Therapeutic end points for the treatment of atrioventricular node reentrant tachycardia by catheter-guided radiofrequency current

AbstractObjectives. The purpose off this prospective study was to test the hypothesis that the elimination of inducible repetitive atrioventricular (AV) node reentry the persistence of slow AV pathway conduction is a valid end point for radiofrequency catheter ablation procedures in patients with supraventricular tachycardia due to AV node reentry.Background. Although modification of AV node physiology by radiofrequency current can eliminate AV node reentrant tachycardia, therapeutic end points that are definitive of a satisfactory result in patients undergoing modification of the slow AV pathway have not been established. Applications of radiofrequency current at selected sites may eliminate all evidence of slow pathway conduction or sufficiently modify the refractory properties of the slow pathway to preclude sustained arrhythmias. Accordingly, total abolition of dual AV node physiology may not be necessary to prevent arrhythmia recurrence.Methods. Radiofrequency catheter ablation of the slow AV pathway was attempted in 59 patients with typical AV node reentry. Tissue ablation was performed with a continuous wave of 500-kHz radiofrequency current. Twenty-five to 35 W was applied for 60 s at the site selected for destruction.Results. Dual AV node physiology was eliminated completely in 35 patients (59%), persisted without inducible AV node reentry in 13 patients (22%) and persisted with inducible single AV reentrant beats in 11 patients (19%). In patients with persistent dual AV node physiology, the maximal difference between the effective refractory period of the fast and slow pathways was reduced from 104 ± 62 ms before the procedure to 37 ± 37 ms after AV conduction had been modified (p < 0.001). During a mean follow-up interval of 15 months (range 4 to 28), only one patient (2%) had a recurrence of the tachycardia.Conclusions. Resulte demonstrate that when complete elimination of dial AV node physiology is difficult, modification of slow pathway conduction to the extent that repetitive AV node reentry cannot be induced is a definitive end point that portends a good prognosis

REDUCE-IT USA: Results From the 3146 Patients Randomized in the United States.

BackgroundSome trials have found that patients from the United States derive less benefit than patients enrolled outside the United States. This prespecified REDUCE-IT (Reduction of Cardiovascular Events with Icosapent Ethyl - Intervention Trial) subgroup analysis was conducted to determine the degree of benefit of icosapent ethyl in the United States.MethodsREDUCE-IT randomized 8179 statin-treated patients with qualifying triglycerides ≥135 and &lt;500 mg/dL and low-density lipoprotein cholesterol &gt;40 and ≤100 mg/dL and a history of atherosclerosis or diabetes mellitus to icosapent ethyl 4 g/d or placebo. The primary composite end point was cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, coronary revascularization, or hospitalization for unstable angina. The key secondary composite end point was cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke. A hierarchy was prespecified for examination of individual and composite end points.ResultsA total of 3146 US patients (38.5% of the trial) were randomized and followed for a median of 4.9 years; 32.3% were women and 9.7% were Hispanic. The primary composite end point occurred in 24.7% of placebo-treated patients versus 18.2% of icosapent ethyl-treated patients (hazard ratio [HR], 0.69 [95% CI, 0.59-0.80]; P=0.000001); the key secondary composite end point occurred in 16.6% versus 12.1% (HR, 0.69 [95% CI, 0.57-0.83]; P=0.00008). All prespecified hierarchical end points were meaningfully and significantly reduced, including cardiovascular death (6.7% to 4.7%; HR, 0.66 [95% CI, 0.49-0.90]; P=0.007), myocardial infarction (8.8% to 6.7%; HR, 0.72 [95% CI, 0.56-0.93]; P=0.01), stroke (4.1% to 2.6%; HR, 0.63 [95% CI, 0.43-0.93]; P=0.02), and all-cause mortality (9.8% to 7.2%; HR, 0.70 [95% CI, 0.55-0.90]; P=0.004); for all-cause mortality in the US versus non-US patients, Pinteraction=0.02. Safety and tolerability findings were consistent with the full study cohort.ConclusionsWhereas the non-US subgroup showed significant reductions in the primary and key secondary end points, the US subgroup demonstrated particularly robust risk reductions across a variety of individual and composite end points, including all-cause mortality.Clinical trial registrationURL: https://www.clinicaltrials.gov. Unique identifier: NCT01492361

Напряженное состояние призабойной части массива при проведении горных выработок с конической формой забоя

У рамках механіки пружно-деформованого тіла розроблена методика та розв’язана задача про напружений стан гірського масиву навколо горизонтальної циліндричної виробки. Чисельними дослідженнями виявлено значну концентрацію розтягуючих напружень у зоні ведення гірничих робіт.A method of stress state of a rock massif near the horizontal cylindrical working is developed, and a problem of mechanics of elastically deformed bodies is solved. A considerable concentration of tensile stresses in the mining working zone is revealed by numerical calculations

Two-Component Direct Fluorescent-Antibody Assay for Rapid Identification of Bacillus anthracis

A two-component direct fluorescent-antibody (DFA) assay, using fluorescein-labeled monoclonal antibodies specific to the Bacillus anthracis cell wall (CW-DFA) and capsule (CAP-DFA) antigens, was evaluated and validated for rapid identification of B. anthracis. We analyzed 230 B. anthracis isolates; 228 and 229 were positive by CW-DFA and CAP-DFA assays, respectively. We also tested 56 non–B. anthracis strains; 10 B. cereus and 2 B. thuringiensis were positive by the CW-DFA assay, and 1 B. megaterium strain was positive by CAP-DFA. Analysis of the combined DFA results identified 227 of 230 B. anthracis isolates; all 56 strains of the other Bacillus spp. were negative. Both DFA assays tested positive on 14 of 26 clinical specimens from the 2001 anthrax outbreak investigation. The two-component DFA assay is a sensitive, specific, and rapid confirmatory test for B. anthracis in cultures and may be useful directly on clinical specimens

HRS/EHRA/APHRS/LAHRS/ACC/AHA worldwide practice update for telehealth and arrhythmia monitoring during and after a pandemic

Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), started in the city of Wuhan late in 2019. Within a few months, the disease spread toward all parts of the world and was declared a pandemic on March 11, 2020. The current health care dilemma worldwide is how to sustain the capacity for quality services not only for those suffering from COVID-19 but also for non-COVID-19 patients, all while protecting physicians, nurses, and other allied health care workers