during CA. In all six patients with CD‐positivity on late‐pCT, the CDs vanished under the same CT conditions after subsequent anticoagulation therapy, and CA was successfully performed. Furthermore, the presence of residual contrast medium in the LAA on late‐pCT suggested a decreased blood velocity in the LAA (≤ 15 cm/s) (sensitivity = 0.900 and specificity = 0.621). Conclusions: Late‐pCT is a valuable tool for the assessment of intracardiac thrombi and LAA dysfunction in patients with persistent or long‐standing persistent AF before CA. [ABSTRACT FROM AUTHOR]

Introduction: Pulmonary vein isolation (PVI) and linear ablation with a roof line and bottom line on the left atrial (LA) posterior wall (LAPW) can be achieved with a cryoballoon (CB). This study sought to investigate the long‐term durability of these linear lesions. Methods and results: Among 290 persistent patients with atrial fibrillation (AF) who had undergone linear ablation with a CB on the roof and bottom line of the LAPW in addition to the PVI, we analyzed those patients who underwent a re‐do AF ablation. Arrhythmia recurrence was confirmed in 70 (24%) out of 290 patients, and 47 (16%) patients underwent re‐do sessions. At the beginning of the re‐do ablation, we examined the reconnection sites of the linear lesions on the LAPW and PVI. Maintenance of the conduction block on the LAPW roof and bottom lines was observed in 35 out of 47 patients (74.5%), and 16 out of 35 patients (45.7%), respectively. The length of the roof line was significantly shorter in patients with preservation of the conduction block on the LAPW roof than in those without (36.2 ± 6.5 mm vs 41.6 ± 4.7 mm, P =.02). Conclusion: Durable lesions could be obtained after linear ablation with the CB for the LAPW roof line, especially in those with a relatively short LAPW roof line. However, patients requiring touch‐up ablation with radiofrequency were included, and that was associated with a potential financial implication. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to test regional pharmacological effects of an antiarrhythmic agents to predict ablative effects. Background: The vein of Marshall (VOM) providing vascular access to myocardial tissue has been used for ablative purposes using ethanol. Methods: A total of 35 patients (male 21, 63.2 ± 7.8 years old) were included. A balloon‐tipped infusion catheter was inserted into the VOM. Endocardial ultrahigh‐resolution mapping was performed along the VOM region to record the change in atrial electrograms (AEs) after VOM injection of cibenzoline of 3.5 mg during sustained atrial fibrillation (AF). Subsequently, ethanol was infused into the VOM and ablative region was mapped. Results: In 17 patients (49 %), cibenzoline reduced AEs amplitude by >50%, all of which had also complete elimination of AEs following ethanol (Group A). In 18 patients (Group B), cibenzoline failed to eliminate AEs; yet, in 13 of 18 AEs were eliminated by ethanol. In the remaining five patients, ethanol did not eliminate AE. Conclusions: Cibenzoline into the VOM could reliably predicts the results of subsequent ethanol infusion into the VOM using ultrahigh‐resolution mapping system, which leads to avoid unnecessary permanent lesion creation by ethanol infusion. [ABSTRACT FROM AUTHOR]

As different from radiofrequency current energy, cryofreezing energy is able to provide reversible effects on cardiac tissue, called "cryomapping," which enables us to predict the effects of a subsequent application of ablative energy. Cryomapping is able to delineate the anatomical location of the lower common pathway of atrioventricular nodal reentrant tachycardia. [ABSTRACT FROM AUTHOR]

Introduction: Adenosine triphosphate (ATP) sensitive atrial tachycardia (AT) has been treated by radiofrequency catheter ablation. Cryofreezing energy has emerged as a novel energy source for catheter ablation. The aim of this study was to investigate the efficacy and safety of cryofreezing ablation for ATP‐sensitive AT. Methods and Results: A total of six patients with ATP‐sensitive ATs were included in this study. A single atrial extrastimulation was able to initiate and terminate these ATs in all six patients. The electrophysiological findings satisfied the diagnostic criteria of ATP‐sensitive AT. The ablation catheter was located at the earliest activation site of atrial excitation during the AT, and cryofreezing energy was delivered through a cryoablation catheter to perform cryomapping at temperature of −30 or −80°C. When cryomapping successfully terminated the ATs, cryoablation at a temperature of −80°C was subsequently performed. The earliest atrial activation during AT was recorded at the Koch's triangle area associated with a distinct intra‐atrial activation sequence from that recorded during ventricular pacing. Cryoablation was performed at successful cryomapping sites and resulted in the complete elimination of the AT in all six patients without affecting the bidirectional atrioventricular (AV) nodal conduction. Conclusion: Cryofreezing energy was safe and effective in treating ATP‐sensitive ATs even in patients with its origins located in the vicinity of the AV node. [ABSTRACT FROM AUTHOR]

Background: The cryoballoon (CB) can be utilized for extra pulmonary vein (PV) ablation such as for a left atrial (LA) posterior wall (LAPW) isolation. However, scrutiny of the esophageal injuries during the LAPW isolation has never been performed. We sought to thoroughly investigate the esophageal lesions (ELs) and gastric hypomotility (GH) caused by an LAPW isolation using a CB. Methods: A total of 101 persistent atrial fibrillation patients who underwent an LAPW isolation using a CB were enrolled. The CB was applied on the roof and bottom area of the LAPW after a PV isolation. The luminal esophageal temperature (LET) was monitored by a thermistor probe during the CB applications. When the LET reached 15°C, the freezing application was prematurely interrupted. Esophagogastroscopy was performed on the next day following the ablation. Results: All PVs were successfully isolated in all patients. A successful LAPW isolation solely with CB ablation was performed in 72 (71.3%) patients. Cryofreezing applications were prematurely interrupted due to low LETs in 49 (48.5%) patients predominantly during the LA bottom line ablation. ELs and GH were observed in 11 (10.9%) and 16 patients (15.8%), respectively. The nadir LET tended to be lower in patients with ELs and GH than in those without (ELs: 14.8 ± 4.5°C vs 17.4 ± 6.0°C, P = 0.17; GH: 15.5 ± 4.5°C vs 17.5 ± 6.1°C, P = 0.23, respectively). Conclusions: Esophageal complications such as ELs and GH occur during the LAPW isolation with a CB. There was no reliable predictor of those adverse events. [ABSTRACT FROM AUTHOR]

Background: Point-by-point catheter ablation is an established treatment for drug-refractory paroxysmal atrial fibrillation (PAF). However, it is time consuming, requires excellent technique to achieve complete pulmonary vein (PV) isolation, and is associated with severe complications.Objectives: The purpose of this study was to evaluate the safety and effectiveness of a HotBalloon ablation (HBA) compared with antiarrhythmic drug therapy (ADT) for the treatment of PAF.Methods: A prospective multicenter randomized controlled study was conducted in Japan. Patients with symptomatic PAF refractory to antiarrhythmic drugs (Class I to IV) were randomized to HBA or ADT at a 2:1 ratio and assessed for effectiveness in a comparable 9-month follow-up period.Results: A total of 100 patients in the HBA group and 43 patients in the ADT group received treatment at 17 sites. HBA procedure produced acute complete PV isolation in 98.0% (392 of 400) of the PVs and in 93.0% (93 of 100) of patients in the HBA group. The chronic success rates after the 9-month effective evaluation period were 59.0% in the HBA group (n = 100) and 4.7% in the ADT group (n = 43; p < 0.001). The incidence of major complications was 11.2% (15 of 134 patients). The incidences of PV stenosis (>70%) and transient phrenic nerve injury were 5.2% and 3.7%, respectively. The mean fluoroscopy time was 49.4 ± 26.6 min (n = 134), and the mean procedure duration was 113.9 ± 31.9 min (n = 133).Conclusions: This study demonstrates the superiority of HBA compared with ADT for treatment of patients with PAF, and a favorable safety profile. [ABSTRACT FROM AUTHOR]

Background: Despite similar QRS morphology, idiopathic repetitive monomorphic ventricular tachyarrhythmias (VTs) of left ventricular outflow tract (LVOT) are known to have the variants of different adjacent origins, including the aorto-mitral continuity (AMC), anterior site around the mitral annulus (MA), aortic sinus cusps (ASC), and epicardium. However, the electrocardiographic characteristics of those variants previously have not been evaluated fully. Methods and Results: Based on the mapping site and successful ablation in 45 consecutive patients with LVOT-VTs, we classified them into VTs of AMC (n = 3), MA (n = 8), ASC (n = 32), and epicardial (n = 2) origins. In all patients, we performed activation mapping and an electrocardiographic analysis. All AMC-VTs patients had monophasic R waves in almost all the precordial leads, while those with anterior MA-VTs had an Rs pattern in some precordial leads except for lead V6, and those with ASC-VTs had a variable transitional zone in leads V1–4. There was no S wave in lead V6 in any group except for one patient with anterior MA-VTs. The intrinsicoid deflection time in the AMC-VTs patients and anterior MA-VTs patients was significantly greater than in those with ASC-VTs (P < 0.05). There was no significant difference in the R-wave amplitude in the inferior leads among the groups. Successful radiofrequency catheter ablation (RFCA) was achieved in all patients except for in those with epicardial origin VT. Conclusions: Despite many morphological similarities, the LVOT-VTs originating from the AMC, anterior MA and ASC could be identified by our proposed electrocardiographic characteristics in order to safely perform RFCA. [ABSTRACT FROM AUTHOR]

Objectives: We investigated the electrocardiographic (ECG) and electrophysiologic characteristics of ventricular tachycardia (VT) originating within the pulmonary artery (PA). Background: Radiofrequency catheter ablation (RFCA) is routinely applied to the endocardial surface of the right ventricular outflow tract (RVOT) in patients with idiopathic VT of left bundle branch block morphology. It was recently reported that this arrhythmia may originate within the PA. Methods: Activation mapping and ECG analysis were performed in 24 patients whose VTs or ventricular premature contractions (VPCs) were successfully ablated within the PA (PA group) and in 48 patients whose VTs or VPCs were successfully ablated from the endocardial surface of the RVOT (RV-end-OT group). Results: R-wave amplitudes on inferior ECG leads, aVL/aVR ratio of Q-wave amplitude, and R/S ratio on lead V2 were significantly larger in the PA group than in the RV-end-OT group. On intracardiac electrograms, atrial potentials were more frequently recorded in the PA group than in the RV-end-OT group (58% vs. 12%; p < 0.01). The amplitude of local ventricular potentials recorded during sinus rhythm within the PA was significantly lower than that recorded from the RV-end-OT (0.62 ± 0.56 mV vs. 1.55 ± 0.88 mV; p < 0.01). Conclusions: Ventricular tachycardia originating within the PA has different electrocardiographic and electrophysiologic characteristics from that originating from the RV-end-OT. When mapping the RVOT area, the catheter may be located within the PA if a low-voltage atrial or local ventricular potential of <1-mV amplitude is recorded. Heightened attention must be paid if RFCA is required within the PA. [Copyright &y& Elsevier]