P2576Sports in children and adolescents with congenital heart defects

Background

Age-appropriate physical activity is an important basis for healthy physical and mental development for children and adolescents with congenital heart defects (CHD)

Purpose

The main goal of this study was to learn more about the physical activity of young and adolescent CHD-patients to understand patient's needs physical activity and to improve the medical advice regarding physical activity and sports by taking the CHD-severity into account.

Methods

An online-questionnaire was developed. CHD patients registered in the German National Register for Congenital Heart Defects were invited by email/post to join the study. In total, 1,718 patients took part. 1,262 patients have finished the questionnaire and are included in the statistical analysis (average age: 11.6±3.1 years; 588 women). CHD severity: 411 patients with simple CHD, 423 with moderate CHD, 364 with complex CHD and 64 with unclassified CHD. The study participants were asked to answer questions regarding physical activity and (school) sports to evaluate their activity level and their individual needs regarding sports.

Results

We identified 831 (65.9%) patients who reported they were exercising sports for at least three days or more for 60 minutes or longer per week (simple CHD: 68.9%; moderate CHD: 64.5%; complex CHD: 63.5%; other CHD: 68.8%). Over all 47 patients (3.7%) stated that they had no regular school sports and 12 patients (1%) reported to have less than one regular sports lessen per week. Out of the 1,215 patients who reported to have regular school sports (simple CHD: 97.3%; moderate CHD: 98.1%; complex CHD: 94.5%; other CHD: 87.5%), the patients stated about how hard they usually work in a regular sports lesson as follows: “without sweating and without shortness of breath” (188 patients, 15.5%; simple CHD: 15.4%; moderate CHD: 17.1%; complex CHD: 14.8%; other CHD: 7.1%), “a little bit sweaty and a bit short of breath” (825 patients, 67.9%; simple CHD: 68.8%; moderate CHD: 65.3%; complex CHD: 68.9%; other CHD: 75%), “a lot of sweat and a lot of shortness of breath” (202 patients, 16.6%; simple CHD: 15.8%; moderate CHD: 17.6%; complex CHD: 16.3%; other CHD: 17.9%).

Conclusions

Overall, young and adolescent patients with CHD appear to be exercising sports regularly and are well integrated into school sports. Although there are slight differences between the individual degrees of CHD severity. These differences can be interpreted as minor fluctuations.

Revisited anti-inflammatory activity of matricine in vitro: Comparison with chamazulene

The proazulene matricine (1) is present in chamomile flower heads and has been proven to exhibit strong in vivo anti-inflammatory activity. In contrast to other secondary metabolites in chamomile preparations like its degradation product chamazulene (2), no plausible targets have been found to explain this activity. Therefore we revisited 1 regarding its in vitro anti-inflammatory activity in cellular and molecular studies. Using ICAM-1 as a marker for NF-κB activation, it was shown that ICAM-1 protein expression induced by TNF-α and LPS, but not by IFN-γ, was remarkably inhibited by 1 in endothelial cells (HMEC-1). Inhibition was concentration-dependent in a micromolar range (10-75 μM) and did not involve cytotoxic effects. At 75 μM expression of the adhesion molecule ICAM-1 was down to 52.7 ± 3.3% and 20.4 ± 1.8% of control in TNF-α and LPS-stimulated HMEC-1, respectively. In contrast, 2 showed no activity. Quantitative RT-PCR experiments revealed that TNF-α-induced expression of the ICAM-1 gene was also reduced by 1 in a concentration-dependent manner, reaching 32.3 ± 6.2% of control at 100 μM matricine. Additional functional assays (NF-κB promotor activity and cytoplasm to nucleus translocation) confirmed the inhibitory effect of 1 on NF-κB signaling. Despite the fact that 1 lacks an α,β-unsaturated carbonyl and is thus not able to act via a Michael reaction with electron rich SH groups of functional biological molecules, data gave strong evidence that 1 inhibits NF-κB transcriptional activity in endothelial cells by an hitherto unknown mechanism and this may contribute to its well-known anti-inflammatory activity in vivo.

Entwicklung einer Kalibrierrichtlinie für Rastersondenmikroskope (Development of a Calibration Guideline for Scanning Probe Microscopes)

Nicht nur in Forschung und Entwicklung, sondern auch zunehmend in der industriellen Fertigung kommen immer kleinere funktionelle Strukturen bis hin zu nanotechnologischen Komponenten zum Einsatz. Dadurch erlangt die Rastersondenmikroskopie auch als quantitatives Messverfahren wachsende Bedeutung und damit die Frage, wie diese Geräte zu kalibrieren sind. Dieser Bericht zielt deshalb darauf ab, den gegenwärtigen Stand der Diskussionen zu einer zukünftigen Kalibrierrichtlinie zusammenzufassen und somit ein mögliches Schema für die quantitative Charakterisierung von SPM-Messsystemen vorzustellen. Kritische Punkte werden dabei teilweise auch anhand von praktischen Beispielen diskutiert.

Design and characterization of nanostructured ultrahydrophobic coatings

Films with specific nanoroughness were designed by "virtual coating" to yield ultrahydrophobicity while the light scatter remained below an application-relevant threshold. Examples of coating experiments demonstrate the realization of predicted properties.

Optical coatings with enhanced roughness for ultrahydrophobic, low-scatter applications

Optical coatings with enhanced roughness offer promising prospects for ultrahydrophobic transparent surfaces with controlled scatter losses. Our approach links roughness characteristics with both wetting behavior and scattering. Experiments with rough oxide layers yielded surfaces with a high water contact angle.

Radiofrequency catheter ablation of inappropriate sinus tachycardia guided by activation mapping

OBJECTIVE

The purpose of this study was to evaluate the value of activation mapping for radiofrequency modification of the sinus node and the long-term success rate of the procedure in a series of patients with inappropriate sinus tachycardia.

BACKGROUND

The results of radiofrequency ablation of inappropriate sinus tachycardia have been reported in only a small number of patients.

METHODS

The subjects of this study were 29 consecutive drug-refractory patients who underwent catheter ablation of inappropriate sinus tachycardia. Target sites were selected by activation mapping during sinus tachycardia.

RESULTS

The ablation procedure was successful acutely in reducing the baseline sinus rate to <90/min and the sinus rate during isoproterenol infusion by >20% in 22 of 29 patients (76%). In 13 of 22 patients (59%) with a successful acute outcome, successive applications of radiofrequency energy at the site of earliest endocardial activation resulted in a cranial-caudal migration of earliest endocardial activation from the high lateral right atrium, along with a step-wise reduction in heart rate. In the other nine patients (41%) with a successful acute outcome, the reduction in sinus rate occurred abruptly, unaccompanied by migration of the site of earliest activation. Symptoms due to inappropriate sinus tachycardia recurred at a mean of 4.4+/-; 3 months after the ablation procedure in 6 of 22 patients (27%). After additional procedures in three patients, symptoms of inappropriate sinus tachycardia ultimately were successfully eliminated over the long-term in 19 of 29 patients (66%).

CONCLUSIONS

In conclusion, radiofrequency ablation is at best only modestly effective for managing patients with inappropriate sinus tachycardia. The two different responses of heart rate to radiofrequency ablation may reflect differences in the number and/or multicentricity of subsidiary sites of impulse generation within the sinus node and/or atrium in patients with inappropriate sinus tachycardia.

Effect of general anesthesia on the defibrillation energy requirement in patients undergoing defibrillator implantation

BACKGROUND

The effect of general anesthesia on defibrillation efficacy in humans is not known. The purpose of this study was to determine the effect of general anesthesia on the defibrillation energy requirements in patients undergoing implantation of a pectoral defibrillator.

METHODS AND RESULTS

Nineteen consecutive patients who underwent defibrillator implantation under general anesthesia were prospectively compared to 16 consecutive patients who underwent defibrillator implantation by the same physicians, using similar devices, at another hospital under conscious sedation. Pre-discharge testing was performed 1.4 +/- 1.0 days after implant using sedation in both groups. The defibrillation energy requirement was determined using the same predefined step-down protocol (15, 10, 8, 5, 3, 1 J) at the time of implantation and during pre-discharge testing. The clinical characteristics of the patients were similar between groups. There was no significant difference in the mean implant defibrillation energy requirement compared to the mean pre-discharge defibrillation energy requirement in either the general anesthesia group (8.5 +/- 4.7 vs. 8.4 +/- 3.4 J; p = 0.9) or in the conscious sedation group (9.4 +/- 3.9 vs. 9.0 +/- 3.8 J; p = 0.7).

CONCLUSIONS

When compared to conscious sedation, general anesthesia with mechanical ventilation has no significant effect on defibrillation efficacy in patients undergoing defibrillator implantation.

Effect of electrode polarity on the energy required for transthoracic atrial defibrillation

Two hundred patients with atrial fibrillation underwent transthoracic cardioversion using adhesive electrodes positioned at the apex and right infraclavicular area, and the apex electrode was randomly selected to serve as the cathode or anode. The mean defibrillation energy requirement with the cathodal configuration was significantly lower than with the anodal configuration.

Outcome of patients with nonischemic dilated cardiomyopathy and unexplained syncope treated with an implantable defibrillator

OBJECTIVES

The purpose of this study was to determine the outcome of patients with nonischemic dilated cardiomyopathy, unexplained syncope and a negative electrophysiology test who are treated with an implantable defibrillator.

BACKGROUND

Patients with nonischemic cardiomyopathy and unexplained syncope may be at high risk for sudden cardiac death, and they are sometimes treated with an implantable defibrillator.

METHODS

This study prospectively determined the outcome of 14 consecutive patients who had a nonischemic cardiomyopathy, unexplained syncope and a negative electrophysiology test and who underwent defibrillator implantation (Syncope Group). Nineteen consecutive patients with a nonischemic cardiomyopathy and a cardiac arrest who were treated with a defibrillator (Arrest Group) served as a control group.

RESULTS

Seven of 14 patients (50%) in the Syncope Group received appropriate shocks for ventricular arrhythmias during a mean follow-up of 24+/-13 months, compared with 8 of 19 patients (42%) in the Arrest Group during a mean follow-up of 45+/-40 months (p = 0.1). The mean duration from device implantation until the first appropriate shock was 32+/-7 months (95% confidence interval [CI], 18 to 45 months) in the Syncope Group compared to 72+/-12 months (95% CI, 48 to 96 months) in the Arrest Group (p = 0.1). Among patients who received appropriate shocks, the mean time from defibrillator implantation to the first appropriate shock was 10+/-14 months in the Syncope Group, compared with 48+/-47 months in the Arrest Group (p = 0.06). Recurrent syncope was always associated with ventricular tachyarrhythmias.

CONCLUSIONS

The high incidence of appropriate defibrillator shocks and the association of recurrent syncope with ventricular arrhythmias support the treatment of patients with nonischemic cardiomyopathy, unexplained syncope and a negative electrophysiology test with an implantable defibrillator.

Target temperatures of 48 degrees C versus 60 degrees C during slow pathway ablation: a randomized comparison

INTRODUCTION

The relationship between temperature at the electrode-tissue interface and the loss of AV and ventriculoatrial (VA) conduction is not established, and the optimal target temperature for the slow pathway approach to radiofrequency ablation of AV nodal reentrant tachycardia (AVNRT) is unknown. Therefore, the purpose of this study was to compare target temperatures of 48 degrees C and 60 degrees C during the slow pathway approach to ablation of AVNRT.

METHODS AND RESULTS

The study included 138 patients undergoing ablation for AVNRT. Patients undergoing slow pathway ablation using closed-loop temperature monitoring were randomly assigned to a target temperature of either 48 degrees C or 60 degrees C. The primary success rates were 76% in the patients assigned to 48 degrees C and 100% in the patients assigned to 60 degrees C (P < 0.01). The ablation procedure duration (33 +/- 31 min vs 26 +/- 28 min; P = 0.2), fluoroscopic time (25 +/- 15 min vs 24 +/- 16 min; P = 0.5), and mean number of applications (9.3 +/- 6.5 vs 7.8 +/- 8.1; P = 0.3) were similar in patients assigned to 48 degrees and 60 degrees C, respectively. The mean temperature (46.1 degrees +/- 24.8 degrees C vs 48.7 +/- 3.2 degrees C; P < 0.01), the temperature associated with junctional ectopy (48.1 degrees +/- 2.0 degrees C vs 53.5 degrees +/- 3.5 degrees C, P < 0.0001), and the frequency of VA block during junctional ectopy (24.6% vs 37.2%; P < 0.0001) were less in the patients assigned to 48 degrees C compared to 60 degrees C. The frequency of transient or permanent AV block was similar in each group (2.8% vs 3.6%; P = 0.2). In the 60 degrees C group, only 12% of applications achieved an electrode temperature of 60 degrees C. During follow-up of 9.9 +/- 4.2 months, there was one recurrence of AVNRT in the 48 degrees C group and none in the 60 degrees C group.

CONCLUSIONS

Compared to 48 degrees C, a target temperature of 60 degrees C during radiofrequency slow pathway ablation is associated with a higher primary success rate and a higher incidence of VA block during junctional ectopy induced by the radiofrequency energy. AV block is not more common with the higher target temperature, but only if VA conduction is aggressively monitored during applications of radiofrequency energy.

Relationship between shock energy and postdefibrillation ventricular arrhythmias in patients with implantable defibrillators

BACKGROUND

The relationship between postdefibrillation ventricular arrhythmias and shock strength is poorly understood in patients with implantable defibrillators. The purpose of this study was to characterize the relationship between postdefibrillation ventricular arrhythmias and shock strength.

METHODS AND RESULTS

Forty-three patients with an implanted defibrillator underwent six separate inductions of ventricular fibrillation (VF) after a step-down defibrillation energy requirement (7.3 +/- 4.6 J) was determined. For each of the first three inductions of VF, the first two shocks were low energy and equal to approximately 75% of the defibrillation energy requirement (5.4 +/- 3.3 J), or to the defibrillation energy requirement plus 10 J (17.5 +/- 4.3 J). After the first two shocks, subsequent shocks were programmed to the maximum available energy (29.0 +/- 2.5 J). The alternate technique was used for the subsequent three inductions of VF. Postdefibrillation ventricular arrhythmias were noted. Postdefibrillation ventricular arrhythmias with a cycle length < or = 300 msec were more frequent after a low-energy shock (19%), than after a high-energy shock (1.5%; P = 0.005). Postdefibrillation ventricular arrhythmias with a cycle length < or = 300 msec were more frequent after a high-energy shock (32%), than after a low-energy shock (7.1%; P = 0.002). A relationship between the cycle length of the postdefibrillation ventricular arrhythmias and the absolute defibrillation energy was observed (P < 0.001; r = 0.6), and ventricular arrhythmias with a cycle length > 300 msec were uncommon after shocks < or = 10 J (P = 0.001). The characteristics of ventricular arrhythmias after maximum-energy shocks were similar to those that occurred after high-energy shocks.

CONCLUSIONS

Postdefibrillation ventricular arrhythmias with a cycle length < or = 300 msec are more common after shocks of strength associated with a low probability of successful defibrillation. Postdefibrillation ventricular arrhythmias with a cycle length of > 300 msec are more common after high- and maximum-energy shocks, and are directly related to the absolute defibrillation energy.

A technique for the rapid diagnosis of atrial tachycardia in the electrophysiology laboratory

OBJECTIVE

The purpose of this study was to determine if the atrial response upon cessation of ventricular pacing associated with 1:1 ventriculoatrial conduction during paroxysmal supraventricular tachycardia is a useful diagnostic maneuver in the electrophysiology laboratory.

BACKGROUND

Despite various maneuvers, it can be difficult to differentiate atrial tachycardia from other forms of paroxysmal supraventricular tachycardia.

METHODS

The response upon cessation of ventricular pacing associated with 1:1 ventriculoatrial conduction was studied during four types of tachycardia: 1) atrioventricular nodal reentry (n = 102), 2) orthodromic reciprocating tachycardia (n = 43), 3) atrial tachycardia (n = 19) and 4) atrial tachycardia simulated by demand atrial pacing in patients with inducible atrioventricular nodal reentry or orthodromic reciprocating tachycardia (n = 32). The electrogram sequence upon cessation of ventricular pacing was, categorized as "atrial-ventricular" (A-V) or "atrial-atrial-ventricular" (A-A-V).

RESULTS

The A-V response was observed in all cases of atrioventricular nodal reentrant and orthodromic reciprocating tachycardia. In contrast, the A-A-V response was observed in all cases of atrial tachycardia and simulated atrial tachycardia, even in the presence of dual atrioventricular nodal pathways or a concealed accessory atrioventricular pathway.

CONCLUSIONS

In conclusion, an A-A-V response upon cessation of ventricular pacing associated with 1:1 ventriculoatrial conduction is highly sensitive and specific for the identification of atrial tachycardia in the electrophysiology laboratory.

Long-term evaluation of the ventricular defibrillation energy requirement

INTRODUCTION

Defibrillation energy requirements in patients with nonthoracotomy defibrillators may increase within several months after implantation. However, the stability of the defibrillation energy requirement beyond 1 year has not been reported. The purpose of this study was to characterize the defibrillation energy requirement during 2 years of clinical follow-up.

METHODS AND RESULTS

Thirty-one consecutive patients with a biphasic nonthoracotomy defibrillation system underwent defibrillation energy requirement testing using a step-down technique (20, 15, 12, 10, 8, 6, 5, 4, 3, 2, and 1 J) during defibrillator implantation, and then 24 hours, 2 months, 1 year, and 2 years after implantation. The mean defibrillation energy requirement during these evaluations was 10.9+/-5.5 J, 12.3+/-7.3 J, 11.7+/-5.6 J, 10.2+/-4.0 J, and 11.7+/-7.4 J, respectively (P = 0.4). The defibrillation energy requirement was noted to have increased by 10 J or more after 2 years of follow-up in five patients. In one of these patients, the defibrillation energy requirement was no longer associated with an adequate safety margin, necessitating revision of the defibrillation system. There were no identifiable clinical characteristics that distinguished patients who did and did not develop a 10-J or more increase in the defibrillation energy requirement.

CONCLUSION

The mean defibrillation energy requirement does not change significantly after 2 years of biphasic nonthoracotomy defibrillator system implantation. However, approximately 15% of patients develop a 10-J or greater elevation in the defibrillation energy requirement, and 3% may require a defibrillation system revision. Therefore, a yearly evaluation of the defibrillation energy requirement may be appropriate.

Differential effect of adenosine on anterograde and retrograde fast pathway conduction in patients with atrioventricular nodal reentrant tachycardia

INTRODUCTION

Several studies have shown that the fast pathway is more responsive to adenosine than the slow pathway in patients with AV nodal reentrant tachycardia. Little information is available regarding the effect of adenosine on anterograde and retrograde fast pathway conduction.

METHODS AND RESULTS

The effects of adenosine on anterograde and retrograde fast pathway conduction were evaluated in 116 patients (mean age 47 +/- 16 years) with typical AV nodal reentrant tachycardia. Each patient received 12 mg of adenosine during ventricular pacing at a cycle length 20 msec longer than the fast pathway VA block cycle length and during sinus rhythm or atrial pacing at 20 msec longer than the fast pathway AV block cycle length. Anterograde block occurred in 98% of patients compared with retrograde fast pathway block in 62% of patients (P < 0.001). Unresponsiveness of the retrograde fast pathway to adenosine was associated with a shorter AV block cycle length (374 +/- 78 vs 333 +/- 74 msec, P < 0.01), a shorter VA block cycle length (383 +/- 121 vs 307 +/- 49 msec, P < 0.001), and a shorter VA interval during tachycardia (53 +/- 23 vs 41 +/- 17 msec, P < 0.01).

CONCLUSION

Although anterograde fast pathway conduction is almost always blocked by 12 mg of adenosine, retrograde fast pathway conduction is not blocked by adenosine in 38% of patients with typical AV nodal reentrant tachycardia. This indicates that the anterograde and retrograde fast pathways may be anatomically and/or functionally distinct. Unresponsiveness of VA conduction to adenosine is not a reliable indicator of an accessory pathway.

Function of gene 49 of bacteriophage T4 III. Isolation of Holliday structures from very fast-sedimenting DNA

Branched DNA molecules were identified in ClaI digests of cytosine containing very fast-sedimenting DNA (VFS-DNACYT) which was isolated from Escherichia coli infected with the multiple mutant 49-GT7 of phage T4. In about 10% of randomly picked ClaI fragments branches with three arms (Y-structures) as well as four arms (Holliday structures) were seen in the electron microscope. Branched structures were absent from ClaI digests after treatment with purified endonuclease VII (gp49) in vitro.

[Alopecia in meralgia paraesthetica]

Two patients are described who had a lesion in the lateral cutaneous nerves of the thigh, both of which were verified by anamnestic, clinical and electrophysiological data. Both showed alopecia in the region supplied by the nerve. A biopsy performed on one patient showed atrophy of the epidermis and hair follicles. It is pointed out that this kind of trophic disturbance, which is very seldom described in literature on meralgia paraesthetica, may possibly be found more often in long-standing cases of this disease.

In vitro formation of different tubulin polymers from purified tubulin of Ehrlich ascites tumor cells

Preparations of cycled tubulin from Ehrlich ascites tumor cells contain several accessory proteins; once or twice cycled microtubule preparations are usually composed of fibers 10 nm in diameter, but lack vimentin. Highly purified tubulin consists of alpha- and beta-tubulin and a minor component which was identified by peptide mapping as a second beta-chain. This pure tubulin is able to form in vitro at low concentrations (1 mg protein/ml) fibers of about 10 nm width, and at higher concentrations (3.5 mg protein/ml) normal microtubules.