445 research outputs found
Le point sur l'ergométrie en 2012 dans le diagnostic de la maladie coronarienne.
Background In patients presenting with acute cardiac
symptoms, abnormal ECG and raised troponin,
myocarditis may be suspected after normal angiography.
Aims To analyse cardiac magnetic resonance (CMR)
findings in patients with a provisional diagnosis of acute
coronary syndrome (ACS) in whom acute myocarditis
was subsequently considered more likely.
Methods and results 79 patients referred for CMR
following an admission with presumed ACS and raised
serum troponin in whom no culprit lesion was detected
were studied. 13% had unrecognised myocardial
infarction and 6% takotsubo cardiomyopathy. The
remainder (81%) were diagnosed with myocarditis.
Mean age was 45615 years and 70% were male. Left
ventricular ejection fraction (EF) was 58610%;
myocardial oedema was detected in 58%. A myocarditic
pattern of late gadolinium enhancement (LGE) was
detected in 92%. Abnormalities were detected more
frequently in scans performed within 2 weeks of
symptom onset: oedema in 81% vs 11% (p<0.0005),
and LGE in 100% vs 76% (p<0.005). In 20 patients with
both an acute (<2 weeks) and convalescent scan
(>3 weeks), oedema decreased from 84% to 39%
(p<0.01) and LGE from 5.6 to 3.0 segments (p¼0.005).
Three patients presented with sustained ventricular
tachycardia, another died suddenly 4 days after
admission and one resuscitated 7 weeks following
presentation. All 5 patients had preserved EF.
Conclusions Our study emphasises the importance of
access to CMR for heart attack centres. If myocarditis is
suspected, CMR scanning should be performed within
14 days. Myocarditis should not be regarded as benign,
even when EF is preserved
Catheter entrapment in a pulmonary vein: a unique complication of pulmonary vein isolation.
Ablation strategies for the treatment of atrial fibrillation (AF) are associated with several potential complications. During electro-anatomic mapping of the left atrium (LA) before ablation, the ablation catheter was entrapped in the right inferior pulmonary vein (RIPV). After multiple unsuccessful gentle tractions, stronger maneuvers with rotation of the catheter slowly allowed its retrieval. Examination of the catheter showed a thin, translucent membrane covering its tip, suggesting complete stripping of a vein branch. Occlusion of the superior branch of the RIPV was confirmed by LA angiogram. During the following days, no pericardial effusion was noted, but the patient complained of light chest pain and mild hemoptysis, spontaneously resolving within 48 h. This case shows that catheter entrapment and mechanical disruption of a PV branch can be a rare potential complication of AF ablation. In this case, the outcome was spontaneously favorable and symptoms only included transient mild hemoptysis
Temperature dependence of the excitonic insulator phase model in 1T-TiSe2
Recently, detailed calculations of the excitonic insulator phase model
adapted to the case of 1\textit{T}-TiSe have been presented. Through the
spectral function theoretical photoemission intensity maps can be generated
which are in very good agreement with experiment [Phys. Rev. Lett. {\bf 99},
(2007) 146403]. In this model, excitons condensate in a BCS-like manner and
give rise to a charge density wave, characterized by an order parameter. Here,
we assume an analytical form of the order parameter, allowing to perform
temperature dependent calculations. The influence of this order parameter on
the electronic spectral function, to be observed in photoemission spectra, is
discussed. The resulting chemical potential shift and an estimation of the
resistivity are also shown.Comment: 4 pages, 3 figures, paper submitted at the Strongly Correlated
Electron System conference, Brazil, 200
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Exciton condensation driving the periodic lattice distortion of 1T-TiSe2
We address the lattice instability of 1T-TiSe2 in the framework of the
exciton condensate phase. We show that, at low temperature, condensed excitons
influence the lattice through electron-phonon interaction. It is found that at
zero temperature, in the exciton condensate phase of 1T-TiSe2, this exciton
condensate exerts a force on the lattice generating ionic displacements
comparable in amplitude to what is measured in experiment. This is thus the
first quantitative estimation of the amplitude of the periodic lattice
distortion observed in 1T-TiSe2 as a consequence of the exciton condensate
phase.Comment: 5 pages, 3 figures and 1 tabl
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