Intercomparison IC2021area of passive area dosimetry systems

The EURADOS intercomparison IC2021area was carried out between May 2021 and April 2022 for 66 participating passive H*(10) area dosimetry systems from 47 different institutes and monitoring services. Three measurement conditions were provided at locations of the Karlsruhe Institute of Technology: 3-months indoor, 3-months outdoor and 6-months outdoor. The challenge of this intercomparison was measuring additionally irradiated low dose radiation. Six dosemeters of each participating system were irradiated with Cs-137 gamma reference radiation: Three dosemeters with 150 µSv and three dosemeters with 300 µSv. Another six dosemeters of each participating system were not irradiated and were used for background dose subtraction. Typical values of the measured background dose were between 200 µSv and 450 µSv with a few significantly higher values up to 1.6 mSv. Despite the challenge of the low reference dose values, more than 90 % of the resulting response values of the irradiated dosemeters were within the recommended ISO 14146 trumpet curve response limits.Peer ReviewedPostprint (published version

Chronic Heart Failure and Exercise Intolerance: The Hemodynamic Paradox

Heart failure represents a major source of morbidity and mortality in industrialized nations. As the leading hospital discharge diagnosis in the United States in patients over the age of 65, it is also associated with substantial economic costs. While the acute symptoms of volume overload frequently precipitate inpatient admission, it is the symptoms of chronic heart failure, including fatigue, exercise intolerance and exertional dyspnea, that impact quality of life. Over the last two decades, research into the enzymatic, histologic and neurohumoral alterations seen with heart failure have revealed that hemodynamic derangements do not necessarily correlate with symptoms. This “hemodynamic paradox” is explained by alterations in the skeletal musculature that occur in response to hemodynamic derangements. Importantly, gender specific effects appear to modify both disease pathophysiology and response to therapy. The following review will discuss our current understanding of the systemic effects of heart failure before examining how exercise training and cardiac resynchronization therapy may impact disease course

Ablation of Stable VTs Versus Substrate Ablation in Ischemic Cardiomyopathy the VISTA Randomized Multicenter Trial

Background Catheter ablation reduces ventricular tachycardia (VT) recurrence and implantable cardioverter defibrillator shocks in patients with VT and ischemic cardiomyopathy. The most effective catheter ablation technique is unknown. Objectives This study determined rates of VT recurrence in patients undergoing ablation limited to clinical VT along with mappable VTs ("clinical ablation") versus substrate-based ablation. Methods Subjects with ischemic cardiomyopathy and hemodynamically tolerated VT were randomized to clinical ablation (n = 60) versus substrate-based ablation that targeted all "abnormal" electrograms in the scar (n = 58). Primary endpoint was recurrence of VT. Secondary endpoints included periprocedural complications, 12-month mortality, and rehospitalizations. Results At 12-month follow-up, 9 (15.5%) and 29 (48.3%) patients had VT recurrence in substrate-based and clinical VT ablation groups, respectively (log-rank p < 0.001). More patients undergoing clinical VT ablation (58%) were on antiarrhythmic drugs after ablation versus substrate-based ablation (12%; p < 0.001). Seven (12%) patients with substrate ablation and 19 (32%) with clinical ablation required rehospitalization (p = 0.014). Overall 12-month mortality was 11.9%; 8.6% in substrate ablation and 15.0% in clinical ablation groups, respectively (log-rank p = 0.21). Combined incidence of rehospitalization and mortality was significantly lower with substrate ablation (p = 0.003). Periprocedural complications were similar in both groups (p = 0.61). Conclusions An extensive substrate-based ablation approach is superior to ablation targeting only clinical and stable VTs in patients with ischemic cardiomyopathy presenting with tolerated VT