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Aims Catheter ablation (CA) of idiopathic ventricular arrhythmias (VAs) from the epicardial left ventricular summit is challenging. The endocardial approach targets two sites: the endocardial closest site (ECS) to the epicardial earliest activation site (epi-EAS) and the endocardial earliest activation site (endo-EAS). We aimed to differentiate between cases where CA at the ECS was effective and where CA at the endo-EAS yielded success. Methods and results Fifty-eight patients (47 men; age 60 ± 13 years) were analysed with VAs in which the EAS was observed in the coronary venous system (CVS). Overall, VAs were successfully eliminated in 42 (72%) patients: 8 in the CVS, 8 where the ECS matched with the endo-EAS, 11 at the ECS, and 15 at the endo-EAS. A successful ECS ablation was associated with a shorter epi-EAS–ECS distance (10.2 ± 4.7 vs. 18.8 ± 5.3 mm; P < 0.001) and shorter epi-EAS–left main coronary trunk (LMT) ostial distance (20.3 ± 7.6 vs. 30.3 ± 8.4 mm; P = 0.005), with optimal cut-off values of ≤12.6 and ≤24.0 mm, respectively. A successful endo-EAS ablation was associated with an earlier electrogram at the endo-EAS [23 (8, 36) vs. 15 (0, 19) ms preceding the QRS; P < 0.001] and shorter epi-EAS–endo-EAS interval [6 (1, 8) vs. 22 (12, 25) ms; P < 0.001], with optimal cut-off values of ≥18 and ≤9 ms, respectively. Conclusion Shorter anatomical distances between the epi-EAS and ECS, and between the epi-EAS and LMT ostium, predict a successful ECS ablation. The prematurity of the endo-EAS electrogram and a shorter interval between the epi-EAS and endo-EAS predicted a successful endo-EAS ablation. [ABSTRACT FROM AUTHOR]

Introduction: In patients with prior atrial septal defect (ASD) closure and atrial tachyarrhythmias, transseptal puncture can be challenging. Methods and Results: This case report discusses a 65‐year‐old man who had previously undergone pulmonary vein isolation (PVI) and cavo‐tricuspid isthmus ablation for atrial fibrillation before ASD closure, respectively. He developed atrial tachycardia (AT) and underwent catheter ablation. AT was diagnosed as peri‐mitral flutter and the mitral isthmus (MI) linear ablation via a trans‐aortic approach successfully terminated it. Conclusion: This case demonstrates the feasibility and safety of transaortic MI linear ablation in patients with ASD closure devices or anatomical challenges when transseptal puncture is difficult. [ABSTRACT FROM AUTHOR]

Background Bow Hunter's syndrome is vertebral basilar artery insufficiency caused by mechanical occlusion of the vertebral artery during head rotation. This is often due to the formation of osteophytes, herniated discs, cervical spondylosis, or tumours. However, whether the contralateral vessel is organically stenotic is not well known. Case summary A 79-year-old man was referred to our department for a close examination of syncope because the transient loss of consciousness occurring when he was made to turn his head to the left was reproducibly induced and recovered when his face was returned to the normal position. The carotid massage did not induce significant bradycardia or hypotension bilaterally, and Holter electrocardiography, echocardiography, head-up tilt test, coronary angiography, and an acetylcholine stress test showed no obvious abnormalities. A 3D CT angiography was performed to investigate the possibility of vertebrobasilar artery insufficiency, as C3/4 cervical spondylosis, and the left vertebral artery was compressed by the C4 superior process osteophyte, indicating hypoplasia of the contralateral vertebral artery. Vertebral artery angiography and intravascular ultrasound (IVUS) showed moderate stenosis of the left vertebral artery, and IVUS showed a half-circumferential calcified lesion. Compared to the midline position, the stenosis worsened at the site of compression and drainage when the patient turned left downward, and a diagnosis of Bow Hunter's syndrome was made. Discussion Bow Hunter's syndrome is characterized by vertebrobasilar insufficiency. Intravascular ultrasound clearly showed that the lesion was not only stenotic due to compression but also had plaque growth due to continuous mechanical stimulation. [ABSTRACT FROM AUTHOR]

Background The radiofrequency catheter ablation of peri-mitral atrial flutter is occasionally difficult, mostly due to epicardial or intramural conduction on the mitral isthmus (MI). However, cryoballoon ablation (CBA) of peri-mitral atrial flutter refractory to radiofrequency ablation has not been reported. Case summary We report a case of a 66-year-old male patient who experienced a recurrence of atypical atrial flutter and underwent the sixth catheter ablation. The activation and entrainment maps showed that this atypical atrial flutter (AFL) was peri-mitral AFL via pathways other than endocardial conduction in the MI. Previous radiofrequency catheter ablation attempts on the MI line, including endocardial, coronary sinus, and epicardial ablations, failed to achieve a bidirectional block of the MI. In this case, we selected CBA for the MI area and successfully achieved a bidirectional block of the MI. Discussion Although using CBA in the MI is off-label, it could be safely implemented using CARTOUNIVU™. We attributed the success of the bidirectional block of the MI in this case to the crimping of the northern hemisphere of the CBA to the mitral isthmus area, which resulted in the formation of a broad, uniform, and deep ablation lesion site. [ABSTRACT FROM AUTHOR]

T‐wave oversensing in pacemakers is rare because the set sensitivity is generally fixed. However, several models of pacemaker employ automatic sensitivity adjustment. Here, we present two cases of atrioventricular block treated by implantation of the pacemaker with automatic sensitivity adjustment. After implanting the pacemaker with automatic sensitivity adjustment, ventricular pacing suppression due to T‐wave oversensing occurred. In both cases, T‐wave oversensing disappeared after adjusting the setting sensitivity from 0.9 to 2.0 mV. [ABSTRACT FROM AUTHOR]

Introduction: Posterior wall isolation (PWI) combined with pulmonary vein isolation (PVI) has proven effective for persistent atrial fibrillation (AF). However, when performing PWI, creating transmural lesions with subendocardial ablation is sometimes difficult. Endocardial unipolar voltage amplitude had a higher sensitivity than bipolar voltage mapping for identifying intramural viable myocardium in the atria. In this study, we aimed to retrospectively investigate the correlation between the residual potential in the posterior wall (PW) following PWI for persistent AF and atrial arrhythmia recurrence using endocardial unipolar voltage. Methods: This was a single‐center observational study. Patients who underwent PVI and PWI for persistent AF in the first procedure between March 2018 and December 2021 at the Tokyo Metropolitan Hiroo Hospital were included in this study. The patients were divided into two groups based on the presence of residual unipolar PW potentials after PWI with a cutoff of 1.08 mV and the recurrence of atrial arrhythmias was compared. Results: In total, 109 patients were included in the analysis. Forty‐three patients had residual unipolar potentials after PWI and 66 patients had no residual unipolar potentials. The atrial arrhythmia recurrence rate was significantly higher in the group with residual unipolar potential (41.8% vs. 17.9%, p = 0.003). The residual unipolar potential was an independent predictor of recurrence (odds ratio: 4.53; confidence interval: 1.67–12.3, p = 0.003). Conclusion: Residual unipolar potential after PWI for persistent AF is associated with recurrent atrial arrhythmias. [ABSTRACT FROM AUTHOR]

Background The pulmonary vein (PV) variant is present in 23–38% of patients who undergo atrial fibrillation ablation, and the common inferior PV (CIPV) variant is a rare PV variant that has been reported in 0.9–1.5% of patients. The arrhythmogenicity of the common trunk of the CIPV is unknown. Case summary A 77-year-old woman underwent catheter ablation for paroxysmal atrial fibrillation (AF). Preoperative computed tomography revealed a common trunk from which the bilateral inferior PVs and a left superior PV originated. The voltage map of the left atrium (LA) showed three PVs stemming from a common trunk. There was a low-voltage area bounded by the common trunk entrance. An isolation line was created to connect the right superior PV and the common trunk. Twelve months later, AF recurred. The voltage map in second session showed residual irregular potentials at the boundary between the common trunk and the LA, and posterior wall isolation was performed. Postoperatively, the patient maintained sinus rhythm with no antiarrhythmic drugs during the 12-month follow-up period. Discussion The CIPV is likely to predict the AF recurrence, even if preoperative voltage mapping shows a low voltage area. Substrate modification should be performed on abnormal potentials at the entrance of the common trunk, even though no potential is detected in the PVs or their antrum. [ABSTRACT FROM AUTHOR]

Introduction: Local impedance (LI) parameters of IntellaNav STABLEPOINT for successful pulmonary vein isolation (PVI) of atrial fibrillation (AF) remain unclear. The purpose of this study was to seek LI data achieving successful PVI. Methods: Consecutive AF patients who underwent catheter ablation with STABLEPOINT were prospectively enrolled in two centers. PVI was performed under a constant 35‐or 40‐watt power, 20‐s duration, and >5‐g contact force. The operators were blinded to the LI data. The characteristics of all ablation points with/without conduction gaps (Unsuccess or Success tags) after the first‐attempt PVI were evaluated for the right/left PVs and anterior/posterior wall (RPV/LPV and AW/PW, respectively), and cutoff values of LI data were calculated for successful lesion formation. Results: A total of 5257 ablation points in 102 patients (65 [58–72] years old, 65.7% male) were evaluated. The LI drop values were higher in the Success tags than Unsuccess tags on the LPV‐AW and RPV‐AW/PW (p <.001), except for the LPV‐PW (p =.105). The %LI drop values (LI drop/initial LI) were higher for the Success tags in all areas (15.8 [12.2%–19.6%] vs. 11.6 [9.7%–15.6%] in LPV‐AW: p <.001, 15.0 [11.5%–19.3%] vs. 11.4 [8.7%–17.3%] in LPV‐PW: p =.035, 15.3 [11.5%–19.4%] vs. 9.9 [8.1%–13.7%] in RPV‐AW: p <.001, and 13.3 [10.1%–17.4%] vs. 8.1 [6.3%–9.5%] in RPV‐PW, p <.001). The LI drop and %LI drop cutoff values were 20.0 ohms and 11.6%, respectively. Conclusions: An insufficient LI drop with STABLEPOINT was associated with a gap formation during PVI, and the best cutoff values for the LI drop and %LI drop were 20.0 ohms and 11.6%, respectively. [ABSTRACT FROM AUTHOR]