European survey on efficacy and safety of duty-cycled radiofrequency ablation for atrial fibrillation.

AIMS: Duty-cycled radiofrequency ablation (RFA) has been used for atrial fibrillation (AF) for around 5 years, but large-scale data are scarce. The purpose of this survey was to report the outcome of the technique. METHODS AND RESULTS: A survey was conducted among 20 centres from seven European countries including 2748 patients (2128 with paroxysmal and 620 with persistent AF). In paroxysmal AF an overall success rate of 82% [median 80%, interquartile range (IQR) 74-90%], a first procedure success rate of 72% [median 74% (IQR 59-83%)], and a success of antiarrhythmic medication of 59% [median 60% (IQR 39-72%)] was reported. In persistent AF, success rates were significantly lower with 70% [median 74% (IQR 60-92%)]; P = 0.05) as well as the first procedure success rate of 58% [median 55% (IQR 47-81%)]; P = 0.001). The overall success rate was similar among higher and lower volume centres and were not dependent on the duration of experience with duty-cycled RFA (r = -0.08, P = 0.72). Complications were observed in 108 (3.9%) patients, including 31 (1.1%) with symptomatic transient ischaemic attack or stroke, which had the same incidence in paroxysmal and persistent AF (1.1 vs. 1.1%) and was unrelated to the case load (r = 0.24, P = 0.15), bridging anticoagulation to low molecular heparin, routine administration of heparin over the long sheath, whether a transoesophageal echocardiogram was performed in every patient or not and average procedure times. CONCLUSION: Duty-cycled RFA has a self-reported success and complication rate similar to conventional RFA. After technical modifications a prospective registry with controlled data monitoring should be conducted to assess outcome.

Response analysis of stimulating efficacy of polihexanide in an in vitro wound model with respiratory ciliary epithelial cells.

In animal wound models, accelerated wound closure has been shown by use of polihexanide applied in antimicrobially effective concentrations. Additionally, an increased ATP production of keratinocytes in vitro induced by polihexanide was demonstrated and interpreted as a stimulatory effect on cell proliferation. Based on these results and the clinical reports on improved wound healing after introduction of polihexanide for preoperative antisepsis in the nasal cavity, polihexanide was tested in a wound model on respiratory ciliary epithelial cells allowing measurement of the healing process after artificial injury. 0.5 µg/ml polihexanide accelerated wound healing in terms of proliferation and migration significantly after an exposure time of 1 and 96 h. At a concentration of 1 µg/ml polihexanide, the stimulation of wound healing was significantly increased only after an exposure time of 96 h. This is the first study to demonstrate acceleration of wound healing in a standardized in vitro model using an epithelial cell line. Considering the present results and previous reports on the impact of polihexanide on wound healing, the conclusion is drawn that the positive effect of polihexanide on wound healing is a separate, dose-dependent effect independent of its antiseptic properties.

Therapeutic drug monitoring-guided high dose meropenem therapy of a multidrug resistant Acinetobacter baumannii - A case report.

BACKGROUND: Infections with multidrug resistant Acinetobacter baumannii in immunocompromised patients are life-threatening. Therapeutic options are rare in this context, but patients are dependent on an effective antibiotic therapy. Thus, new antibiotic strategies are deemed necessary. CASE PRESENTATION: This case report recounts the therapeutic drug monitoring-guided meropenem therapy of a 32 years old patient admitted with acute exacerbation of cystic fibrosis. Veno-venous extracorporeal membrane oxygenation was initiated on the first day of admission to the intensive care unit. The patient showed insufficient serum trough levels of meropenem despite the maximum approved dose (2g every 8h) was administered which was due to augmented renal clearance. Through continuous infusion of the same cumulative dose, target levels were reached. On day 17 of admission, the patient underwent successful double-lung-transplant surgery and extracorporeal membrane oxygenation was ended. Unfortunately, the donor's lung was colonized with a multidrug resistant Acinetobacter baumannii that was positive for OXA-23 carbapenemase. Hence a combination therapy of intravenous sulbactam, tigecycline, meropenem and inhalative colistin was established, with a known minimal inhibitory concentration for meropenem of 32 mg/l. Under continuous infusion of 8 g meropenem/day, serum levels exceeded 32 mg/l over 12 days. The patient was transferred from the intensive care unit to a general ward without any signs of infection. CONCLUSIONS: Therapeutic drug monitoring-guided meropenem may be a sound new therapeutic option in eradicating multidrug resistant Acinetobacter and offer a novel therapeutic option in the field of personalized medicine.

The ONTAI study - a survey on antimicrobial dosing and the practice of therapeutic drug monitoring in German intensive care units.

PURPOSE: Optimization of antibiotic therapy is still urgently needed in critically ill patients. The aim of the ONTAI survey (online survey on the use of Therapeutic Drug Monitoring of antibiotics in intensive care units) was to evaluate which strategies intensive care physicians in Germany use to improve the quality of antibiotic therapy and what role a Therapeutic Drug Monitoring (TDM) plays. METHODS: Among the members of the German Society for Anaesthesiology and the German Society for Medical Intensive Care Medicine and Emergency Medicine, a national cross-sectional survey was conducted using an online questionnaire. RESULTS: The questionnaire was completely answered by 398 respondents. Without TDM, prolonged infusion was judged to be the most appropriate dosing regimen for beta lactams. A TDM for piperacillin, meropenem and vancomycin was performed in 17, 22 and 75% of respondents, respectively. For all beta lactams, a TDM was requested more often than it was available. There was great uncertainty as to the optimal pharmacokinetic/pharmacodynamic index for beta-lactams. 86% of the respondents who received minimal inhibitory concentrations adapted the therapy accordingly. CONCLUSION: German intensive care physicians are convinced of TDM for dose optimization. However, practical implementation, the determination of MICs and defined target values are still lacking.

Determination of the inferior border of the thecal sac using magnetic resonance imaging: implications on radiation therapy treatment planning.

PURPOSE: To determine whether the traditional teaching of placing the caudal border of the spinal field at the S2-S3 interspace in children receiving craniospinal irradiation (CSI) is appropriate. METHODS AND MATERIALS: Twenty-three children had magnetic resonance imaging (MRI) of the spine with gadolinium prior to craniospinal irradiation at one institution. Thecal sac termination using MRI was determined by drawing a perpendicular line from the point of convergence of dural margins to the corresponding vertebral body. RESULTS: Location of thecal sac termination varied from mid-S1 to low S3 vertebral body, with the most frequent site at the upper S2 vertebral level. Only 2 of 23 (8.7%) children had thecal sac terminations below the S2-S3 interspace. For the nine patients with neuraxis disease, none had thecal sac terminations below the S2-S3 interspace. In seven of the nine patients who had neuraxis seeding at initial presentation, MRI of the spine after CSI was performed and showed that thecal sac termination was lower after radiation therapy in two children, higher in one, and the same in four. CONCLUSIONS: In 2 of 23 children (8.7%), placement of the inferior border at the bottom of the S2 vertebral body would have missed the entire thecal sac. Treatment to the entire neuraxis with adequate coverage of distal spinal theca can be achieved by using MRI. Individualized spinal fields using the MRI may help minimize radiation scatter to the gonads while adequately covering the target volume.

Sudden cardiac death after coronary artery bypass grafting is not predicted by signal-averaged ECG.

BACKGROUND: Sudden cardiac death (SCD) is a major cause of death despite successful revascularization in patients with coronary artery disease. The signal-averaged ECG (SAECG) is a sensitive predictor of SCD and could be used in the screening strategy to select patients for prophylactic cardioverter implantation. METHODS: The SAECG was recorded in 561 patients (mean age: 60 +/- 8.8 years) within 10 days of coronary artery bypass grafting. Signal-averaged ECG was performed with a bandpass filtering of 40 to 250 Hz for more than 250 beats until a noise level of 0.6 microV was achieved. All patients were followed for 5.5 +/- 1.2 years after the procedure. RESULTS: Preoperative angiographic ejection fraction was at least 60% in 393 patients (72%), 40% to 60% in 126 patients (23%), and 40% or less in 28 patients (5%). There were 34 deaths, 10 of which were SCD. Late potentials were found in a total of 150 patients (27%) and were equally frequent preoperatively and postoperatively and among patients with (30%) and without (27%) SCD. The only predictors for overall mortality were age and a reduced ejection fraction. CONCLUSIONS: Signal-averaged ECG did not predict prognosis in low-risk patients undergoing coronary artery bypass grafting.

[Stress, depression and cardiac arrhythmias]. / Stress, Depression und kardiale Arrhythmien.

A relationship between behavioural factors and cardiac arrhythmogenesis in humans has been described. Three sets of conditions contribute to the occurrence of arrhythmias: myocardial electrical instability, most often due to coronary artery disease; an acute triggering event, frequently related to mental stress; and a chronic, pervasive, and intense psychological state, often including depression and hopelessness. The autonomic nervous system plays an important role in the occurrence of cardiac arrhythmias and it is well documented that mood alterations as mental stress and depression influence cardiac autonomic balance. There is an increasing body of evidence that patients with the greatest changes in cardiac neural regulation with decreased parasympathetic tone coupled with increased sympathetic activity are at the greatest risk for developing fatal ventricular arrhythmias. These patients have a reduced heart rate variability, increased QT-dispersion and a decreased baroreceptor sensitivity. The influence of stress and depression on the autonomic nervous system and the impact on the occurrence of both atrial and ventricular arrhythmias is being discussed.

[Heart transplantation: indications and results]. / Indikationen und Erfolge der Herztransplantation.

Heart transplantation has been established as therapy in patients with terminal heart failure who remain severely symptomatic (NYHA III-IV) despite optimal drug therapy and surgical interventions other than transplantation. In addition to symptoms, various objective criteria are used to determine the patients most suitable for transplantation. Of these, peak oxygen consumption below 12-14 ml/kg/min, no irreversibly elevated pulmonary resistance, and no major concomitant disease are most important. However, conventional therapy of advanced heart failure has considerably improved over the last decade. Thus, heart transplantation may be avoided or at least postponed in many patients. Nevertheless, continuous treatment at a heart failure/heart transplantation clinic in collaboration with the general practitioner is essential in these patients. This may allow to closely monitor these severely ill patients and to select the optimal point of time for transplantation. Prognosis after heart transplantation is relatively good with a 10-year survival of 63%. However, graft coronary artery disease and lymphomas are still unresolved problems which limit the success of heart transplantation. Competent clinical monitoring, aggressive therapy of conventional risk factors and good co-operation of patients and doctors are the basis for a successful outcome.

Pectus excavatum: echocardiography and cardiac MRI reveal frequent pericardial effusion and right-sided heart anomalies.

AIMS: In patients with pectus excavatum (PEX), echocardiographic assessment can be difficult. There are little data on the impact of the chest deformity on echocardiographic findings and comparison of data obtained by echocardiography (echo) with cardiac magnetic resonance imaging (CMR) in PEX. METHODS AND RESULTS: In a prospective study, cardiac anomalies in PEX were analysed by echo and compared with CMR in consecutive patients with PEX referred for echo. If they agreed to participate, the patients were referred for CMR and included if the pectus index was ≥3.0 by CMR. Also, clinical data and electrocardiogram tracings were analysed. There were 18 patients (13 females; 72%), with a mean age of 53±16 years; mean pectus index was 4.7 (range: 3-7.3). Echo showed haemodynamically insignificant pericardial effusion in six patients (33%), tricuspid valve prolapse in five (28%), right ventricular (RV) localized wall motion anomalies (WMA) in five (28%) and diminished RV systolic function in two (11%); no patient had RV dilatation. CMR demonstrated cardiac displacement to the left in 9 patients (50%); minimal pericardial effusion was seen in 10 patients (56%; P value=0.13 compared with echo), RV localized WMA in 6 (44%; P value=1.0), diminished RV systolic function in 8 (44%; P=0.07), and RV dilatation in 5 (28%; P=0.06). A completely normal cardiac examination was found in six patients by echo (33%) and in 2 (11%) using CMR. Although some signs of arrhythmogenic RV cardiomyopathy (ARVC) were present, no patient fulfilled the ARVC criteria. CONCLUSION: In severe PEX, haemodynamically insignificant pericardial effusion, tricuspid valve prolapse and other RV anomalies possibly due to RV displacement are frequent as demonstrated by both CMR and echo. The cardiac assessment by echo and CMR did show discrepancies; however, they were not significant.

[Atrial flutter and fibrillation]. / Vorhofflimmern und Vorhofflattern.

This article summarizes current understandings and therapies for both arrhythmias. Atrial flutter is most often arising from a macroreentry circuit in the right atrium or around scar tissue in case or previous cardiothoracic surgery. As a macroreentrant tachycardia it is regular and can lead to higher heart rates, especially if occurring with 1:1 conduction. In contrast atrial fibrillation, especially when occurring paroxysmal at the beginning, is arising from triggers within the pulmonary veins. Ablation strategies to electrically isolate those triggers have a treatment success rate of 80%, which is much more than can be achieved with antiarrhythmic medication (success rates 30-50%). Emergency treatment of both arrhythmias include cardioversion and pacemaker implantation with AV node ablation if necessary.

Alkaline proteins of Bacillus subtilis: first steps towards a two-dimensional alkaline master gel.

The genomic sequence of Bacillus subtilis, which is the best studied Gram-positive bacterium, enabled us to obtain a theoretical two-dimensional (2-D) map, demonstrating that about one-third of this proteome has a theoretical alkaline isoelectric point (pI). This represents an important part of the entire proteome, which is not detectable in conventional 2-D gels (pH range 4-7). Sequence analysis revealed that 91% of the ribosomal proteins and a high amount of theoretical membrane proteins should be localized in the alkaline pH range requiring different protein extraction procedures. In order to find the pH range which gives the best resolution results for the alkaline proteins of B. subtilis, immobilized pH gradients (IPGs) with different pH ranges (pH 6-10, 6-11, 4-12, 9-12, and 3-10) were tested and optimized for IPG 4-12. Here we present a version of a first alkaline master 2-D gel for B. subtilis, which is a further complement of the already existing master gel (pH 4-7) in the Sub2D database. Almost 150 spots could be detected and 41 proteins have already been identified.

Phosphate starvation-inducible proteins of Bacillus subtilis: proteomics and transcriptional analysis.

The phosphate starvation response in Bacillus subtilis was analyzed using two-dimensional (2D) polyacrylamide gel electrophoresis of cell extracts and supernatants from phosphate-starved cells. Most of the phosphate starvation-induced proteins are under the control of sigma(B), the activity of which is increased by energy depletion. In order to define the proteins belonging to the Pho regulon, which is regulated by the two-component regulatory proteins PhoP and PhoR, the 2D protein pattern of the wild type was compared with those of a sigB mutant and a phoR mutant. By matrix-assisted laser desorption ionization-time of flight mass spectrometry, two alkaline phosphatases (APases) (PhoA and PhoB), an APase-alkaline phosphodiesterase (PhoD), a glycerophosphoryl diester phosphodiesterase (GlpQ), and the lipoprotein YdhF were identified as very strongly induced PhoPR-dependent proteins secreted into the extracellular medium. In the cytoplasmic fraction, PstB1, PstB2, and TuaD were identified as already known PhoPR-dependent proteins, in addition to PhoB, PhoD, and the previously described PstS. Transcriptional studies of glpQ and ydhF confirmed the strong PhoPR dependence. Northern hybridization and primer extension experiments showed that glpQ is transcribed monocistronically from a sigma(A) promoter which is overlapped by four putative TT(A/T)ACA-like PhoP binding sites. Furthermore, ydhF might be cotranscribed with phoB initiating from the phoB promoter. Only a small group of proteins remained phosphate starvation inducible in both phoR and sigB mutant and did not form a unique regulation group. Among these, YfhM and YjbC were controlled by sigma(B)-dependent and unknown PhoPR-independent mechanisms. Furthermore, YtxH and YvyD seemed to be induced after phosphate starvation in the wild type in a sigma(B)-dependent manner and in the sigB mutant probably via sigma(H). YxiE was induced by phosphate starvation independently of sigma(B) and PhoPR.

Dual channel imaging of two-dimensional electropherograms in Bacillus subtilis.

The allocation of proteins to stimulons and regulons is an essential step towards the understanding of the global regulation of the expression of entire genomes. The computer-aided evaluation and matching of two-dimensional protein gels loaded with radioactively labeled proteins from exponentially growing or stressed cells is a useful but time-consuming procedure for the description of stimulons and regulons. This paper describes the dual-channel image analysis that offers the opportunity to visualize the content and synthesis rate of a whole set of bacterial proteins on a single electropherogram. By pulse-labeling with L-[35S]methionine, the protein synthesis pattern (red color) can be directly compared with the protein level pattern (green color). Because matching of other gels can be avoided, this new technique is useful for the rapid search for proteins that belong to different stimulons or regulons. This approach was tested for the identification of proteins of heat stress or oxidative stress stimulons. Proteins that were induced by heat or oxidative stress colored red while proteins whose synthesis was switched off by the stress factor colored green. Proteins that were continuously synthesized before and after the imposition of stress retained their yellow color. The advantages and possible pitfalls of the technique are discussed.

[Cholestatic jaundice and pruritus]. / Cholestatischer Ikterus und Pruritus.

The 38 year old male patient was admitted to our clinic with jaundice and invalidating pruritus of unknown origin. The primary evaluation made by the practitioner of the patient and the initial examinations performed in the clinic revealed no diagnosis. In particular, an infectious liver disease could be excluded. Reevaluation of anamnestic data revealed then the in-take of Dianabol, an often used anabolic steroid as the most possible reason for the cholestatic hepatopathy.