[Prevention of bicycle accidents]. / Prävention von Fahrradfahrerunfällen.

For a very precise analysis of all injured bicyclists in Germany it would be important to have definitions for "severely injured", "seriously injured" and "critically injured". By this, e.g., two-thirds of surgically treated bicyclists who are not registered by the police could become available for a general analysis. Elderly bicyclists (> 60 years) are a minority (10 %) but represent a majority (50 %) of all fatalities. They profit most by wearing a helmet and would be less injured by using special bicycle bags, switching on their hearing aids and following all traffic rules. E-bikes are used more and more (145 % more in 2012 vs. 2011) with 600,000 at the end of 2011 and are increasingly involved in accidents but still have a lack of legislation. So even for pedelecs 45 with 500 W and a possible speed of 45 km/h there is still no legislative demand for the use of a protecting helmet. 96 % of all injured cyclists in Germany had more than 0.5 ‰ alcohol in their blood, 86 % more than 1.1 ‰ and 59 % more than 1.7 ‰. Fatalities are seen in 24.2 % of cases without any collision partner. Therefore the ADFC calls for a limit of 1.1 ‰. Some virtual studies conclude that integrated sensors in bicycle helmets which would interact with sensors in cars could prevent collisions or reduce the severity of injury by stopping the cars automatically. Integrated sensors in cars with opening angles of 180° enable about 93 % of all bicyclists to be detected leading to a high rate of injury avoidance and/or mitigation. Hanging lamps reduce with 35 % significantly bicycle accidents for children, traffic education for children and special trainings for elderly bicyclists are also recommended as prevention tools. As long as helmet use for bicyclists in Germany rates only 9 % on average and legislative orders for using a helmet will not be in force in the near future, coming up campaigns seem to be necessary to be promoted by the Deutscher Verkehrssicherheitsrat as, e.g., "Helmets are cool". Also, spots in TV should be broadcasted like "The 7th sense" or "Traffic compass", which were warning car drivers many years ago of moments of danger but now they could be used to warn bicyclists of life-threatening situations in traffic.

QT variability improves risk stratification in patients with dilated cardiomyopathy.

Recently it could be demonstrated that systolic and diastolic blood pressure variability (BPV) as well as segmented Poincare plot analysis (SPPA) contribute to risk stratification in patients suffering from dilated cardiomyopathy (DCM). The aim of this study was to improve the risk stratification applying a multivariate technique including QT variability (QTV). We enrolled and significantly separated 56 low risk and 13 high risk DCM patients by nearly all applied BPV and QTV methods, but not with traditional heart rate variability analysis. The optimum set of two indices calculating the multivariate discriminate analysis (DA) included one BPV index calculated by symbolic dynamics method (DBP(Shannon)) and one index calculated from QTV (QTV(log)) achieving an area under the receiver operating characteristics curve (AUC) of 92%, sensitivity of 92.3% and specificity of 89.3%. Performing only electrocardiogram analysis, the optimum multivariate approach including indices from segmented Poincaré plot analysis and QTV still achieved a remarkable AUC of 88.3%. Increasing the number of indices for multivariate DA up to three, we achieved an AUC of 95.7%, sensitivity of 100% and specificity of 85.7% including one clinical, one BPV and one QTV index. Summarizing, we identified DCM patients with an increased risk of sudden cardiac death applying QTV analysis in a multivariate approach.

Prediction of atrial fibrillation recurrence after cardioversion-interaction analysis of cardiac autonomic regulation.

Today atrial fibrillation (AF) is the most common cardiac arrhythmia in clinical practice accounting for approximately one third of hospitalizations and accompanied with a 5 fold increased risk for ischemic stroke and a 1.5 fold increased mortality risk. The role of the cardiac regulation system in AF recurrence after electrical cardioversion (CV) is still unclear. The aim of this study was to investigate the autonomic regulation by analyzing the interaction between heart rate and blood pressure using novel methods of nonlinear interaction dynamics, namely joint symbolic dynamics (JSD) and segmented Poincaré plot analysis (SPPA). For the first time, we applied SPPA to analyze the interaction between two time series. Introducing a parameter set of two indices, one derived from JSD and one from SPPA, the linear discriminant function analysis revealed an overall accuracy of 89% (sensitivity 91.7%, specificity 86.7%) for the classification between patients with stable sinus rhythm (group SR, n = 15) and with AF recurrence (group REZ, n = 12). This study proves that the assessment of the autonomic regulation by analyzing the coupling of heart rate and systolic blood pressure provides a potential tool for the prediction of AF recurrence after CV and could aid in the adjustment of therapeutic options for patients with AF.

[Prevention of road accidents involving non-motorized traffic participants (pedestrians and cyclists) in Germany]. / Prävention von Verkehrsunfällen äußerer Verkehrsteilnehmer (Fußgänger und Fahrradfahrer) in Deutschland.

During a 1-day workshop organized by the German Society of Orthopaedics and Traumatology (DGOU) 15 German accident researchers used different approaches to improve the effectiveness of accident prevention for pedestrians and bicyclists on German roads. The main results of this analysis show: Fatal injuries of pedestrians have been significantly reduced by 82% between 1970 (n=6.056) and 2007 (n=695). Similarly, fatalities of bicyclists have been reduced during the same time period from 1,835 to 425 which amount to almost 80%. However, the total number of injured cyclists increased almost twice, i.e. from 40,531 (in 1979) to 78,579 (in 2007) a fact that needs to be analyzed in more detail. Although scientifically proven to provide protection against severe head injuries, helmets are worn less frequently by adolescents and women as compared to younger children and men. Fatalities of bicyclists might be reduced by using Dobli mirrors which allow the truck driver to see the bicyclist when turning right. Recently developed sensors are able to detect pedestrians walking closely (<2.5 m) and warn the truck driver acoustically. Bicycle lanes should be planned for one direction only, separated from the pedestrian way and large enough (2.0 m are safer than 1.6 m). Traffic education for school beginners and younger children should be repeated to be effective. Training for elderly bicyclists in cities with heavy traffic would also be reasonable. Active security systems in cars like ESP (electronic stability program), BAS (brake assist system), special light systems for curves, and night vision utilities are most effective to prevent collision with pedestrians and bicyclists. TV spots for bicyclists could help to point out dangerous situations and the proven benefits of wearing a helmet in the same way as previous campaigns, e.g."The 7th Sense" for car drivers.

Advanced Poincaré plot analysis differentiates between hypertensive pregnancy disorders.

Hypertensive pregnancy disorders affect 6% to 8% of all pregnancies and can result in severe complications for the mother and the foetus of which pre-eclampsia (PE) has the worst perinatal outcome. Several studies suggested that the autonomic nervous system plays an important role in the process of developing hypertensive pregnancy disorders, especially PE. The aim of this retrospective study was to investigate whether women with PE could be differentiated from women with various other hypertensive pregnancy disorders, by employing an enhanced Poincaré plot analysis (PPA), the segmented Poincaré plot analysis (SPPA), to their beat-to-beat interval and blood pressure signals. Sixty-nine pregnant women with hypertensive disorders (29 PE, 40 with chronic or gestational hypertension) were included. The SPPA as well as the traditional PPA found significant differences between PE and other hypertensive disorders of diastolic blood pressure (p < 0.001 versus p < 0.001) but only the SPPA method revealed significant differences (p < 0.001) also of the systolic blood pressure. Further on, linear discrimination analysis demonstrated that indices derived from SPPA are more suitable for differentiation between chronic and gestational hypertension and PE than those from traditional PPA (area under the ROC curve 0.85 versus 0.69). Therefore this procedure could contribute to the differential diagnosis of hypertensive pregnancy disorders.

Altered interactions of heart rate and blood pressure during normal and abnormal pregnancy.

The assessment of the autonomic cardiovascular regulation provides important diagnostic and prognostic information. The aim of this study was to investigate the alterations of this autonomic regulation in the progress of a normal pregnancy and in several pregnancy disorders associated with hypertension, especially pre-eclampsia, applying the method of Joint Symbolic Dynamics (JSD). The JSD reveals nonlinear interactions/ coupling between two time series.