Pump-probe capabilities at the SPB/SFX instrument of the European XFEL.

Pump-probe experiments at X-ray free-electron laser (XFEL) facilities are a powerful tool for studying dynamics at ultrafast and longer timescales. Observing the dynamics in diverse scientific cases requires optical laser systems with a wide range of wavelength, flexible pulse sequences and different pulse durations, especially in the pump source. Here, the pump-probe instrumentation available for measurements at the Single Particles, Clusters, and Biomolecules and Serial Femtosecond Crystallography (SPB/SFX) instrument of the European XFEL is reported. The temporal and spatial stability of this instrumentation is also presented.

[Interruption of cardiac resynchronization therapy after a ventricular premature beat : What is the mechanism?] / Unterbrechung der kardialen Resynchronisationstherapie nach ventrikulärer Extrasystolie : Was ist der Mechanismus?

The present case report illustrates a mechanism that can interrupt cardiac resynchronization therapy (CRT) and lead to recurrence of dyspnea during exercise. It points out that CRT requires a regular cardiac history, analysis of device-stored data and profound knowledge about function and especially timing intervals of these systems in order to utilize the full potential of this therapy.

Effectiveness of a percutaneous left ventricular assist device in preventing acute hemodynamic decompensation during catheter ablation of ventricular tachycardia in advanced heart failure patients: A retrospective single-center analysis.

INTRODUCTION: Acute hemodynamic decompensation during catheter ablation of ventricular tachycardia is associated with increased mortality. We assessed the effectiveness of mechanical circulatory support using a micro-axial percutaneous assist device in preventing acute hemodynamic decompensation. METHODS AND RESULTS: Twenty-six consecutive patients with structural heart disease undergoing 28 ventricular tachycardia ablations between May 2013 and October 2017 were included. All patients presenting with left ventricular ejection fraction <25%, symptomatic heart failure and arrhythmia associated hemodynamic decompensation underwent catheter ablation with mechanical circulatory support (Impella 2.5; Impella CP, Abiomed, Danvers, MA). Electro-anatomic mapping was performed using Ensite NavX (Abbott, Chicago, IL) or Rhythmia (Boston Scientific, Marlborough, MA) mapping systems. Mapping/ablation strategy included a substrate and activation mapping/ablation. Of the 26 patients, 80% had ischemic cardiomyopathy, the mean age was 68 ± 9 years; mean left ventricular ejection fraction 19.6% ± 3%, mean PAAINESD score was 21 ± 3. Mean tachycardia cycle length was 348 ± 76 ms (range 280-500 ms). The assist device was used pre-emptively in 25 patients and as rescue therapy in one patient. All ventricular tachycardias occurring during substrate ablation were activation mapped and ablated. The ablation procedure was accomplished in 25 of 26 patients, acute decompensation occurred only in one patient receiving circulatory support as bail-out therapy. CONCLUSION: In patients with advanced heart failure and a high probability of acute hemodynamic decompensation during catheter ablation, mechanical circulatory support prevented acute decompensation in 25 of 26 patients. Thus, mechanical circulatory support facilitates catheter ablation of unstable ventricular tachycardia in a critically ill patient population.

Effectiveness of single- vs dual-coil implantable defibrillator leads: An observational analysis from the SIMPLE study.

INTRODUCTION: Dual-coil leads (DC-leads) were the standard of choice since the first nonthoracotomy implantable cardioverter/defibrillator (ICD). We used contemporary data to determine if DC-leads offer any advantage over single-coil leads (SC-leads), in terms of defibrillation efficacy, safety, clinical outcome, and complication rates. METHODS AND RESULTS: In the Shockless IMPLant Evaluation study, 2500 patients received a first implanted ICD and were randomized to implantation with or without defibrillation testing. Two thousand and four hundred seventy-five patients received SC-coil or DC-coil leads (SC-leads in 1025/2475 patients; 41.4%). In patients who underwent defibrillation testing (n = 1204), patients with both lead types were equally likely to achieve an adequate defibrillation safety margin (88.8% vs 91.2%; P = 0.16). There was no overall effect of lead type on the primary study endpoint of "failed appropriate shock or arrhythmic death" (adjusted HR 1.18; 95% CI, 0.86-1.62; P = 0.300), and on all-cause mortality (SC-leads: 5.34%/year; DC-leads: 5.48%/year; adjusted HR 1.16; 95% CI, 0.94-1.43; P = 0.168). However, among patients without prior heart failure (HF), and SC-leads had a significantly higher risk of failed appropriate shock or arrhythmic death (adjusted HR 7.02; 95% CI, 2.41-20.5). There were no differences in complication rates. CONCLUSION: In this nonrandomized evaluation, there was no overall difference in defibrillation efficacy, safety, outcome, and complication rates between SC-leads and DC-leads. However, DC-leads were associated with a reduction in the composite of failed appropriate shock or arrhythmic death in the subgroup of non-HF patients. Considering riskier future lead extraction with DC-leads, SC-leads appears to be preferable in the majority of patients.

Left atrial appendage closure with the Amplatzer™ Cardiac Plug: Rationale for a higher degree of device oversizing at implantation.

BACKGROUND: In left atrial appendage (LAA) closure, the correct sizing of the implantable devices is crucial. Data on the time-dependent changes in the shape and positioning of LAA occlusion devices are missing. We analyzed the results of 33 consecutive patients after implantation of an Amplatzer™ Cardiac Plug (ACP) LAA closure device to get more information on the optimal device sizing during implantation. METHODS AND RESULTS: Thirty-three consecutive patients were enrolled in this observational study. ACP implantation was guided by fluoroscopy and three dimensional transesophageal echocardiography (3-D TEE). Device sizing was based on the largest measured diameter of the intended landing zone adding 2-4 mm of device oversizing. Fluoroscopies were performed at 1 day after, and after 3 months, control 3-D TEE was performed 3 months after implantation. The stability of device positioning and shape was matched with the results of 3-D TEE. Patients' mean age was 70.2 ± 8 years; mean CHA2DS2VASc score was 3.8 ± 1.1. According to the manufacture's classification, the post-implant degree of compression of the device-lobe was classified in three categories 1) undercompression "square-like shape" (1 patient); 2) optimal compression "tire-like shape" (20 patients), 3) overcompression "strawberry-like shape" (12 patients). Changes in the degree of device compression by more than one classification class occurred in 18/33 of our patients. A complete loss of device compression ("square-like shape") was observed in 9 patients. Despite the changes in device compression, a complete closure of the LAA was achieved in 32/33 patients. CONCLUSIONS: There is a temporal change in shape and positioning of the ACP within 3 months after implantation. A late decompression of the ACP lobe was observed in 61% of our patients, leading to a complete loss in device compression in 27%. This observation may be the rationale for a higher degree of ACP oversizing during implantation.

Laryngeal tube placement on manikin by laypersons: is there a possibility for 'public access airway management'?

Mouth-to-mouth ventilation is often refused by laypersons because of hygienic reasons. Supraglottic airway devices (SADs) might reduce the adverse effects of mouth-to-mouth ventilation. We tried to verify the possibility for untrained laypersons to use SADs properly after having read written instructions only. The participants were told to ventilate a manikin using a laryngeal tube (LT). The time to ventilation and the rate of success were recorded. After a practical skill demonstration, a second placement of the LT was performed. A successful placement of the LT was achieved by 53% after the first and 98% after the second attempt. Time to ventilation was 124 s (±45 s) for the first attempt and 12 s (±2.75 s) for the second attempt. Delivering ventilation through an SAD is a reasonable way for laypersons. After a prior hands-on training, the placement can be performed in an adequate time frame with high success rates.