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.

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.

Bidirectional rotating biatrial tachycardia.

A 72-year-old man was treated for recurrent atrial tachycardia (AT) and underwent ablation. The AT was diagnosed as bi-AT based on the activation map and the postpacing interval. Another AT appeared and was diagnosed as bi-AT by the same method. Surprisingly, the circuits of both ATs were perfectly matched and rotated in opposite directions. The left atrial anteroseptal wall was ablated during the AT. The AT was immediately stopped and was no longer induced.

Left atrial macroreentrant tachycardia via Bachmann bundle revealed by epicardial mapping.

Although it is common for bi-atrial tachycardia (AT) circuits to include the Bachmann bundle, there are few reports of its role in left AT circuits. A 77-year-old man was admitted for recurrent AT with a cycle length of 425 ms. The endocardial and epicardial activation map revealed an AT circuit located in the left atrial anterior wall and transverse pericardial sinus, showing a centrifugal pattern stemming from the left atrial appendage. After radiofrequency ablation, AT was no longer induced. This case suggests that the Bachmann bundle may be part of the left AT circuit.

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.

Recurrent ischemic stroke in patients with atrial fibrillation ablation and prior stroke: A study based on etiological classification.

BACKGROUND: Different subtypes of ischemic stroke may have different risk factors, clinical features, and prognoses. This study investigated the incidence and mode of stroke recurrence in patients with a history of stroke who underwent atrial fibrillation (AF) ablation. METHODS: Of 825 patients who underwent AF ablation from 2006 to 2016, 77 patients (9.3%, median age 69 years) with a prior ischemic stroke were identified. Patients were classified as those with prior cardioembolic (CE) stroke (n = 55) and those with prior non-CE stroke (n = 22). The incidence and pattern of stroke recurrence were investigated. RESULTS: The incidence of asymptomatic AF (54.5% vs 22.7%; P = .011) and left atrial volume (135.8 mL vs 109.3 mL; P = .024) was greater in the CE group than in the non-CE group. Anticoagulation treatment was discontinued at an average of 28.1 months following the initial ablation in 34 (44.2%) patients. None of the patients developed CE stroke during a median 4.1-year follow-up. In the non-CE group, 2 patients experienced recurrent non-CE stroke (lacunar infarction in 1 and atherosclerotic stroke in 1); however, AF was not observed at the onset of recurrent ischemic stroke. CONCLUSIONS: In patients with a history of stroke who underwent catheter ablation for AF, the incidence of recurrent stroke was 0.54/100 patient-years. The previous stroke in these patients may not have been due to AF in some cases; therefore, a large-scale prospective study is warranted to identify the appro priate antithrombotic therapy for the prevention of potentially recurrent stroke.