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Abstract Background Zero‐fluoroscopic pulsed field ablation (PFA) is the next step in advancing pulmonary vein isolation (PVI) for atrial fibrillation (AF). Methods A workflow incorporating a variable‐loop circular PFA catheter, intracardiac echocardiography (ICE), and a visualized sheath was applied to 15 paroxysmal AF patients. Results It consisted of three steps: (1) positioning a non‐magnetic mapping catheter in the coronary sinus after creating a right atrial matrix, (2) transseptal puncture with the sheath advancement to the left atrium under ICE guidance, and (3) PFA confirming catheter‐tissue contact with tissue proximity indication. Conclusions This zero‐fluoro PFA workflow is feasible without advanced technique.

Abstract Background Atrioventricular nodal reentrant tachycardia (AVNRT) sometimes recurs even after anatomical slow pathway (SP) ablation targeting the rightward inferior extension (RIE). This multicenter study aimed to determine the reasons for AVNRT recurrence. Methods and Results Forty‐six patients were treated successfully for recurrent AVNRT. Initial treatment was for 38 slow‐fast AVNRTs, 3 fast‐slow AVNRTs, 2 slow‐slow AVNRTs, 2 slow‐fast and fast‐slow AVNRTs, and 1 noninducible AVNRT. All initial treatments were of RF application to the RIE; SP elimination was achieved in 11, dual AVN physiology was seen in 29, and AVNRT remained inducible in 5. The recurrent AVNRTs included 34 slow‐fast AVNRTs, 6 fast‐slow AVNRTs, 3 slow‐slow AVNRTs, 2 slow‐fast and fast‐slow AVNRTs, and 1 slow‐fast and slow‐slow AVNRTs. Successful ablation site was within the RIE in 39 and left inferior extension in 7. In 30 of 39, the successful RIE site was in the same area or higher than that of the initial procedure. Conclusion For a high majority (around 85%) of patients in whom AVNRT recurs after initial ablation success, the site of a second successful procedure will be within the RIE even though the RIE was originally targeted. Furthermore, a high majority (around 86%) of sites of successful ablation will be higher than those originally targeted.

Abstract Background Although pulmonary vein isolation (PVI) for atrial fibrillation (AF) utilizing radiofrequency (RF) applications with a very high‐power and short‐duration (vHPSD) has shortened the procedure time, the determinants of pulmonary vein (PV) gaps in the first‐pass PVI and acute PV reconnections are unclear. Methods An extensive encircling PVI was performed with the QDOT MICRO catheter with a vHPSD (90 W–4 s) in 30 patients with AF (19 men, 64 ± 10 years). The association of the PV gap sites (first‐pass PVI failure, acute PV reconnections [spontaneous reconnections or dormant conduction provoked by adenosine triphosphate] or both) with the left atrial (LA) wall thickness and LA bipolar voltage on the PVI line and ablation‐related parameters were assessed. Results PV gaps were observed in 29 (6%) of 480 segments (16 segments per patient) in 17 patients (56%). The PV gaps were associated with the LA wall thickness, bipolar voltage, and the number of RF points (LA wall thickness, 2.5 ± 0.5 vs. 1.9 ± 0.4 mm, p

Abstract Background This study aimed to establish a systematic method for diagnosing atrioventricular nodal reentrant tachycardia (AVNRT) with a bystander concealed nodoventricular pathway (cNVP). Methods We analyzed 13 cases of AVNRT with a bystander cNVP, 11 connected to the slow pathway (cNVP‐SP) and two to the fast pathway (cNVP‐FP), along with two cases of cNVP‐related orthodromic reciprocating tachycardia (ORT). Results The diagnostic process was summarized in three steps. Step 1 was identification of the presence of an accessory pathway by resetting the tachycardia with delay (n = 9) and termination without atrial capture (n = 4) immediately after delivery of a His‐refractory premature ventricular contraction (PVC). Step 2 was exclusion of ORT by atrio‐His block during the tachycardia (n = 4), disappearance of the reset phenomenon after the early PVC (n = 7), or dissociation of His from the tachycardia during ventricular overdrive pacing (n = 1). Moreover, tachycardia reset/termination without the atrial capture (n = 2/2) 1 cycle after the His‐refractory PVC was specifically diagnostic. Exceptionally, the disappearance of the reset phenomenon was also observed in the two cNVP‐ORTs. Step 3 was verification of the AVN as the cNVP insertion site, evidenced by an atrial reset/block preceding the His reset/block in fast–slow AVNRT with a cNVP‐SP and slow–fast AVNRT with a cNVP‐FP or His reset preceding the atrial reset in slow–fast AVNRT with a cNVP‐SP. Conclusion AVNRT with a bystander cNVP can be diagnosed in the three steps with few exceptions. Notably, tachycardia reset/termination without atrial capture one cycle after delivery of a His‐refractory PVC is specifically diagnostic.

Abstract Background The effects of the patient's disease awareness on the management of postablation of atrial fibrillation (AF) are unknown. Methods One hundred thirty‐three AF patients undergoing an initial ablation were given a disease awareness questionnaire with a score of 16 points (8 points about AF in general and 8 points about oral anticoagulants) for the Jessa Atrial Fibrillation Knowledge Questionnaire (JAKQ) before and 1‐year‐after ablation. We divided them into the poor disease awareness group and good disease awareness group according to the median value (75%) of the total JAKQ score about AF in general, and compared the baseline patient characteristics and the 1‐year changes in the JAKQ score, medication adherence, blood pressure, laboratory data, echocardiographic parameters, and AF/atrial tachycardia (AT) recurrence rate between the two groups. Results Forty‐two (31.6%) patients were classified as having poor disease awareness (

Abstract Background Ablation strategies and modalities for atrial fibrillation (AF) have transitioned over the past decade, but their impact on post‐ablation medication and clinical outcomes remains to be fully investigated. Methods We divided 682 patients who had undergone AF ablation in 2014–2019 (420 paroxysmal AFs [PAF], 262 persistent AFs [PerAF]) into three groups according to the period, that is, the 2014–2015 (n = 139), 2016–2017 (n = 244), and 2018–2019 groups (n = 299), respectively. Results Persistent AF became more prevalent and the left atrial (LA) diameter larger over the 6 years. Extra‐pulmonary vein (PV)‐LA ablation was more frequently performed in the 2014–2015 group than in the 2016–2017 and 2018–2019 groups (41.1% vs. 9.1% and 8.1%; p

Abstract Background A subeustachian pouch (SEP) often hinders the completion of a cavotricuspid isthmus (CTI) ablation of typical atrial flutter (AFL) and sometimes causes steam‐pops during a power‐controlled ablation. We hypothesized that real‐time bull's‐eye monitoring of the catheter surface temperature might be useful to locate the SEP where the temperature can rise rapidly, and a temperature‐controlled ablation might avoid steam pops. This study aimed to demonstrate this hypothesis. Methods A temperature‐controlled CTI ablation with a QDOT MICRO™ catheter (n = 10) and a conventional power‐controlled CTI ablation (n = 10) were performed with an output power of 35 W. During the RF application, the bull's eye monitor for monitoring the catheter surface temperatures was assessed. A “red‐bull sign” was defined as an entire red‐colored bull's‐eye monitor, indicating that the catheter‐tip temperature of all 6 thermocouples rose rapidly over 47°C. Results In a total of 115 lesions (12 ± 3 per patient), a “red‐bull sign” was observed in 39 (33.9%) lesions where the RF output was reduced to 26 ± 8 W. All 39 “red‐bull sign” lesions corresponded to the location of the SEP as delineated by ICE before the ablation. The red‐bull sign accurately indicated the presence of a SEP with a sensitivity of 84.7% and specificity of 100%. Bidirectional block of the CTI was completed in all patients in either catheter group without any steam‐pops. Conclusion Real‐time surface temperature monitoring and a red‐bull sign might be useful to detect the SEP. A temperature‐controlled CTI ablation with the QDOT MICRO catheter might be safe for avoiding steam pops.

Background: Although pulmonary vein isolation (PVI) for atrial fibrillation (AF) utilizing radiofrequency (RF) applications with a very high-power and short-duration (vHPSD) has shortened the procedure time, the determinants of pulmonary vein (PV) gaps in the first-pass PVI and acute PV reconnections are unclear. Methods: An extensive encircling PVI was performed with the QDOT MICRO catheter with a vHPSD (90 W-4 s) in 30 patients with AF (19 men, 64 ± 10 years). The association of the PV gap sites (first-pass PVI failure, acute PV reconnections [spontaneous reconnections or dormant conduction provoked by adenosine triphosphate] or both) with the left atrial (LA) wall thickness and LA bipolar voltage on the PVI line and ablation-related parameters were assessed. Results: PV gaps were observed in 29 (6%) of 480 segments (16 segments per patient) in 17 patients (56%). The PV gaps were associated with the LA wall thickness, bipolar voltage, and the number of RF points (LA wall thickness, 2.5 ± 0.5 vs. 1.9 ± 0.4 mm, p < .001; bipolar voltage, 2.59 ± 1.62 vs. 1.34 ± 1.14 mV, p < .001; RF points, 6 ± 2 vs. 4 ± 2, p = .008) but were not with the other ablation-related parameters. Receiver operating characteristic curves yielded that an LA wall thickness ≥2.3 mm and bipolar voltage ≥2.40 mV were determinants of PV gaps with an area under the curve of 0.82 and 0.73, respectively. Conclusions: The LA voltage and wall thickness on the PV-encircling ablation line were highly associated with PV gaps using the 90 W/4 s-vHPSD ablation. [ABSTRACT FROM AUTHOR]