Efficacy and safety of atrial fibrillation ablation in heart failure patients with left ventricular ejection fraction less than 50.

INTRODUCTION: The efficacy of catheter ablation in patients with low cardiac function has been previously reported; however, only a few studies have included mid-range ejection fraction (mrEF). This study aimed to evaluate the efficacy and safety of atrial fibrillation (AF) ablation in patients with left ventricular ejection fraction (LVEF) < 50%. METHODS: This study retrospectively analyzed 79 patients (reduced ejection fraction [rEF]/mrEF, 38/41; paroxysmal/persistent, 37/42; heart failure hospitalizations within one year before ablation, 36 [45.6%]) who underwent the first ablation procedure at our hospital from April 2017 to December 2021. Radiofrequency ablation and cryoablation were performed for 69 and 10 patients, respectively. RESULTS: Complications included pacemaker implantation for postoperative sick sinus syndrome in one patient and inguinal hematoma in one patient. Regarding efficacy, there were significant postoperative improvements in echocardiographic data, blood test values, and diuretic use. After a mean follow-up of 60 months, 86.1% patients had no AF recurrence. There were 9 heart failure hospitalizations (11.4%) and 5 all-cause deaths (6.3%); no significant differences were found between the rEF and mrEF groups. No significant predictors of AF recurrence were found in preoperative patient characteristics. CONCLUSION: AF ablation in patients with LVEF <50% significantly improved cardiac and renal functions with few complications, resulting in a high non-recurrence rate and reduced heart failure.

Efficacy of isoproterenol in the evaluation of dormant conduction and arrhythmogenic foci identification in atrial fibrillation ablation.

BACKGROUND: Catheter ablation for atrial fibrillation (AF) is an established therapy. However, postoperative recurrence is a serious issue caused by the reconduction of the isolated pulmonary veins (PV) and the onset of non-PV foci. The objectives of this study were to elucidate dormant conduction, confirm PV arrhythmia substrate, induce non-PV foci after PV isolation, and assess the acute efficacy of high dose isoproterenol (ISP) when administered in addition to adenosine. METHODS: The study consisted of 100 patients with drug-refractory AF (paroxysmal and persistent) who underwent ablation therapy (either radio-frequency or cryoballoon ablation) as the first-line of therapy at our hospital. All patients first underwent PV isolation (PVI) and were administered adenosine followed by ISP (6 µg × 5 min). The effects were observed, and the therapeutic strategy was evaluated. RESULTS: Persistent dormant conduction due to ISP administration was observed in 13 patients. In over half of the patients, arrhythmia substrates were identified in the PV. Ten patients presented with persistent PV firing. The ablation of non-PV foci was additionally performed in 23 patients. CONCLUSIONS: We found that dormant conduction, as a result of ISP administration, is persistent and ISP is useful when performing an ablation. In addition, ISP administration is useful for the identification of PV arrhythmia substrates and induction of non-PV foci. However, the effectiveness of ISP may be partially due to the complementary effect of adenosine, and, therefore, a combination of the two drugs seems preferable.

Distribution of Anti-Factor Xa Activity in Patients on Edoxaban Therapy for Non-Valvular Atrial Fibrillation.

BACKGROUND: The distribution of anti-factor Xa activity (AXA) values in non-valvular atrial fibrillation (NVAF) patients on edoxaban therapy has not been fully elucidated. METHODS AND RESULTS: The steady-state trough and peak AXA values were measured in 66 NVAF patients. The trough AXA value did not differ significantly between the 60-mg and the 30-mg OD groups (0.17±0.13 IU/ml vs. 0.12±0.11 IU/ml, respectively; P=0.17). Similarly, the peak AXA value did not differ significantly between the 2 groups (1.45±0.81 IU/ml vs. 1.25±0.48 IU/ml, respectively; P=0.26). CONCLUSIONS: Recommended dosing should be followed for sufficient efficacy of edoxaban. (Circ J 2016; 80: 745-747).

Measurement of Anti-Factor Xa Activity in Patients on Apixaban for Non-Valvular Atrial Fibrillation.

BACKGROUND: Chromogenic anti-factor Xa activity (AXA) assay is reported to be the most appropriate method to measure the pharmacodynamics of apixaban, but the distribution of AXA in non-valvular atrial fibrillation (NVAF) patients on apixaban therapy has not been fully elucidated. METHODS AND RESULTS: Steady-state trough and peak AXA were measured in 124 NVAF patients taking apixaban. In 25 patients, baseline, first peak, and trough AXA were also examined, and were 0.01±0.02 IU/ml, 0.83±0.43 IU/ml, and 0.34±0.17 IU/ml, respectively. First trough AXA was significantly lower than steady-state trough AXA, although it was significantly higher than baseline (P<0.0001). Similarly, first peak AXA was significantly lower than steady-state peak AXA (P<0.0001). In 124 patients, steady-state peak AXA was significantly higher in the 5-mg b.i.d. group than in the 2.5-mg b.i.d. group (2.05±0.73 IU/ml vs. 1.51±0.65 IU/ml, respectively; P<0.001), although there was no significant difference in trough AXA. Other than dose, age and serum creatinine were significantly related to both trough and peak AXA. CONCLUSIONS: The distribution of AXA in Japanese NVAF patients on apixaban therapy in daily clinical practice both in the acute and steady-state phase was measured. In patients taking apixaban, measurement of AXA clearly showed the pharmacodynamic profile of this drug.

Evaluation of arrhythmogenic foci using a novel automated detection algorithm and isoproterenol in persistent atrial fibrillation.

PURPOSE: The CARTOFINDER mapping system analyzes activation patterns using unipolar potentials during atrial fibrillation (AF), where isoproterenol (ISP) is conventionally used to induce non-pulmonary vein (PV) foci and confirm PV arrhythmogenicity. In 20 patients with persistent AF who underwent ablation at our hospital, arrhythmogenic foci were evaluated using both these methods. METHODS: Before pulmonary vein isolation (PVI), PV and left atrium (LA) were analyzed during AF using CARTOFINDER, and the isolation line was determined based on the results. After PVI, ISP was loaded after return of sinus rhythm and confirmation of the presence of arrhythmogenic foci. The activation site in LA was ablated at the discretion of the surgeon. RESULTS: Focal activation sites detected by CARTOFINDER correlated with the arrhythmogenic foci induced by ISP in the PVs. The results also showed that a greater number of focal activation sites in the PVs correlated to an increased response to ISP administration. In one patient, it was observed that the focal activation site identified in the PV also coincided with the site of the origin of automaticity induced by ISP after PVI. CONCLUSION: CARTOFINDER and ISP both reliably determined the presence of arrhythmogenic foci in PV, in patients with persistent AF. Knowledge of the nature of arrhythmogenic foci in non-PV is considered to be a topic for future studies, and further data collection is required.

Contrast-enhanced computed tomography for optimizing the outcomes of pulmonary vein isolation with cryoablation -the role of isolation of PVs including carina.

PURPOSE: Compared with conventional pulmonary vein isolation (PVI) with radiofrequency ablation, PVI with cryoballoon is an easier and shorter procedure without reconnection, particularly in the superior pulmonary vein. However, the durability of the cryoballoon may be reduced due to anatomical factors and the position of the pulmonary vein (PV). Further, inadequate isolation of the carina leads to recurrence of atrial fibrillation (AF). We aimed to determine whether using contrast-enhanced computed tomography (CT) for patient selection improves the early success rate and prevents the recurrence of AF in PVI with cryoballoon. METHODS: We evaluated patients who underwent ablation for paroxysmal atrial fibrillation in our hospital between July 2019 and November 2020. After excluding patients with contraindications for cryoablation, 50 patients were selected through visual inspection of the results of preoperative contrast-enhanced CT. A treatment plan was established, and the clinical course and outcomes were followed up. RESULTS: Of the 200 PVs of the 50 patients, only 8 PVs (4%) were incompletely isolated with a single cryoablation. Six of the eight PVs were successfully isolated with additional cryoablation. Only 2 patients (4%) underwent additional PVI with radiofrequency ablation. Four patients had AF recurrence within a mean follow-up period of 14.3 ± 5.1 months. The rate of sinus rhythm maintenance was 92%. PV reconnection was observed in 2 patients. None of the patients had postoperative atrial flutter. CONCLUSIONS: Selecting patients for cryoablation according to contrast-enhanced CT findings made the procedure easier to perform, leading to improved early success rates and clinical course.

Isolated bilateral external iliac artery dissections with emotional stress.

We present a patient with isolated bilateral external iliac artery dissections associated with emotional stress. The diagnosis should be kept in mind in young, fit patients presenting lower back pain occurring subsequent to emotional stress.

A case of accessory pathway mapped with ultra-high-resolution mapping led to a coronary sinus diverticulum.

Ultra-high-resolution mapping is useful in the ablation of accessory pathways. However, in patients with accessory pathways in the coronary sinus (CS) diverticulum, treatment with endocardial ablation may be challenging. Patients suspected of having subepicardial accessory pathways may require the examination of the venous anomaly using CS angiography.

Secondary Cardiac Lymphoma Presenting as Sick Sinus Syndrome and Atrial Fibrillation Which Required Leadless Pacemaker Implantation.

Cardiac involvement of malignant lymphoma is relatively common, although such a phenomenon has subclinical manifestations that are difficult to detect. We herein describe a patient with atrial fibrillation and sick sinus syndrome as the main symptoms. Computed tomography showed a mass in the right atrium extending into the superior vena cava (SVC). We implanted the patient with a leadless pacemaker. Transvenous biopsy revealed a diffuse large B-cell lymphoma. The patient was treated successfully with chemotherapy including rituximab. This case suggested that cardiac lymphoma may cause sick sinus syndrome, and leadless pacemaker implantation is a safe treatment option in patients with partial SVC obstruction.

The appearance of a single left atrial tachycardia as two different types on preoperative surface and intracardiac ECG of pacemaker due to progressive cardiac conduction disturbance.

We treated a patient with PCCD whose single left AT appeared as two different types on preoperative surface and intracardiac ECG from a pacemaker. The diagnosis was hindered by the fact that the conduction block encompassed interatrial block and the pacemaker A-wave was captured at the right atrial appendage.