Background In both Brugada syndrome (BS) and arrhythmogenic right ventricular cardiomyopathy (ARVC), electrical abnormalities in the right ventricular outflow tract (RVOT) are important for ...arrhythmogenesis.
Objectives The aim of this study was to compare conduction delay in the right ventricular in BS with that in ARVC using the signal-averaged electrocardiogram.
Methods Twenty patients with BS (18 men and 2 women; 55 ± 12 years old; 9 symptomatic and 11 asymptomatic) and eight patients with ARVC (six men and two women; 53 ± 16 years old) were included. We assessed the presence of late potentials (LPs) and the filtered QRS duration (fQRSd) in V2 and V5 using a high-pass filter of 40 Hz (fQRSd:40) and 100 Hz (fQRSd:100).
Results In ARVC, there was no significant difference in fQRSd:40 between V2 and V5 (158 ± 19 vs. 145 ± 17 ms, respectively): however, in BS, fQRSd:40 in V2 was significantly longer than fQRSd:40 in V5 (147 ± 15 vs. 125 ± 10 ms, P < 0.001). In ARVC, there was no significant difference between fQRSd:40 and fQRSd:100 in V2 and V5 (158 ± 19 vs. 142 ± 23 ms and 145 ± 17 vs. 132 ± 9 ms, respectively). In contrast, in BS, fQRSd:100 was significantly shorter than fQRSd:40 in V2 (110 ± 8 ms vs. 147 ± 15, P < 0.001). The relative decrease in fQRSd:100 compared with fQRSd:40 in V2 was significantly greater in BS than in ARVC.
Conclusion The dominant prolongation of the fQRSd in the right precordial lead in BS was different from the characteristics of ARVC, which may be caused by the conduction delay due to fibro-fatty replacement in RV.
The intermediate functions
I(
Q,
t) obtained from neutron spin–echo (NSE) experiments were well fitted to
I(Q,t)=I(Q,0)
exp−(Γt)
2/3
for the bicontinuous microemulsion and the lamellar phases of the ...C
12E
5/
n-octane/water system and also for the lamellar phase of the DPPC/water/CaCl
2 system. The relaxation rate
Γ increased as
Q
3. These results support the theory presented by Zilman and Granek Phys. Rev. Lett. 77 (1996) 4788. Bending modulus of the membrane ϰ was estimated in the C
12E
5/
n-octane/water system and in the DPPC/water/CaCl
2 system using their theory.
Based on Brazovskii's theory for fluctuation-induced first-order transition, we propose a dynamical model of ordered phases such as lamellar and hexagonal phases. Analysis of the suggested nonlinear ...equations shows that the system is bistable when the temperature is small enough. Close to the end point of the stable branch, the system can be transiently trapped in the intermediate ordered state.
Background: This study was performed to clarify the antiarrhythmic effects of magnesium sulfate (Mg++) in a prolonged QT interval canine model of polymorphic ventricular tachyarrhythmia (VTA).
...Methods: In six experiments in a canine model of prolonged QT by anthopleurin‐A, Mg++ was administered in boluses of 0.2 mL/kg during repetitive episodes of self‐terminating polymorphic VTA or frequent premature ventricular complexes (PVCs). The distribution of ventricular repolarization across the left ventricular(LV) wall and dispersion of transmural repolarization were analyzed before, and 30 and 120 seconds after Mg++ administration, during ventricular pacing at 100 bpm. Transmural unipolar electrograms were recorded from multipolar needle electrodes, and local activation‐recovery intervals (ARI) were measured.
Results: Mg++ rapidly eliminated self‐terminating polymorphic VTA and all isolated PVCs. During ventricular pacing at 100 bpm, Mg++ caused modest shortening of ARI at all recording sites. Since the magnitude of ARI shortening was greater at mid‐myocardial sites than at other ventricular sites, mean transmural ARI dispersion decreased from 80 ± 22 to 45 ± 18 ms within 30 seconds after Mg++ injection. However, this effect was transient, and, at 120 seconds after Mg++ administration, ARI had increased all sites and transmural ARI dispersion lengthened to 65 ± 18 ms. Besides suppression of triggered premature activity, homogenization of transmural ventricular repolarization was associated with the antiarrhythmic effects of intravenous Mg++ in this model.
Conclusion: Since these effects were transient, a continuous intravenous infusion of Mg++ is preferred to prevent recurrences of VTA.
We describe a 24-year-old woman who presented with twice previously unverified subarachnoid hemorrhages from the conus medullaris spinal arteriovenous malformation with Parkes-Weber-syndrome.
Spinal ...MRI examination is considered to be necessary for the diagnosis of Klippel-Trenaunay-Weber syndrome. For diagnosis of the spinal cord arteriovenous malformation, it is indispensable to search carefully for the presence of accompanying lesions. Transarterial glue embolization is effective for the management of the spinal vascular lesion.
Abstract
Background
Atrial fibrillation (AF) is a frequent arrhythmia in pacemaker patients and is associated with poor quality of life and increased risks of heart failure, dementia, stroke, and ...death. The MINERVA trial has shown that the combination of 3 pacing algorithms – 1) atrial antitachycardia pacing (aATP), 2) atrial preventive pacing and 3) managed ventricular pacing (MVP) - delays progression to persistent and permanent AF, compared with standard DDDR pacing mode and with MVP mode, in pacemaker patients with AF history.
Purpose
We performed a comparative non randomized evaluation to confirm the hypothesis that aATP is the main driver of persistent/permanent AF reduction independently on the effect of preventive atrial pacing.
Methods
Thirty-one Italian and Japanese Cardiology centers included consecutive dual-chamber pacemaker patients with AF history. aATP was programmed in all patients while preventive atrial pacing was not enabled. Comparison was made with all the 3 groups in MINERVA randomized trial. The main endpoint was incidence of AF longer than 7 consecutive days, as detected by device diagnostics.
Results
A total of 146 patients (73 years old, 54% male) were included and followed for a median observation period of 31 months. The 2-year incidence of AF>7 days was 12% in the aATP group, very similar to that found in the arm of the MINERVA trial with aATP enabled (13.8%, p=0.732) and significantly lower than AF incidence found in the MINERVA Control DDDR arm (25.8%, p=0.012) and in the MINERVA MVP arm (25.9%, p=0.025).
Conclusions
In a real-world population of dual-chamber pacemaker patients with AF history, use of aATP was associated with low incidence of persistent AF during follow up, highlighting that the positive results of the MINERVA trial are related to the effectiveness of aATP rather than to the effects of preventive atrial pacing.
Funding Acknowledgement
Type of funding source: None
The measurement of the direction of WIMP-induced nuclear recoils is a compelling but technologically challenging strategy to provide an unambiguous signature of the detection of Galactic dark matter. ...Most directional detectors aim to reconstruct the dark-matter-induced nuclear recoil tracks, either in gas or solid targets. The main challenge with directional detection is the need for high spatial resolution over large volumes, which puts strong requirements on the readout technologies. In this paper we review the various detector readout technologies used by directional detectors. In particular, we summarize the challenges, advantages and drawbacks of each approach, and discuss future prospects for these technologies.
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