Noninvasive epicardial and endocardial mapping of premature ventricular contractions

AIMS: The aim of the present study was to estimate the accuracy of a novel non-invasive epicardial and endocardial electrophysiology system (NEEES) for mapping ectopic ventricular depolarizations. METHODS AND RESULTS: The study enrolled 20 patients with monomorphic premature ventricular contractions (PVCs) or ventricular tachycardia (VT). All patients underwent pre-procedural computed tomography or magnetic resonance imaging of the heart and torso. Radiographic data were semi-automatically processed by the NEEES to reconstruct a realistic 3D model of the heart and torso. In the electrophysiology laboratory, body-surface electrodes were connected to the NEEES followed by unipolar EKG recordings during episodes of PVC/VT. The body-surface EKG data were processed by the NEEES using its inverse-problem solution software in combination with anatomical data from the heart and torso. The earliest site of activation as denoted on the NEEES 3D heart model was compared with the PVC/VT origin using a 3D electroanatomical mapping system. The site of successful catheter ablation served as final confirmation. A total of 21 PVC/VT morphologies were analysed and ablated. The chamber of interest was correctly diagnosed non-invasively in 20 of 21 (95%) PVC/VT cases. In 18 of the 21 (86%) cases, the correct ventricular segment was diagnosed. Catheter ablation resulted in acute success in 19 of the 20 (95%) patients, whereas 1 patient underwent successful surgical ablation. During 6 months of follow-up, 19 of the 20 (95%) patients were free from recurrence off antiarrhythmic drugs. CONCLUSION: The NEEES accurately identified the site of PVC/VT origin. Knowledge of the potential site of the PVC/VT origin may aid the physician in planning a successful ablation strategy

Significant reduction in procedure duration in remote magnetic-guided catheter ablation of atrial fibrillation using the third-generation magnetic navigation system

Purpose: The magnetic navigation system (MNS) has shown to be safe and effective for catheter ablation of atrial fibrillation (AF). However, longer procedure duration as compared to manual catheter ablation may limit its widespread use. This study aimed to assess the impact of the newest generation MNS using an optimized mapping and ablation protocol on the efficacy and safety of remote magnetic catheter (RMC)-guided pulmonary vein isolation (PVI). Methods: This observational study included 52 patients with symptomatic AF who underwent RMC-guided PVI using the second-generation MNS Niobe II (initial 28 patients, group I) or the third-generation MNS Niobe ES in combination with an optimized mapping and ablation protocol (24 patients, group II). Results: Acute PVI was achieved in 26/28 (93%) patients in group I and 24/24 patients (100%) in group II. Mean procedure time was 263.9 ± 81.9 min in group I and significantly lower in group II (139.7 ± 22.6 min, p < 0.01). Mean fluoroscopy time was 18.8 ± 8.7 min in group I and decreased to 7.9 ± 2.6 in group II (p < 0.01). After a median follow-up of 640.5 days (Q1 460.75; Q3 766.5), 16/24 (67%) patients undergoing RMC-guided PVI in group II remained in stable SR. No periprocedural complications were noted for either group. Conclusions: Use of the third-generation MNS for RMC-guided PVI is safe, effective, and drastically reduced procedure times

First insights into cryoballoon-based pulmonary vein isolation taking the individual time-to-isolation into account

Aims Cryoballoon (CB)-based pulmonary vein isolation (PVI) is an established treatment for symptomatic atrial fibrillation (AF). In the present study, we sought to assess the efficacy and safety of CB-based PVI taking the individual time-to-isolation (TTI) into account. Methods and results Sixty consecutive patients with drug-refractory paroxysmal atrial fibrillation [n = 49 (82%)] or short-standing persistent atrial fibrillation [n = 11 (18%)] underwent ablation with a 28-mm second-generation CB. The TTI was assessed by spiral mapping-catheter recordings and subsequently followed by an additional freeze-time of 120 s. No bonus freeze-cycle was applied. If the TTI could not be assessed, a fixed freeze-cycle duration of 240 s was applied and successful PVI confirmed thereafter. Clinical follow-up (FU) included 12-lead ECGs and 24 h Holter-ECGs at 3, 6, and 12 months. A blanking period of 3 months was defined. A total of 239 pulmonary veins (PVs) were identified and successfully isolated. The mean TTI assessed in 170/239 (71%) PVs was 52 ± 32 s. The mean number of CB applications was 1.2 ± 0.5; mean freeze-cycle duration was 192 ± 41 s. Mean procedure and fluoroscopy times were 80 ± 24 min and 16 ± 7 min, respectively. Transient phrenic nerve palsy occurred in one patient (2%). During a mean FU of 405 ± 67 days, 43 patients (72%) remained in stable sinus rhythm. Conclusions Integrating an individual TTI protocol to CB-based PVI results in shorter freeze-cycle applications in a substantial portion of targeted PVs and an arrhythmia-free survival comparable to conventional ablation protocols. The complication rate is low

Association of nutritional risk and adverse medical outcomes across different medical inpatient populations

OBJECTIVE The aim of this study was to examine the prevalence of nutritional risk and its association with multiple adverse clinical outcomes in a large cohort of acutely ill medical inpatients from a Swiss tertiary care hospital. METHODS We prospectively followed consecutive adult medical inpatients for 30 d. Multivariate regression models were used to investigate the association of the initial Nutritional Risk Score (NRS 2002) with mortality, impairment in activities of daily living (Barthel Index <95 points), hospital length of stay, hospital readmission rates, and quality of life (QoL; adapted from EQ5 D); all parameters were measured at 30 d. RESULTS Of 3186 patients (mean age 71 y, 44.7% women), 887 (27.8%) were at risk for malnutrition with an NRS ≥3 points. We found strong associations (odds ratio/hazard ratio [OR/HR], 95% confidence interval [CI]) between nutritional risk and mortality (OR/HR, 7.82; 95% CI, 6.04-10.12), impaired Barthel Index (OR/HR, 2.56; 95% CI, 2.12-3.09), time to hospital discharge (OR/HR, 0.48; 95% CI, 0.43-0.52), hospital readmission (OR/HR, 1.46; 95% CI, 1.08-1.97), and all five dimensions of QoL measures. Associations remained significant after adjustment for sociodemographic characteristics, comorbidities, and medical diagnoses. Results were robust in subgroup analysis with evidence of effect modification (P for interaction < 0.05) based on age and main diagnosis groups. CONCLUSION Nutritional risk is significant in acutely ill medical inpatients and is associated with increased medical resource use, adverse clinical outcomes, and impairments in functional ability and QoL. Randomized trials are needed to evaluate evidence-based preventive and treatment strategies focusing on nutritional factors to improve outcomes in these high-risk patients

An interlaboratory comparison of mid-infrared spectra acquisition: Instruments and procedures matter

Diffuse reflectance spectroscopy has been extensively employed to deliver timely and cost-effective predictions of a number of soil properties. However, although several soil spectral laboratories have been established worldwide, the distinct characteristics of instruments and operations still hamper further integration and interoperability across mid-infrared (MIR) soil spectral libraries. In this study, we conducted a large-scale ring trial experiment to understand the lab-to-lab variability of multiple MIR instruments. By developing a systematic evaluation of different mathematical treatments with modeling algorithms, including regular preprocessing and spectral standardization, we quantified and evaluated instruments' dissimilarity and how this impacts internal and shared model performance. We found that all instruments delivered good predictions when calibrated internally using the same instruments' characteristics and standard operating procedures by solely relying on regular spectral preprocessing that accounts for light scattering and multiplicative/additive effects, e.g., using standard normal variate (SNV). When performing model transfer from a large public library (the USDA NSSC-KSSL MIR library) to secondary instruments, good performance was also achieved by regular preprocessing (e.g., SNV) if both instruments shared the same manufacturer. However, significant differences between the KSSL MIR library and contrasting ring trial instruments responses were evident and confirmed by a semi-unsupervised spectral clustering. For heavily contrasting setups, spectral standardization was necessary before transferring prediction models. Non-linear model types like Cubist and memory-based learning delivered more precise estimates because they seemed to be less sensitive to spectral variations than global partial least square regression. In summary, the results from this study can assist new laboratories in building spectroscopy capacity utilizing existing MIR spectral libraries and support the recent global efforts to make soil spectroscopy universally accessible with centralized or shared operating procedures.ISSN:0016-7061ISSN:1872-625