Atrial remodeling, autonomic tone, and lifetime training hours in nonelite athletes

Endurance athletes have an increased risk of developing atrial fibrillation (AF) at 40 to 50 years of age. Signal-averaged P-wave analysis has been used for identifying patients at risk for AF. We evaluated the impact of lifetime training hours on signal-averaged P-wave duration and modifying factors. Nonelite men athletes scheduled to participate in the 2010 Grand Prix of Bern, a 10-mile race, were invited. Four hundred ninety-two marathon and nonmarathon runners applied for participation, 70 were randomly selected, and 60 entered the final analysis. Subjects were stratified according to their lifetime training hours (average endurance and strength training hours per week × 52 × training years) in low (<1,500 hours), medium (1,500 to 4,500 hours), and high (>4,500 hours) training groups. Mean age was 42 ± 7 years. From low to high training groups signal-averaged P-wave duration increased from 131 ± 6 to 142 ± 13 ms (p = 0.026), and left atrial volume increased from 24.8 ± 4.6 to 33.1 ± 6.2 ml/m(2) (p = 0.001). Parasympathetic tone expressed as root of the mean squared differences of successive normal-to-normal intervals increased from 34 ± 13 to 47 ± 16 ms (p = 0.002), and premature atrial contractions increased from 6.1 ± 7.4 to 10.8 ± 7.7 per 24 hours (p = 0.026). Left ventricular mass increased from 100.7 ± 9.0 to 117.1 ± 18.2 g/m(2) (p = 0.002). Left ventricular systolic and diastolic function and blood pressure at rest were normal in all athletes and showed no differences among training groups. Four athletes (6.7%) had a history of paroxysmal AF, as did 1 athlete in the medium training group and 3 athletes in the high training group (p = 0.252). In conclusion, in nonelite men athletes lifetime training hours are associated with prolongation of signal-averaged P-wave duration and an increase in left atrial volume. The altered left atrial substrate may facilitate occurrence of AF. Increased vagal tone and atrial ectopy may serve as modifying and triggering factors.

Active regulation of cerebral venous tone: simultaneous arterial and venous transcranial Doppler sonography during a Valsalva manoeuvre

The aim of this study was to analyse the cerebral venous outflow in relation to the arterial inflow during a Valsalva manoeuvre (VM). In 19 healthy volunteers (mean age 24.1 +/- 2.6 years), the middle cerebral artery (MCA) and the straight sinus (SRS) were insonated by transcranial Doppler sonography. Simultaneously the arterial blood pressure was recorded using a photoplethysmographic method. Two VM of 10 s length were performed per participant. Tracings of the variables were then transformed to equidistantly re-sampled data. Phases of the VM were analysed regarding the increase of the flow velocities and the latency to the peak. The typical four phases of the VM were also found in the SRS signal. The relative flow velocity (FV) increase was significantly higher in the SRS than in the MCA for all phases, particularly that of phase IV (p < 0.01). Comparison of the time latency of the VM phases of the MCA and SRS only showed a significant difference for phase I (p < 0.01). In particular, there was no significant difference for phase IV (15.8 +/- 0.29 vs. 16.0 +/- 0.28 s). Alterations in venous outflow in phase I are best explained by a cross-sectional change of the lumen of the SRS, while phases II and III are compatible with a Starling resistor. However, the significantly lager venous than the arterial overshoot in phase IV may be explained by the active regulation of the venous tone.

Gender differences of atrial and ventricular remodeling and autonomic tone in nonelite athletes

Veteran endurance athletes have an increased risk of developing atrial fibrillation (AF), with a striking male predominance. We hypothesized that male athletes were more prone to atrial and ventricular remodeling and investigated the signal-averaged P wave and factors that promote the occurrence of AF. Nonelite athletes scheduled to participate in the 2010 Grand Prix of Bern, a 10-mile race, were invited. Of the 873 marathon and nonmarathon runners who were willing to participate, 68 female and 70 male athletes were randomly selected. The runners with cardiovascular disease or elevated blood pressure (>140/90 mm Hg) were excluded. Thus, 121 athletes were entered into the final analysis. Their mean age was 42 ± 7 years. No gender differences were found for age, lifetime training hours, or race time. The male athletes had a significantly longer signal-averaged P-wave duration (136 ± 12 vs 122 ± 10 ms; p <0.001). The left atrial volume was larger in the male athletes (56 ± 13 vs 49 ± 10 ml; p = 0.001), while left atrial volume index showed no differences (29 ± 7 vs 30 ± 6 ml/m²; p = 0.332). In male athletes, the left ventricular mass index (107 ± 17 vs 86 ± 16 g/m²; p <0.001) and relative wall thickness (0.44 ± 0.06 vs 0.41 ± 0.07; p = 0.004) were greater. No differences were found in the left ventricular ejection fraction (63 ± 4% vs 66 ± 6%; p = 0.112) and mitral annular tissue Doppler e' velocity (10.9 ± 1.5 vs 10.6 ± 1.5 cm/s; p = 0.187). However, the tissue Doppler a' velocity was higher (8.7 ± 1.2 vs 7.6 ± 1.3 cm/s; p < 0.001) in the male athletes. Male athletes had a higher systolic blood pressure at rest (123 ± 9 vs 110 ± 11 mm Hg; p < 0.001) and at peak exercise (180 ± 15 vs 169 ± 19 mm Hg; p = 0.001). In the frequency domain analysis of heart rate variability, the sympatho-vagal balance, represented by the low/high-frequency power ratio, was significantly greater in male athletes (5.8 ± 2.8 vs 3.9 ± 1.9; p < 0.001). Four athletes (3.3%) had at least one documented episode of paroxysmal AF, all were men (p = 0.042). In conclusion, for a comparable amount of training and performance, male athletes showed a more pronounced atrial remodeling, a concentric type of ventricular remodeling, and an altered diastolic function. A higher blood pressure at rest and during exercise and a higher sympathetic tone might be causal. The altered left atrial substrate might facilitate the occurrence of AF.

Cerebral correlates of muscle tone fluctuations in restless legs syndrome: A pilot study with combined functional magnetic resonance imaging and anterior tibial muscle electromyography

BACKGROUND: The pathology of restless legs syndrome (RLS) is still not understood. To investigate the pathomechanism of the disorder further we recorded a surface electromyogram (EMG) of the anterior tibial muscle during functional magnetic resonance imaging (fMRI) in patients with idiopathic RLS. METHODS: Seven subjects with moderate to severe RLS were investigated in the present pilot study. Patients were lying supine in the scanner for over 50min and were instructed not to move voluntarily. Sensory leg discomfort (SLD) was evaluated on a 10-point Likert scale. For brain image analysis, an algorithm for the calculation of tonic EMG values was developed. RESULTS: We found a negative correlation of tonic EMG and SLD (p <0.01). This finding provides evidence for the clinical experience that RLS-related subjective leg discomfort increases during muscle relaxation at rest. In the fMRI analysis, the tonic EMG was associated with activation in motor and somatosensory pathways and also in some regions that are not primarily related to motor or somatosensory functions. CONCLUSIONS: By using a newly developed algorithm for the investigation of muscle tone-related changes in cerebral activity, we identified structures that are potentially involved in RLS pathology. Our method, with some modification, may also be suitable for the investigation of phasic muscle activity that occurs during periodic leg movements.

Bone-anchored Hearing Aids: correlation between pure-tone thresholds and outcome in three user groups

OBJECTIVE: To investigate correlations between preoperative hearing thresholds and postoperative aided thresholds and speech understanding of users of Bone-anchored Hearing Aids (BAHA). Such correlations may be useful to estimate the postoperative outcome with BAHA from preoperative data. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS:: Ninety-two adult unilaterally implanted BAHA users in 3 groups: (A) 24 subjects with a unilateral conductive hearing loss, (B) 38 subjects with a bilateral conductive hearing loss, and (C) 30 subjects with single-sided deafness. INTERVENTIONS: Preoperative air-conduction and bone-conduction thresholds and 3-month postoperative aided and unaided sound-field thresholds as well as speech understanding using German 2-digit numbers and monosyllabic words were measured and analyzed. MAIN OUTCOME MEASURES: Correlation between preoperative air-conduction and bone-conduction thresholds of the better and of the poorer ear and postoperative aided thresholds as well as correlations between gain in sound-field threshold and gain in speech understanding. RESULTS: Aided postoperative sound-field thresholds correlate best with BC threshold of the better ear (correlation coefficients, r2 = 0.237 to 0.419, p = 0.0006 to 0.0064, depending on the group of subjects). Improvements in sound-field threshold correspond to improvements in speech understanding. CONCLUSION: When estimating expected postoperative aided sound-field thresholds of BAHA users from preoperative hearing thresholds, the BC threshold of the better ear should be used. For the patient groups considered, speech understanding in quiet can be estimated from the improvement in sound-field thresholds.

Apatani phonology and lexicon, with a special focus on tone

Despite being one of the most extensively researched of Eastern Himalayan languages, the basic morphological and phonological-prosodic properties of Apatani (Tibeto-Burman > Tani > Western) have not yet been adequately described. This article attempts such a description, focusing especially on interactions between segmental-syllabic phonology and tone in Apatani. We highlight three features in particular – vowel length, nasality and a glottal stop – which contribute to contrastively-weighted syllables in Apatani, which are consistently under-represented in previous descriptions of Apatani, and in absence of which tone in Apatani cannot be effectively analysed. We conclude that Apatani has two “underlying”, lexically-specified tone categories H and L, whose interaction with word structure and syllable weight produce a maximum of three “surface” pitch contours – level, falling and rising – on disyllabic phonological words. Two appendices provide a set of diagnostic procedures for the discovery and description of Apatani tone categories, as well as an Apatani lexicon of approximately one thousand entries.

Oxidative Stress in Hypobaric Hypoxia and Influence on Vessel-Tone Modifying Mediators

Increased pulmonary artery pressure is a well-known phenomenon of hypoxia and is seen in patients with chronic pulmonary diseases, and also in mountaineers on high altitude expedition. Different mediators are known to regulate pulmonary artery vessel tone. However, exact mechanisms are not fully understood and a multimodal process consisting of a whole panel of mediators is supposed to cause pulmonary artery vasoconstriction. We hypothesized that increased hypoxemia is associated with an increase in vasoconstrictive mediators and decrease of vasodilatators leading to a vasoconstrictive net effect. Furthermore, we suggested oxidative stress being partly involved in changement of these parameters. Oxygen saturation (Sao2) and clinical parameters were assessed in 34 volunteers before and during a Swiss research expedition to Mount Muztagh Ata (7549 m) in Western China. Blood samples were taken at four different sites up to an altitude of 6865 m. A mass spectrometry-based targeted metabolomic platform was used to detect multiple parameters, and revealed functional impairment of enzymes that require oxidation-sensitive cofactors. Specifically, the tetrahydrobiopterin (BH4)-dependent enzyme nitric oxide synthase (NOS) showed significantly lower activities (citrulline-to-arginine ratio decreased from baseline median 0.21 to 0.14 at 6265 m), indicating lower NO availability resulting in less vasodilatative activity. Correspondingly, an increase in systemic oxidative stress was found with a significant increase of the percentage of methionine sulfoxide from a median 6% under normoxic condition to a median level of 30% (p<0.001) in camp 1 at 5533 m. Furthermore, significant increase in vasoconstrictive mediators (e.g., tryptophan, serotonin, and peroxidation-sensitive lipids) were found. During ascent up to 6865 m, significant altitude-dependent changes in multiple vessel-tone modifying mediators with excess in vasoconstrictive metabolites could be demonstrated. These changes, as well as highly significant increase in systemic oxidative stress, may be predictive for increase in acute mountain sickness score and changes in Sao2.

Sex differences in heart rate variability: a longitudinal study in international elite cross-country skiers

PURPOSE: Exercise-related sudden cardiac deaths (SCD) occur with a striking male predominance. A higher sympathetic tone in men has been suggested as risk factor for SCD. Elite athletes have the highest risk for exercise-related SCD. We aimed to analyze the autonomic nervous system of elite cross-country skiers from Norway, Russia and Switzerland in supine position and after orthostatic challenge in various training periods (TP). METHOD: Measurements of heart rate variability (HRV) were performed on a weekly basis over 1 year using an orthostatic challenge test with controlled breathing. Main outcome parameters were the high-frequency power in supine position (HFsupine) as marker of cardiac parasympathetic activity and the low-frequency/high-frequency power ratio after orthostatic challenge (LF/HFstand) as marker of cardiac sympathetic activation. Training intensity and duration were recorded daily and expressed as training strain. The training year was divided into three TPs. An average of weekly HRV measurements was calculated for each TP. RESULT: Female (n = 19, VO2max 62.0 +/- 4.6 ml kg(-1) min(-1), age 25.8 +/- 4.3 years) and male (n = 16, VO2max 74.3 +/- 6.3 ml kg(-1) min(-1), age 24.4 +/- 4.2 years) athletes were included. Training strain was comparable between sexes (all p > 0.05) and changed between TPs (all p < 0.05) while no HRV parameters changed over time. There were no sex differences in HFsupine while the LF/HFstand was significantly higher in male athletes in all TPs. CONCLUSION: For a comparable amount of training, male athletes showed constantly higher markers of sympathetic activity after a provocation maneuver. This may explain part of the male predominance in sports-related SCD.

Treatment of optic neuritis with erythropoietin (TONE): a randomised, double-blind, placebo-controlled trial-study protocol.

INTRODUCTION Optic neuritis leads to degeneration of retinal ganglion cells whose axons form the optic nerve. The standard treatment is a methylprednisolone pulse therapy. This treatment slightly shortens the time of recovery but does not prevent neurodegeneration and persistent visual impairment. In a phase II trial performed in preparation of this study, we have shown that erythropoietin protects global retinal nerve fibre layer thickness (RNFLT-G) in acute optic neuritis; however, the preparatory trial was not powered to show effects on visual function. METHODS AND ANALYSIS Treatment of Optic Neuritis with Erythropoietin (TONE) is a national, randomised, double-blind, placebo-controlled, multicentre trial with two parallel arms. The primary objective is to determine the efficacy of erythropoietin compared to placebo given add-on to methylprednisolone as assessed by measurements of RNFLT-G and low-contrast visual acuity in the affected eye 6 months after randomisation. Inclusion criteria are a first episode of optic neuritis with decreased visual acuity to ≤0.5 (decimal system) and an onset of symptoms within 10 days prior to inclusion. The most important exclusion criteria are history of optic neuritis or multiple sclerosis or any ocular disease (affected or non-affected eye), significant hyperopia, myopia or astigmatism, elevated blood pressure, thrombotic events or malignancy. After randomisation, patients either receive 33 000 international units human recombinant erythropoietin intravenously for 3 consecutive days or placebo (0.9% saline) administered intravenously. With an estimated power of 80%, the calculated sample size is 100 patients. The trial started in September 2014 with a planned recruitment period of 30 months. ETHICS AND DISSEMINATION TONE has been approved by the Central Ethics Commission in Freiburg (194/14) and the German Federal Institute for Drugs and Medical Devices (61-3910-4039831). It complies with the Declaration of Helsinki, local laws and ICH-GCP. TRIAL REGISTRATION NUMBER NCT01962571.

Non-organic hearing loss: new and confirmed findings

Although non-organic hearing losses are relatively rare, it is important to identify suspicious findings early to be able to administer specific tests, such as objective measurements and specific counseling. In this retrospective study, we searched for findings that were specific ti or typical for non-organic hearing losses. Patient records from a 6 year period (2003-2008) from the University ENT Department of Bern, Switzerland, were reviewed. In this period, 40 subjects were diagnosed with a non-organic hearing loss (22 children, ages 7-16, mean 10.6 years; 18 adults, ages 19-57, mean 39.7 years; 25 females and 15 males). Pure tone audiograms in children and adults showed predominantly sensorineural and frequency-independent hearing losses, mostly in the range of 40-60 dB. In all cases, objective measurements (otoacoustic emissions and/or auditory-evoked potentials) indicated normal or substantially better hearing thresholds than those found in pure tone audiometry. In nine subjects (22.5%; 2 children, 7 adults), hearing aids had been fitted before the first presentation at our center. Six children (27%) had a history of middle ear problems with a transient hearing loss and 11 (50%) knew a person with a hearing loss. Two new and hitherto unreported findings emerged from the analysis: it was observed that a small air-bone gap of 5-20 dB was typical for non-organic hearing losses and that speech audiometry might show considerably poorer results than expected from pure tone audiometry.

Consensus statement of the European Heart Rhythm Association: updated recommendations for driving by patients with implantable cardioverter defibrillators

Patients with an implantable cardioverter defibrillator (ICD) have an ongoing risk of sudden incapacitation that might cause harm to others while driving a car. Driving restrictions vary across different countries in Europe. The most recent recommendations for driving of ICD patients in Europe were published in 1997 and focused mainly on patients implanted for secondary prevention. In recent years there has been a vast increase in the number of patients with an ICD and in the percentage of patients implanted for primary prevention. The EHRA task force on ICD and driving was formed to reassess the risk of driving for ICD patients based on the literature available. The recommendations are summarized in the following table and are further explained in the document, (Table see text). Driving restrictions are perceived as difficult for patients and their families, and have an immediate consequence for their lifestyle. To increase the adherence to the driving restrictions, adequate discharge of education and follow-up of patients and family are pivotal. The task force members hope this document may serve as an instrument for European and national regulatory authorities to formulate uniform driving regulations.

Early repolarization, left ventricular diastolic function, and left atrial size in professional soccer players

Recent data have suggested a relation among long-term endurance sport practice, left atrial remodeling, and atrial fibrillation. We investigated the influence of an increased vagal tone, represented by the early repolarization (ER) pattern, on diastolic function and left atrial size in professional soccer players. Fifty-four consecutive athletes underwent electrocardiography, echocardiography, and exercise testing as part of their preparticipation screening. Athletes were divided into 2 groups according to presence or absence of an ER pattern, defined as a ST-segment elevation at the J-point (STE) > or =0.1 mm in 2 leads. For linear comparisons average STE was calculated. Mean age was 24 +/- 4 years. Twenty-five athletes (46%) showed an ER pattern. Athletes with an ER pattern had a significant lower heart rate (54 +/- 9 vs 62 +/- 11 beats/min, p = 0.024), an increased E/e' ratio (6.1 +/- 1.2 vs 5.1 +/- 1.0, p = 0.002), and larger volumes of the left atrium (25.6 +/- 7.3 vs 21.8 +/- 5.0 ml/m(2), p = 0.031) compared to athletes without an ER pattern. There were no significant differences concerning maximum workload, left ventricular dimensions, and systolic function. Univariate regression analysis revealed significant correlations among age, STE, and left atrial volume. In a stepwise multivariate regression analysis age, STE and e' contributed independently to left atrial size (r = 0.659, p <0.001). In conclusion, athletes with an ER pattern had an increased E/e' ratio, reflecting a higher left atrial filling pressure, contributing to left atrial remodeling over time.