Peak Frequency Annotation Algorithm Guided Slow Pathway Ablation in Typical Atrioventricular Nodal Re-entrant Tachycardia.

BACKGROUND: The slow-pathway potential is difficult to annotate because it is buried within the atrial potential. Omnipolar technology Near Field (OTNF) in Ensite X can automatically annotate the peak frequency potential associated with acquired intracardiac electrograms. OBJECTIVE: This study aimed to visualize the junction between the transitional cells and the slow pathway using a peak frequency map with OTNF and evaluate whether the high-frequency site around the tricuspid annulus (TA) is an effective target for slow pathway ablation. METHODS: This prospective observational study enrolled 37 patients with typical atrioventricular nodal re-entrant tachycardia. Patients underwent slow pathway ablation using peak frequency map (n = 17) and the conventional approach based on anatomical and electrophysiological findings (n = 20). RESULTS: High-frequency sites were distributed at the TA side of 4-5 o'clock in all peak frequency map-guided patients. The distance to His bundle from successful ablation site was farther (24.0 ± 4.8 vs. 12.7 ± 4.0 mm, p < 0.0001), junctional rhythm was slower (88 ± 17 vs. 115 ± 12 bpm, p < 0.0001), time to junctional rhythm after radiofrequency application was shorter (3.4 ± 1.4 vs. 8.2 ± 4.6 sec, p < 0.0001), and elimination rate of jump up (71 vs. 30%, p = 0.02) was higher in the peak frequency map-guided group. CONCLUSION: The high-frequency site of the TA at 4-5 o'clock in the peak frequency map could be a novel target of slow pathway ablation with high safety, efficiency, and efficacy.

Raise-up technique for the creation of left atrial roof lesion: A useful technique with cryoballoon for persistent atrial fibrillation.

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.

Cryoballoon ablation of peri-mitral atrial flutter refractory to radiofrequency ablation: a case report.

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.

T-wave oversensing after implantation of pacemakers with automatic sensitivity adjustment in patients with atrioventricular block.

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.

New-onset atrial high-rate episodes between his bundle pacing and conventional right ventricular septum pacing in patients with atrioventricular conduction disturbance.

BACKGROUND: The effect of His bundle pacing (HBP) on the incidence of new-onset atrial fibrillation (AF) after pacemaker implantation (PMI) for atrioventricular conduction disturbance (AVCD) remains unknown. We compared the incidence of new-onset atrial high-rate episode (AHRE) in conventional right ventricular (RV) septum pacing (RVSP) and His bundle pacing (HBP) after PMI for AVCD. METHODS: One hundred and four consecutive patients who underwent dual chamber PMI for AVCD in our hospital were screened. Thirty-five patients with mitral or aortic valve disease, history of open-heart surgery, prior AF, subclinical AF, cumulative ventricular pacing percentage < 90%, and RV lead revision were excluded, and 69 patients were effectively enrolled in this study. The primary endpoint was new-onset AHRE within the follow-up period. New-onset AHRE was defined as an atrial high-rate episode that occurred 3 months after PMI and lasted for > 6 min at an atrial heart rate > 190 bpm. RV leads were placed in the His bundle region and RV septum region in 22 and 47 patients, respectively. The mean follow-up period was 539 ± 218 days. The follow-up period was 2 years after PMI or until the new-onset AHRE occurred. RESULTS: The incidence of new-onset AHRE was lower in the HBP group than in the RVSP group (11% vs. 43%, p = 0.01). Multivariate analysis in the Cox regression hazard model showed that HBP had a significantly lower risk of new-onset AHRE compared with RVSP (HR = 0.21; 95% confidence interval 0.04-0.78, p = 0.02). CONCLUSION: The incidence of new-onset AHRE was significantly less in HBP compared to RVSP during the 2-year follow-up period after pacemaker implantation in AVCD patients with RV pacing dependence.

Trans-aortic mitral isthmus ablation after surgical patch closure for an atrial septal defect.

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.

Modification of the pulmonary vein antrum is associated with recurrence after durable pulmonary vein isolation for paroxysmal atrial fibrillation.

BACKGROUND: Although previous studies have shown the isolated areas after pulmonary vein isolation (PVI) using cryoballoons (CB) (CB-PVI), no studies have investigated the association between the isolated area and recurrence of atrial fibrillation (AF) and atrial tachycardia (AT). This single-center observational study investigated the association between the ablated area and recurrence rate after durable CB-PVI for paroxysmal AF. METHODS: This study included 76 patients with paroxysmal AF who underwent CB-PVI and established durable PVI with a second procedure, regardless of AF/AT recurrence, 6 months after the first procedure. To compare the ablated zones, we quantified the left- and right-sided PV antral isolation areas and non-ablated posterior wall (PW) area. We examined non-ablated areas of the PW and AF/AT recurrence in the chronic phase. RESULTS: In total, 16 of the 76 patients had AF/AT recurrence. The mean follow-up duration was 34 months. The non-ablated PW area (14.0 ± 4.6 cm2 vs. 11.5 ± 3.7 cm2; p = 0.0213) and the ratio of the non-ablated PW area to the whole PW area (NAPW) (52.9 ± 9.1% vs. 44.8 ± 9.8%; p = 0.003) were significantly higher in the AF/AT recurrence group than in the AF/AT non-recurrence group. NAPW > 50% was an independent predictor of AF/AT recurrence. CONCLUSION: The NAPW after durable CB-PVI is associated with AF/AT recurrence. PW isolation or additional applications on the PV antrum with cryoballoon may be considered in addition to PVI in paroxysmal AF, especially in patients with dilated left atria.

Association between residual unipolar voltage and arrhythmia recurrence after left atrial posterior wall isolation for persistent atrial fibrillation.

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.

Comparison of the efficacy of excimer laser coronary angioplasty for ST-segment elevation myocardial infarction with onset-to-balloon time.

Excimer laser coronary angioplasty (ELCA) vaporizes plaques and thrombi, provides better microcirculation, and reduces peripheral embolism when treating acute coronary syndrome. Studies on the efficacy of ELCA for long onset-to-balloon time ST-segment elevation myocardial infarction (STEMI) are limited. Thus, we aimed to examine the efficacy of ELCA for STEMI using the onset-to-balloon time (OBT). A total of 319 patients with STEMI who underwent percutaneous coronary intervention from 2009 to 2012 and from 2015 to 2019 were enrolled. Patients who underwent PCI in 2009-2012 were considered the conventional group, and those treated with ELCA in 2015-2019 were considered the ELCA group. Patients were stratified by OBT. The endpoints were the final thrombolysis in myocardial infarction (TIMI) grade, myocardial blush grade (MBG), and slow-flow or no-reflow phenomenon during the procedure. The ELCA group had 167 patients, and the conventional group had 123. There was no significant difference in achieving final TIMI 3 between the groups. The acquisition rate of final MBG 3 was significantly higher in the ELCA than in the conventional group (79.6% vs. 65.9%; P = 0.01). There was a significant difference between the groups with OBT 12-72 h (82.1% vs. 56.0%; P = 0.031). The slow- or no-reflow incidence during the procedure was significantly lower in the ELCA than in the conventional group with OBT 12-72 h (17.8% vs. 52.2%; P = 0.019). ELCA improves the MBG and reduces intraoperative slow- or no-reflow phenomenon in patients with STEMI, 12-72 h after onset. ELCA will be useful in preventing peripheral embolism in patients with long onset-to-balloon time STEMI.

A case report of paroxysmal atrial fibrillation in three pulmonary veins presenting a common trunk.

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.

Impact of small diameter and low level of emission laser coronary atherectomy in patients with acute myocardial infarction.

Excimer laser coronary atherectomy (ELCA) is an effective treatment to remove intracoronary thrombi. In the present study, we compared in-hospital mortality in patients with acute myocardial infarction (AMI) who underwent conventional treatment and conventional treatment plus ELCA. Among 656 patients who were admitted to our hospital through the Tokyo CCU Network, 104 patients with AMI who were treated by percutaneous coronary intervention between January 2013 and December 2016 met inclusions criteria and underwent conventional treatment with ELCA (ELCA group) and 89 underwent conventional treatment alone (conventional group). We retrospectively evaluated in-hospital mortality within 30 days and used propensity score (PS) matching to reduce assignment bias and multivariate analysis to detect the predictors of in-hospital mortality. In-hospital mortality rate was significantly lower in the ELCA group before and after PS matching (2.9% vs. 13.5%, p = 0.006 before PS matching, and 2.8% vs. 14.1%, p = 0.016 after PS matching). After PS matching, ß-blocker or statins use, incidence of shock, Killip classification, and door-to-balloon time were not significantly different. A multivariate logistic regression analysis identified ELCA, dyslipidemia, shock, and left ventricular ejection fraction as independent predictors of in-hospital mortality (odds ratio (OR), 0.147, 95% confidence interval [CI], 0.022-0.959, p = 0.045; OR, 0.077, 95% CI, 0.007-0.805, p = 0.032; OR, 6.494, 95% CI, 1.228-34.34, p = 0.028; OR, 0.890, 95% CI, 0.828-0.957, p = 0.002, respectively). Our data indicate that ELCA with the small diameter and low level emission may reduce the in-hospital mortality compared to conventional methods in patients with AMI in drug-eluting stent era.

Clinical Effect of Adaptive Servo-Ventilation on Left Atrial Pressure During Catheter Ablation in Sedated Patients With Atrial Fibrillation.

BACKGROUND: Sedation during pulmonary vein isolation (PVI) for atrial fibrillation often provokes a decline in left atrial (LA) pressure (LAP) under atmospheric pressure and increases the risk of systemic air embolisms. This study aimed to investigate the efficacy of adaptive servo-ventilation (ASV) on the LAP in sedated patients.Methods and Results:Fifty-one consecutive patients undergoing cryoballoon PVI were enrolled. All patients underwent sedation using propofol throughout the procedure. After the transseptal puncture and the insertion of a long sheath into the LA, the LAP was measured. Then, the ASV treatment was started, and the LAP was re-measured. The LAP before and after the ASV support was investigated. Before ASV, the LAP during the inspiratory phase was significantly smaller than that during the expiratory phase (4.9±5.4 mmHg vs. 14.0±5.2 mmHg, P<0.01). The lowest LAP was -2.2±5.1 mmHg and was under 0 mmHg in 37 (73%) patients. After the ASV, the LAP during the inspiratory phase significantly increased to 8.9±4.1 mmHg (P<0.01), and lowest LAP increased to 4.7±5.9 mmHg (P<0.01). The negative lowest LAP value became positive in 30/37 (81%) patients. There were no statistical differences regarding obstructive sleep apnea (OSA), obesity, gender, or other comorbidities between patients with and without a negative lowest LAP after ASV support. CONCLUSIONS: ASV is effective for increasing the LAP above 0 mmHg and might prevent air embolisms during PVI.