Interatrial conduction time is associated with left atrial low voltage area and predicts the recurrence after single atrial fibrillation ablation

Abstract Background Interatrial conduction time (IACT) prolongs in fibrotic left atrium. We tested the hypothesis that IACT is related to left atrial low voltage area (LVA) and predicts the recurrence after single atrial fibrillation (AF) ablation. Methods One hundred sixty‐four consecutive AF patients (79 non‐paroxysmal) who underwent initial ablation in our institute were analyzed. IACT and LVA were defined as interval from the onset of P‐wave to the basal left atrial appendage (P‐LAA) activation, and area with bipolar electrogram < 0.5 mV covering over 5% of the total left atrial surface area during sinus rhythm, respectively. Pulmonary vein antrum isolation, non‐PV foci ablation, and atrial tachycardia (AT) ablation were performed without substrate modification. Results LVA was frequently identified in patients with prolonged P‐LAA ≥ 84 ms (n  = 28) compared with patients with P‐LAA < 84 ms (n  = 136). Patients with P‐LAA ≥ 84 ms were older (71 ± 10 vs. 65 ± 10 years, p  = .0061), and had more frequent non‐paroxysmal AF (75% vs. 43%, p  = .0018), larger left atrial diameter (43.5 ± 4.5 vs. 39.3 ± 5.7 mm, p  = .0003), and higher E/e’ ratio (14.4 ± 6.5 vs. 10.5 ± 3.7, p  < .0001) compared with P‐LAA < 84 ms patients. After a mean follow‐up period of 665 ± 153 days, Kaplan–Meier curve analysis showed that AF/AT recurrences was more frequently observed in patients with prolonged P‐LAA (Log‐rank p  = .0001). Additionally, univariate analysis revealed that P‐LAA prolongation (OR = 1.055 per 1 ms, 95% CI: 1.028–1.087, p  < .0001) and the existence of LVA (OR = 5.000, 95% CI: 1.653–14.485 p  = .0053) were predictors of AF/AT recurrences after single AF ablation. Conclusions Our results suggested that prolonged IACT as measured by P‐LAA was associated with LVA and predicts AT/AF recurrence after single AF ablation

Multiple accessory pathways coexisting with a persistent left superior vena cava: a case report

Abstract Background Wolff–Parkinson–White syndrome is characterized by a short PR interval (delta-wave), long QRS complex, and the appearance of paroxysmal supraventricular tachycardia. Patients with Wolff–Parkinson–White syndrome usually have one accessory pathway, whereas cases with multiple accessory pathways are rare. Persistent left superior vena cava is a vascular anomaly in which the vein drains into the right atrium through the coronary sinus at the junction of the left internal jugular and subclavian veins due to abnormal development of the left cardinal vein. The simultaneous presence of multiple accessory pathways and persistent left superior vena cava has not been reported before. Case presentation A 56-year-old Japanese man with a 5-year history of palpitations was referred for radiofrequency catheter ablation due to increased frequency of tachycardia episodes in the previous 2 months. Persistent left superior vena cava was confirmed by transthoracic echocardiography and computed tomography. An electrophysiological study revealed that the accessory pathways were located in the left lateral wall, anterolateral wall, and posteroseptal region. They were completely ablated with radiofrequency energy application. Conclusions We reported an extremely rare case of a patient with multiple accessory pathways and persistent left superior vena cava. Our case may suggest a potential embryological relationship between the multiple accessory pathways and persistent left superior vena cava

Activation Mechanism of the <i>Streptomyces</i> Tyrosinase Assisted by the Caddie Protein

Tyrosinase (EC 1.14.18.1), which possesses two copper ions at the active center, catalyzes a rate-limiting reaction of melanogenesis, that is, the conversion of a phenol to the corresponding <i>ortho</i>-quinone. The enzyme from the genus <i>Streptomyces</i> is generated as a complex with a “caddie” protein that assists the transport of two copper ions into the active center. In this complex, the Tyr⁹⁸ residue in the caddie protein was found to be accommodated in the pocket of the active center of tyrosinase, probably in a manner similar to that of l-tyrosine as a genuine substrate of tyrosinase. Under physiological conditions, the addition of the copper ion to the complex releases tyrosinase from the complex, in accordance with the aggregation of the caddie protein. The release of the copper-bound tyrosinase was found to be accelerated by adding reducing agents under aerobic conditions. Mass spectroscopic analysis indicated that the Tyr⁹⁸ residue was converted to a reactive quinone, and resonance Raman spectroscopic analysis indicated that the conversion occurred through the formations of μ-η²:η²-peroxo-dicopper­(II) and Cu­(II)-semiquinone. Electron paramagnetic resonance analysis under anaerobic conditions and Fourier transform infrared spectroscopic analysis using CO as a structural probe under anaerobic conditions indicated that the copper transportation process to the active center is a reversible event in the tyrosinase/caddie complex. Aggregation of the caddie protein, which is triggered by the conversion of the Tyr⁹⁸ residue to dopaquinone, may ensure the generation of fully activated tyrosinase

Predictors of outcome after catheter ablation for atrial fibrillation: Group analysis categorized by age and type of atrial fibrillation

Abstract Background The outcome of catheter ablation could probably differ among patients with atrial fibrillation (AF), depending on age and AF type. We aimed to investigate the difference in predictors of outcome after catheter ablation for AF among the patient categories divided by age and AF type. Methods and Results A total of 396 patients with AF (mean age 65.69 ± 11.05 years, 111 women [28.0%]) who underwent catheter ablation from January 2018 to December 2019 were retrospectively analyzed. We divided the patients into four categories: patients with paroxysmal AF (PAF) or persistent AF (PeAF) who were 75 years or younger (≤75 years) or older than 75 years (>75 years). Kaplan–Meier survival analysis demonstrated that patients with PAF aged ≤75 years had the lowest AF recurrence among the four groups (log‐rank test, p = .0103). In the patients with PAF aged ≤75 years (N = 186, 46.7%), significant factors associated with recurrence were female sex (p = .008) and diabetes (p = .042). In the patients with PeAF aged ≤75 years (N = 142, 35.9%), the only significant factor associated with no recurrence was medication with a renin‐angiotensin system inhibitor (p = .044). In the patients with PAF aged >75 years (N = 53, 14.4%), diabetes was significantly associated with AF recurrence (p = .021). No significant parameters were found in the patients with PeAF aged >75 years (N = 15, 4.1%). Conclusions Our findings indicate that the risk factors for AF recurrence after catheter ablation differed by age and AF type

National trends in the outcomes of subarachnoid haemorrhage and the prognostic influence of stroke centre capability in Japan: retrospective cohort study

Objectives To examine the national, 6-year trends in in-hospital clinical outcomes of patients with subarachnoid haemorrhage (SAH) who underwent clipping or coiling and the prognostic influence of temporal trends in the Comprehensive Stroke Center (CSC) capabilities on patient outcomes in Japan.Design Retrospective study.Setting Six hundred and thirty-one primary care institutions in Japan.Participants Forty-five thousand and eleven patients with SAH who were urgently hospitalised, identified using the J-ASPECT Diagnosis Procedure Combination database.Primary and secondary outcome measures Annual number of patients with SAH who remained untreated, or who received clipping or coiling, in-hospital mortality and poor functional outcomes (modified Rankin Scale: 3–6) at discharge. Each CSC was assessed using a validated scoring system (CSC score: 1–25 points).Results In the overall cohort, in-hospital mortality decreased (year for trend, OR (95% CI): 0.97 (0.96 to 0.99)), while the proportion of poor functional outcomes remained unchanged (1.00 (0.98 to 1.02)). The proportion of patients who underwent clipping gradually decreased from 46.6% to 38.5%, while that of those who received coiling and those left untreated gradually increased from 16.9% to 22.6% and 35.4% to 38%, respectively. In-hospital mortality of coiled (0.94 (0.89 to 0.98)) and untreated (0.93 (0.90 to 0.96)) patients decreased, whereas that of clipped patients remained stable. CSC score improvement was associated with increased use of coiling (per 1-point increase, 1.14 (1.08 to 1.20)) but not with short-term patient outcomes regardless of treatment modality.Conclusions The 6-year trends indicated lower in-hospital mortality for patients with SAH (attributable to better outcomes), increased use of coiling and multidisciplinary care for untreated patients. Further increasing CSC capabilities may improve overall outcomes, mainly by increasing the use of coiling. Additional studies are necessary to determine the effect of confounders such as aneurysm complexity on outcomes of clipped patients in the modern endovascular era