Real-world data of radiofrequency catheter ablation in paroxysmal atrial fibrillation: Short- and long-term clinical outcomes from the prospective multicenter REAL-AF Registry.

BACKGROUND: The safety and long-term efficacy of radiofrequency (RF) catheter ablation (CA) of paroxysmal atrial fibrillation (PAF) has been well established. Contemporary techniques to optimize ablation delivery, reduce fluoroscopy use, and improve clinical outcomes have been developed. OBJECTIVE: The purpose of this study was to assess the contemporary real-world practice approach and long-term outcomes of RF CA for PAF through a prospective multicenter registry. METHODS: Using the REAL-AF (Real-world Experience of Catheter Ablation for the Treatment of Symptomatic Paroxysmal and Persistent Atrial Fibrillation; ClincalTrials.gov Identifier: NCT04088071) Registry, patients undergoing RF CA to treat PAF across 42 high-volume institutions and 79 experienced operators were evaluated. The procedures were performed using zero or reduced fluoroscopy, contact force sensing catheters, wide area circumferential ablation, and ablation index as a guide with a target of 380-420 for posterior and 500-550 for anterior lesions. The primary efficacy outcome was freedom from all-atrial arrhythmia recurrence at 12 months. RESULTS: A total of 2470 patients undergoing CA from January 2018 to December 2022 were included. Mean age was 65.2 ±11.14 years, and 44% were female. Most procedures were performed without fluoroscopy (71.5%), with average procedural and total RF times of 95.4 ± 41.7 minutes and 22.1±11.8 minutes, respectively. At 1-year follow-up, freedom from all-atrial arrhythmias was 81.6% with 89.7% of these patients off antiarrhythmic drugs. No significant difference was identified comparing pulmonary vein isolation vs pulmonary vein isolation + ablation approaches. The complication rate was 1.9%. CONCLUSION: Refinement of RF CA to treat PAF using contemporary tools, standardized protocols, and electrophysiology laboratory workflows resulted in excellent short- and long-term clinical outcomes.

Narrow Complex Tachycardia.

This case report presents the electrocardiogram findings of a patient in their 50s with sudden onset, severe palpitations lasting for 2 hours.

High-Frequency Low-Tidal Volume Ventilation Improves Long-Term Outcomes in AF Ablation: A Multicenter Prospective Study.

BACKGROUND: High-frequency, low-tidal-volume (HFLTV) ventilation is a safe and simple strategy to improve catheter stability and first-pass isolation during pulmonary vein (PV) isolation. However, the impact of this technique on long-term clinical outcomes has not been determined. OBJECTIVES: This study sought to assess acute and long-term outcomes of HFLTV ventilation compared with standard ventilation (SV) during radiofrequency (RF) ablation of paroxysmal atrial fibrillation (PAF). METHODS: In this prospective multicenter registry (REAL-AF), patients undergoing PAF ablation using either HFLTV or SV were included. The primary outcome was freedom from all-atrial arrhythmia at 12 months. Secondary outcomes included procedural characteristics, AF-related symptoms, and hospitalizations at 12 months. RESULTS: A total of 661 patients were included. Compared with those in the SV group, patients in the HFLTV group had shorter procedural (66 [IQR: 51-88] minutes vs 80 [IQR: 61-110] minutes; P < 0.001), total RF (13.5 [IQR: 10-19] minutes vs 19.9 [IQR: 14.7-26.9] minutes; P < 0.001), and PV RF (11.1 [IQR: 8.8-14] minutes vs 15.3 [IQR: 12.4-20.4] minutes; P < 0.001) times. First-pass PV isolation was higher in the HFLTV group (66.6% vs 63.8%; P = 0.036). At 12 months, 185 of 216 (85.6%) in the HFLTV group were free from all-atrial arrhythmia, compared with 353 of 445 (79.3%) patients in the SV group (P = 0.041). HLTV was associated with a 6.3% absolute reduction in all-atrial arrhythmia recurrence, lower rate of AF-related symptoms (12.5% vs 18.9%; P = 0.046), and hospitalizations (1.4% vs 4.7%; P = 0.043). There was no significant difference in the rate of complications. CONCLUSIONS: HFLTV ventilation during catheter ablation of PAF improved freedom from all-atrial arrhythmia recurrence, AF-related symptoms, and AF-related hospitalizations with shorter procedural times.

Idiopathic ventricular fibrillation originating from the moderator band.

We report a case of a 59-year-old man with idiopathic ventricular fibrillation storm. Ventricular fibrillation was pause-dependent and triggered by an early-coupled right ventricular premature complex. The characteristic premature beat was mapped and successfully ablated from Purkinje fibers of the moderator band.

Use and Abuse of Internal Cardioverter Defibrillators for Primary Prevention.

Sudden cardiac death (SCD) is one of the leading causes of mortality in developed countries. Internal cardioverter defibrillators (ICDs) have been developed to treat potentially life-threatening ventricular arrhythmias. Multiple randomised trials have been completed to assess the efficacy of primary prevention ICDs in selected populations. In response to the randomised, controlled trials guidelines have been established to help guide physicians in choosing appropriate patients who may benefit from primary prevention ICDs. Unfortunately, many patients who currently fall within the guidelines are either not represented in the clinical trials or disregarded. The morbidity associated with ICD implant is also overlooked and the cost-benefit analyses are exaggerated in favour of ICD implant. This review article summarises major clinical trials addressing primary prevention ICDs, and also highlights the evidence supporting the use and abuse of ICDs.

Analysis of radiation therapy for the control of Merkel cell carcinoma of the head and neck based on 36 cases and a literature review.

Merkel cell carcinoma (MCC) is a rare and aggressive epidermal cancer. We conducted a retrospective study and literature review to investigate the impact that radiation therapy has on local, regional, and distant control as part of the oncologic management of MCC of the head and neck and to further elucidate the role of radiation therapy with regard to regional control for the clinically uninvolved neck. We reviewed all registered cases of head and neck MCC that had occurred at four institutions from January 1988 through December 2005. Treatment and outcomes data were collected on patients with American Joint Committee on Cancer stage I, II, and III tumors. Local, regional, and distant control rates were calculated by comparing variables with the Fisher exact test; Kaplan-Meier analysis was used to report actuarial control data. Stage I to III head and neck MCC was identified in 36 patients-22 men and 14 women, aged 43 to 97 years (mean: 71.6) at diagnosis. Patients with stage I and II tumors were combined into one group, and their data were compared with those of patients with stage III tumors. Twenty-six patients (72%) had clinical stage I/II disease and 10 patients (28%) had clinical stage III disease. Median follow-up was 41 months for the stage I/II group and 19 months for the stage III group. Based on examination at final follow-up visits, local recurrence was seen in 7 of the 36 patients (19%), for a local control rate of 81%. The 2-year actuarial local control rate for all stages of MCC was 83%; by treatment subgroup, the rates were 95% for those who had undergone radiation therapy to the primary site and 69% for those who had not-a statistically significant difference (p = 0.020). Based on information obtained at final follow-ups, 10 of the 36 patients (28%) experienced a regional recurrence, for a regional control rate of 72%. The 2-year actuarial regional control rate among all patients was 70%; by subgroup, rates were 82% for patients who had undergone regional node radiation therapy and 60% for those who had not-not a statistically significant difference (p = 0.225). Nine patients (25%) overall developed a distant metastasis, for a distant control rate of 75%. Salvage therapies included chemotherapy and/or radiation therapy to the metastatic site, but neither had any significant effect on survival. Regardless of treatment, the Kaplan-Meier survival curves leveled off at 30 months with 82% survival for the stage I/II group and at 19 months with 60% survival for the stage III group. We conclude that radiation therapy to the primary tumor site (either following resection or definitively) results in a local control rate of more than 90% in patients with head and neck MCC. We also found a trend toward improved regional control of the clinically negative neck with the addition of radiation therapy.

Do the dietary supplements epigallocatechin gallate or vitamin e cause a radiomodifying response on tumors in vivo? A pilot study with murine breast carcinoma.

The primary aim of this study was to evaluate a systematic and reproducible assay to examine the potential radiomodifying effects of vitamin E (VE) or epigallocatechin gallate (EGCG), antioxidants commonly consumed by cancer patients as dietary supplements, on tumor control. C3H mice were randomized to a control diet or to the control diet supplemented with VE or EGCG. A tumor control dose 50% (TCD(50)) assay was used to evaluate for a radiomodifying response in stage IV murine cancer (MCa-IV) tumors, implanted in the hindleg of mice, and allowed to grow to 8 mm before receiving a single dose of radiation. The effects of VE and EGCG on intratumoral angiogenesis and apoptosis were evaluated in a group of nonirradiated mice using immunohistochemical staining. Cell proliferation assays were conducted on MCa-IV tumors in vitro. EGCG slowed tumor growth rate by 10%. EGCG and VE slowed tumor regrowth by 24 to 25%. There were no significant differences in TCD(50) values between the groups (control = 73.9 Gy, VE = 77.2 Gy, EGCG = 76.4 Gy); however, normal tissues were protected from late radiation effects (autoamputations) in the VE group. VE and EGCG increased tumor cell apoptosis and decreased tumor cell proliferation but had no effect on microvessel density. In this pilot study, neither VE nor EGCG exerted a significant radiomodifying effect on the MCa-IV tumor. Nonetheless, the suggestion of a small degree of tumor radioprotection by these antioxidant compounds warrants further research. As supplementation with VE radioprotected normal tissue, additional studies on this putative benefit are recommended.