Der Akute Herzinfarkt bei Frauen : Eine Rarität oder häufig übersehen?

Bundesweit erleiden etwa 300.000 Menschen pro Jahr einen Herzinfarkt durch einen plötzlichen und kompletten Verschluß eines Herzkranzgefäßes. Prähospitale (20-30%) und hospitale (10-20%) Sterblichkeit des akuten Herzinfarktes sind hoch. Der Verlauf des Herzinfarktes ist bei Frauen, insbesondere bei jungen Frauen, komplikationsträchtiger als bei Männern. Dies gilt, wenn keine spezifische gefäßwiedereröffnende Therapie eingeleitet wird. Die Ursachen für die Übersterblichkeit der Frauen sind vielfältig: verspätete Krankenhausaufnahme, höheres Lebensalter zum Infarktzeitpunkt, bedeutsamere Begleiterkrankungen und der zögerliche Einsatz gefäßwiedereröffnender Therapieformen. Bei früher und konsequenter kathetergestützter Gefäßrekanalisation kann die geschlechtsspezifische Sterblichkeit bei Frauen aller Altersstufen aber weitgehend beseitigt werden

Detection of myocardial injury during transvenous implantation of automatic cardioverter-defibrillators

AbstractOBJECTIVESThe present study was designed to assess the extent of myocardial injury in patients undergoing transvenous implantation of an automatic implantable cardioverter-defibrillator (ICD) using cardiac troponin I (cTNI), which is a highly specific marker of structural cardiac injury.BACKGROUNDDuring ICD implantation, repetitive induction and termination of ventricular fibrillation (VF) via endocardial direct current shocks is required to demonstrate the correct function of the device. Transthoracic electrical shocks can cause myocardial cell injury.METHODSMeasurements of total creatine kinase (CK), CK-MB, myoglobin, cardiac troponin T (cTNT) and cTNI were obtained before and after ICD implantation in 49 consecutive patients. Blood samples were drawn before and 2, 4, 8, and 24 h after implantation.RESULTSElevations of CK, CK-MB, myoglobin, cTNT and cTNI above cut-off level were found in 25%, 6%, 76%, 37% and 14% of patients, respectively, with peak cTNI concentrations ranging from 1.7 to 5.5 ng/ml. Cumulative defibrillation energy (DFE), mean DFE, cumulative VF time, number of shocks as well as prior myocardial infarction (MI) were found to be significantly related to a rise of cTNI. Mean DFE ≥ 18 J and a recent MI were identified as strong risk factors for cTNI rise.CONCLUSIONSDuring transvenous ICD implantation myocardial injury as assessed by cTNI rise occurs in about 14% of the patients. Peak cTNI concentrations are only minimally elevated reflecting subtle myocardial cell damage. Patients with a recent MI and a mean DFE ≥ 18 J seem to be prone to cTNI rise

Ventricular arrhythmias initiated by programmed stimulation in four groups of patients with healed myocardial infarction

Programmed electrical stimulation of the heart was prospectively used in 160 patients with healed myocardial infarction to study the incidence and characteristics of ventricular arrhythmias induced. Thirty-five patients had neither documented nor suspected ventricular arrhythmias (Group A); 37 patients had documented nonsus-tained ventricular tachycardia (Group B); 31 patients had been resuscitated from ventricular fibrillation (Group C); and 57 patients had documented sustained mono-morphic ventricular tachycardia (Group D). No electrophysiologic differences were found between patients in Group A and Group B, but patients in both groups differed significantly from patients in Group C and Group D. In the last two groups, sustained monomorphic ventricular tachycardia was more frequently induced, the cycle length of the induced ventricular tachycardia was slower and a lesser number of premature stimuli was required for induction. No differences were found in the incidence, rate or mode of induction of nonsustained monomorphic ventricular tachycardia, but nonsustained polymorphic ventricular tachycardia and ventricular fibrillation were more frequently induced in Groups A and B.It is concluded that the substrate for sustained ventricular arrhythmia is present in at least 42% of patients after myocardial infarction. The electrophysiologic characteristics of the substrate for ventricular tachycardia seem to be the major determinant of the clinical occurrence of sustained ventricular arrhythmia. Changes in the electrophysiologic properties of the substrate of ventricular tachycardia, either spontaneously with time or induced by ischemia or antiarrhythmic drugs, can contribute to the clinical occurrence of sustained ventricular arrhythmias in patients with an old myocardial infarction

Type 2 Diabetes and Acute Myocardial Infarction. Angiographic Findings and Results of an Invasive Therapeutic Approach in Type 2 Diabetic Versus Nondiabetic Patients

WSTĘP. Śmiertelność wśród chorych na cukrzycę w trakcie zawału serca jest wysoka. Nie ma jednoznacznych danych na temat znaczenia zaawansowania choroby wieńcowej u chorych na cukrzycę typu 2 oraz wpływu zastosowania mechanicznej rewaskularyzacji techniką przezskórnej angioplastyki wieńcowej (PTCA &#8212; percutaneous transluminal coronary angioplasty) na wyniki leczenia chorych z zawałem serca. MATERIAŁ I METODY. Wszyscy chorzy na cukrzycę typu 2 z ostrym zawałem serca (n = 54) zostali prospektywnie włączeni do badania polegającego na natychmiastowym wykonaniu koronarografii i dalszej kwalifikacji do udrożnienia zamkniętegogrupy naczynia metodą PTCA. Oceniano wynik leczenia szpitalnego oraz wynik odległy w porównaniu z losowo wybraną grupą chorych bez cukrzycy (n = 358) włączonych do tego samego badania. WYNIKI. Na podstawie badań angiograficznych wykazano, że miejsca zamknięcia naczyń wieńcowych w obu grupach były podobne. Zmiany wielonaczyniowe i wstrząs kardiogenny występowały częściej w grupie chorych na cukrzycę: 69% vs 51% i 21 vs 10% (p < 0,02). Bezpośredni wynik PTCA w obu grupach był dobry u 90% chorych. Śmiertelność po 30 dniach wyniosła 13% w grupie chorych na cukrzycę typu 2 i 5% wśród chorych bez cukrzycy (p < 0,04). Frakcja wyrzutowa lewej komory w grupie chorych na cukrzycę przed wypisaniem ze szpitala wyniosła 48 &plusmn; 17% vs 55 &plusmn; 15% (p < 0,05). Śmiertelność rok po wypisie wyniosła 11% vs 4%, odpowiednio w grupach z cukrzycą i bez cukrzycy (p < 0,02). Analiza wieloczynnikowa wykazała, że cukrzyca typu 2 jest niezależnym czynnikiem ryzyka śmiertelności wczesnej, ale nie późnej. WNIOSKI. Bezpośrednio wykonywane PTCA jest bezpiecznym i skutecznym postępowaniem u chorych z cukrzycą typu 2 i ostrym zawałem serca. Śmiertelność po 30 dniach w grupie niewyselekcjonowanych chorych na cukrzycę w tym badaniu wyniosła < 15%. Bardziej zaawansowana miażdżyca tętnic wieńcowych oraz wstrząs kardiogenny są odpowiedzialne za większą śmiertelność w przebiegu ostrego zawału serca u chorych na cukrzycę typu 2 w porównaniu z osobami bez cukrzycy.OBJECTIVE. Mortality in diabetic patients with acute myocardial infarction (MI) is high. The significance of the pretreatment coronary status in type 2 diabetic patients with acute MI, as well as the effect of mechanical revascularization using percutaneous transluminal coronary angioplasty (PTCA), has not been established. RESEARCH DESIGN AND METHODS. All patients with type 2 diabetes and acute MI (n = 54) were prospectively enrolled into a study of immediate coronary angiography to guide PTCA of the occluded infarct vessel. Hospital and long-term course were assessed and compared with an unselected control group of nondiabetic patients (n = 358) who were enrolled in the same study. RESULTS. Angiography showed that sites of occlusion and acute coronary flow were similar in both groups. Multivessel disease and shock were more common in type 2 diabetic versus nondiabetic patients: 69 vs. 51% and 21 vs. 10% (P< 0.02), respectively. Direct PTCA was successful in >90% in both groups. Mortality after 30 days was 13% in type 2 diabetic patients versus 5% in patients without diabetes (P< 0.04). Left ventricular (LV) ejection fraction before discharge was lower in diabetic patients (48 &#177; 17 vs. 55 &#177; 15%, P< 0.05). Mortality 1 year after discharge was 11 vs. 4% in diabetic versus nondiabetic patients (P< 0.02). Multivariate analysis identified type 2 diabetes as an independent risk factor for acute, but not for late, mortality. CONCLUSIONS. Direct PTCA is safe and effective in type 2 diabetic patients with acute MI. Mortality after 30 days in unselected diabetic patients i

Twist angle dependent interlayer transfer of valley polarization from excitons to free charge carriers in WSe2_2/MoSe2_2 heterobilayers

We identify an optical excitation mechanism that transfers a valley polarization from photo-excited electron-hole pairs to free charge carriers in twisted WSe$_2$/MoSe$_2$ heterobilayers. For small twist angles, the valley lifetimes of the charge carriers are surprisingly short, despite the occurrence of interlayer excitons with their presumably long recombination and polarization lifetimes. For large twist angles, we measure an increase in both the valley polarization and its respective lifetime by more than two orders of magnitude. Interestingly, in such heterobilayers we observe an interlayer transfer of valley polarization from the WSe$_2$ layer into the MoSe$_2$ layer. This mechanism enables the creation of a photo-induced valley polarization of free charge carriers in MoSe$_2$, which amplitude scales with the gate-induced charge carrier density. This is in contrast to monolayer MoSe$_2$, where such a gate-tunable valley polarization cannot be achieved. By combining time-resolved Kerr rotation, photoluminesence and angle-resolved photoemission spectroscopy measurements with first principles calculations, we show that these findings can be explained by twist angle dependent interlayer scattering mechanisms involving the Q- and $\Gamma$-valleys.Comment: 21 pages, 10 figure

Applying Analysis of Heart Rate Variability in a Pilot Study of Health Effects of Exposure to Chronic Aircraft Noise.

Abstract not availableJRC.H-Institute for environment and sustainability (Ispra

Hyperspectral photoluminescence and reflectance microscopy of 2D materials

Optical micro-spectroscopy is an invaluable tool for studying and characterizing samples ranging from classical semiconductors to low-dimensional materials and heterostructures. To date, most implementations are based on point-scanning techniques, which are flexible and reliable but slow. Here, we describe a setup for highly parallel acquisition of hyperspectral reflection and photoluminescence microscope images using a push-broom technique. Spatial as well as spectral distortions are characterized and their digital corrections are presented. We demonstrate close-to diffraction-limited spatial imaging performance and a spectral resolution limited by the spectrograph. The capabilities of the setup are demonstrated by recording a hyperspectral photoluminescence map of a CVD-grown MoSe$_2$-WSe$_2$ lateral heterostructure, from which we extract the luminescence energies, intensities and peak widths across the interface

Tailoring the dielectric screening in WS2–graphene heterostructures

Abstract The environment contributes to the screening of Coulomb interactions in two-dimensional semiconductors. This can potentially be exploited to tailor material properties as well as for sensing applications. Here, we investigate the tuning of the band gap and the exciton binding energy in the two-dimensional semiconductor WS2 via the external dielectric screening. Embedding WS2 in van der Waals heterostructures with graphene and hBN spacers of thicknesses between one and 16 atomic layers, we experimentally determine both energies as a function of the WS2-to-graphene interlayer distance and the charge carrier density in graphene. We find that the modification to the band gap as well as the exciton binding energy are well described by a one-over-distance dependence, with a significant effect remaining at several nanometers distance, at which the two layers are electrically well isolated. This observation is explained by a screening arising from an image charge induced by the graphene layer. Furthermore, we find that the effectiveness of graphene in screening Coulomb interactions in nearby WS2 depends on its doping level and can therefore be controlled via the electric field effect. We determine that, at room temperature, it is modified by approximately 20% for charge carrier densities of 2 × 1012 cm−2