Signatures of a magnetic-field-induced Lifshitz transition in the ultra-quantum limit of the topological semimetal ZrTe5.

The quantum limit (QL) of an electron liquid, realised at strong magnetic fields, has long been proposed to host a wealth of strongly correlated states of matter. Electronic states in the QL are, for example, quasi-one dimensional (1D), which implies perfectly nested Fermi surfaces prone to instabilities. Whereas the QL typically requires unreachably strong magnetic fields, the topological semimetal ZrTe5 has been shown to reach the QL at fields of only a few Tesla. Here, we characterize the QL of ZrTe5 at fields up to 64 T by a combination of electrical-transport and ultrasound measurements. We find that the Zeeman effect in ZrTe5 enables an efficient tuning of the 1D Landau band structure with magnetic field. This results in a Lifshitz transition to a 1D Weyl regime in which perfect charge neutrality can be achieved. Since no instability-driven phase transitions destabilise the 1D electron liquid for the investigated field strengths and temperatures, our analysis establishes ZrTe5 as a thoroughly understood platform for potentially inducing more exotic interaction-driven phases at lower temperatures.

Effect of timing, technique and molecular features on brain control with local therapies in oncogene-driven lung cancer.

BACKGROUND: The improved efficacy of tyrosine kinase inhibitors (TKI) mandates reappraisal of local therapy (LT) for brain metastases (BM) of oncogene-driven non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: This study included all epidermal growth factor receptor-mutated (EGFR+, n = 108) and anaplastic lymphoma kinase-rearranged (ALK+, n = 33) TKI-naive NSCLC patients diagnosed with BM in the Thoraxklinik Heidelberg between 2009 and 2019. Eighty-seven patients (62%) received early LT, while 54 (38%) received delayed (n = 34; 24%) or no LT (n = 20; 14%). LT comprised stereotactic (SRT; n = 40; 34%) or whole-brain radiotherapy (WBRT; n = 77; 66%), while neurosurgical resection was carried out in 19 cases. RESULTS: Median overall survival (OS) was 49.1 months for ALK+ and 19.5 months for EGFR+ patients (P = 0.001), with similar median intracranial progression-free survival (icPFS) (15.7 versus 14.0 months, respectively; P = 0.80). Despite the larger and more symptomatic BM (P < 0.001) of patients undergoing early LT, these experienced longer icPFS [hazard ratio (HR) 0.52; P = 0.024], but not OS (HR 1.63; P = 0.12), regardless of the radiotherapy technique (SRT versus WBRT) and number of lesions. High-risk oncogene variants, i.e. non-del19 EGFR mutations and 'short' EML4-ALK fusions (mainly variant 3, E6:A20), were associated with earlier intracranial progression (HR 2.97; P = 0.001). The longer icPFS with early LT was also evident in separate analyses of the EGFR+ and ALK+ subsets. CONCLUSIONS: Despite preferential use for cases with poor prognostic factors, early LT prolongs the icPFS, but not OS, in TKI-treated EGFR+/ALK+ NSCLC. Considering the lack of survival benefit, and the neurocognitive effects of WBRT, patients presenting with polytopic BM may benefit from delaying radiotherapy, or from radiosurgery of multiple or selected lesions. For SRT candidates, the improved tumor control with earlier radiotherapy should be weighed against the potential toxicity and the enhanced intracranial activity of newer TKI. High-risk EGFR/ALK variants are associated with earlier intracranial failure and identify patients who could benefit from more aggressive management.

Origin of the quasi-quantized Hall effect in ZrTe5.

The quantum Hall effect (QHE) is traditionally considered to be a purely two-dimensional (2D) phenomenon. Recently, however, a three-dimensional (3D) version of the QHE was reported in the Dirac semimetal ZrTe5. It was proposed to arise from a magnetic-field-driven Fermi surface instability, transforming the original 3D electron system into a stack of 2D sheets. Here, we report thermodynamic, spectroscopic, thermoelectric and charge transport measurements on such ZrTe5 samples. The measured properties: magnetization, ultrasound propagation, scanning tunneling spectroscopy, and Raman spectroscopy, show no signatures of a Fermi surface instability, consistent with in-field single crystal X-ray diffraction. Instead, a direct comparison of the experimental data with linear response calculations based on an effective 3D Dirac Hamiltonian suggests that the quasi-quantization of the observed Hall response emerges from the interplay of the intrinsic properties of the ZrTe5 electronic structure and its Dirac-type semi-metallic character.

Robust Fermi-Surface Morphology of CeRhIn_{5} across the Putative Field-Induced Quantum Critical Point.

We report a comprehensive de Haas-van Alphen (dHvA) study of the heavy-fermion material CeRhIn_{5} in magnetic fields up to 70 T. Several dHvA frequencies gradually emerge at high fields as a result of magnetic breakdown. Among them is the thermodynamically important ß_{1} branch, which has not been observed so far. Comparison of our angle-dependent dHvA spectra with those of the non-4f compound LaRhIn_{5} and with band-structure calculations evidences that the Ce 4f electrons in CeRhIn_{5} remain localized over the whole field range. This rules out any significant Fermi-surface reconstruction, either at the suggested nematic phase transition at B^{*}≈30 T or at the putative quantum critical point at B_{c}≃50 T. Our results rather demonstrate the robustness of the Fermi surface and the localized nature of the 4f electrons inside and outside of the antiferromagnetic phase.

Quantitative ion determination in eccrine sweat gland cells correlates to sweat reduction of antiperspirant actives.

OBJECTIVE: Axillary wetness represents an unwanted effect of the physiologically vital sweating mechanism, especially when it becomes excessive. Cosmetic products reducing sweat secretion rely on aluminium salts as the active ingredient acting by physically blocking the sweat gland. Driven by the interest to better understand the sweat mechanism and to develop alternative technologies against excessive sweating a search for an effective testing approach started as up to now, cost- and time-consuming in vivo studies represent the standard procedure for testing and identifying these alternatives. MATERIAL AND METHODS: The herein described in vitro test system is based on the measurement of intracellular changes of the ion equilibrium in cultured eccrine sweat gland cells. Subsequently, in vivo studies on the back of volunteers were conducted to verify the sweat-reducing effect of in vitro newly discovered substance. RESULTS: In this study, we describe an effective cell-based in vitro method as a potent tool for a more targeted screening of alternatives to aluminium salts. Testing the commonly used aluminium chlorohydrate as one example of an aluminium-based active in this screening procedure, we discovered a distinct influence on the ion equilibrium: Intracellular levels of sodium ions were decreased while those of chloride increased. Screening of various substances revealed a polyethyleneimine, adjusted to pH 3.5 with hydrochloric acid, to evoke the same alterations in the ion equilibrium as aluminium chlorohydrate. Subsequent in vivo studies showed its substantial antiperspirant action and confirmed the high efficiency of the polyethyleneimine solution in vivo. Further, specific investigations connecting the chloride content of the tested substances with the resulting sweat reduction pointed towards a substantial impact of the chloride ions on sweating. CONCLUSION: The newly described in vitro cell-based screening method represents an effective means for identifying new antiperspirant actives and suggests an additional biological mechanism of action of sweat-reducing ingredients which is directed towards unbalancing of the ion equilibrium inside eccrine sweat gland cells.

OBJECTIF: l'humidité axillaire représente un effet indésirable du mécanisme physiologiquement vital de la sudation, en particulier lorsqu'elle devient excessive. Les produits cosmétiques réduisant la sécrétion de sueur reposent sur les sels d'aluminium comme principe actif agissant en bloquant physiquement la glande sudoripare. Motivée par l'intérêt de mieux comprendre le mécanisme de la sudation et de développer des technologies alternatives contre l'hypersudation, une recherche pour une approche de test efficace a commencé car, jusqu'à présent, les études in vivo coûteuses et chronophages représentent la procédure standard pour tester et identifier ces alternatives. MATÉRIELS ET MÉTHODES: le système de test in vitro décrit ici est basé sur la mesure des changements intracellulaires de l'équilibre ionique dans les cellules des glandes sudoripares exocrines cultivées. Par la suite, des études in vivo sur le dos de volontaires ont été menées pour vérifier l'effet réducteur de la sudation d'une substance nouvellement découverte in vitro. RÉSULTATS: dans cette étude, nous décrivons une méthode cellulaire efficace in vitro en tant qu'outil puissant pour un dépistage plus ciblé des alternatives aux sels d'aluminium. En testant le chlorohydrate d'aluminium couramment utilisé comme exemple d'un principe actif à base d'aluminium dans cette procédure de dépistage, nous avons découvert une influence distincte sur l'équilibre ionique : les taux intracellulaires d'ions sodium ont diminué tandis que ceux du chlorure ont augmenté. La recherche de diverses substances a révélé une polyéthylèneimine, ajustée au pH 3,5 avec de l'acide chlorhydrique, pour évoquer les mêmes altérations de l'équilibre ionique que le chlorohydrate d'aluminium. Des études in vivo ultérieures ont montré son action anti-transpirante substantielle et ont confirmé la haute efficacité de la solution de polyéthylèneimine in vivo. De plus, des études spécifiques établissant un lien entre la teneur en chlorure des substances testées et la réduction de la sudation qui en résulte ont indiqué que les ions chlorure ont un impact substantiel sur l'hypersudation. CONCLUSION: la nouvelle méthode de dépistage cellulaire in vitro décrite représente un moyen efficace d'identifier de nouveaux agents anti-transpirants actifs et suggère un mécanisme d'action biologique supplémentaire des ingrédients réducteurs de la sudation, dirigé vers le déséquilibre de l'équilibre ionique à l'intérieur des cellules des glandes sudoripares exocrines.

Unconventional Hall response in the quantum limit of HfTe5.

Interacting electrons confined to their lowest Landau level in a high magnetic field can form a variety of correlated states, some of which manifest themselves in a Hall effect. Although such states have been predicted to occur in three-dimensional semimetals, a corresponding Hall response has not yet been experimentally observed. Here, we report the observation of an unconventional Hall response in the quantum limit of the bulk semimetal HfTe5, adjacent to the three-dimensional quantum Hall effect of a single electron band at low magnetic fields. The additional plateau-like feature in the Hall conductivity of the lowest Landau level is accompanied by a Shubnikov-de Haas minimum in the longitudinal electrical resistivity and its magnitude relates as 3/5 to the height of the last plateau of the three-dimensional quantum Hall effect. Our findings are consistent with strong electron-electron interactions, stabilizing an unconventional variant of the Hall effect in a three-dimensional material in the quantum limit.

FAB: First UK feasibility trial of a future randomised controlled trial of Family focused treatment for Adolescents with Bipolar disorder.

BACKGROUND: This first mixed-methods UK trial examined the feasibility and acceptability of a future definitive randomised controlled trial (RCT) to evaluate whether Family Focussed Treatment for Adolescents with Bipolar Disorder (FFT-A) UK version can improve family functioning and well-being as part of the management of Paediatric Bipolar Disorder (PBD). METHOD: The trial used a randomised, parallel group, non-blinded design where participants received FFT-A UK (16 sessions over 6 months) immediately or after 12 months (delayed arm). Measures of family functioning, well-being and quality of life of the young person and the main carer (most commonly a parent) were completed at baseline, 6 and 12-months in both arms. Primary outcome measures included rates of eligibility, consent and retention along with estimates of variability in the measures and assessment of the intervention delivery. Qualitative interviews allowed assessment of participants' views about FFT-A and the trial processes. RESULTS: Twenty-seven of 36 young persons with PBD and their families consented; of these, 14 families were randomised to the immediate and 13 to the delayed arm. Two families from the immediate arm withdrew consent and discontinued participation. Quantitative measures were completed by 22 families (88%) at 6-months and 21 families (84%) at 12-months. Qualitative interviews were conducted with 30 participants (9 young people, 15 parents and 6 other family members). Nine families attended 3 post-trial focus groups. CONCLUSION: It was feasible to recruit and retain to this trial. The results highlighted that trial design and measures were acceptable to participants. A benefit in family relationships was reported by participants which they attributed to the intervention in qualitative interviews. Families recommended that future modifications include definitive trial(s) recruiting participants in the age range 15-25 years as it felt this was the age range with maximum need. Trial registration ISRCTN, ISRCTN59769322. Registered 20 January 2014, http://www.isrctn.com/ISRCTN59769322.

Fermi surface of LaFe2P2-a detailed density functional study.

Angular-dependent de Haas-van Alphen measurements allow the mapping of Fermi surfaces in great detail with high accuracy. Density functional electronic-structure calculations can be carried out with high precision, but depend crucially on the used structural information and the applied calculational approximations. We report in a detailed study the sensitivity of the calculated electronic band structure of the 122 compound LaFe2P2 on (i) the exact P position in the unit cell, parametrized by a so-called z parameter, and on (ii) the treatment of the La 4f  states. Depending on the chosen exchange and correlation-potential approximation, the calculated z parameter varies slightly and corresponding small but distinctive differences in the calculated band structure and Fermi-surface topology appear. Similarly, topology changes appear when the energy of the mostly unoccupied La 4f  states is corrected regarding their experimentally observed position. The calculated results are compared to experimental de Haas-van Alphen data. Our findings show a high sensitivity of the calculated band structure on the pnictide z position and the need for an accurate experimental determination of this parameter at low temperatures, and a particular need for a sophisticated treatment of the La 4f  states. Thus, this is not only crucial for the special case of LaFe2P2 studied here, but of importance for the precise determination of the band structure of related 122 materials and La containing compounds in general.

The right atrium in idiopathic hypereosinophilic syndrome : Insights from the 3D speckle tracking echocardiographic MAGYAR-Path Study.

BACKGROUND: Idiopathic hypereosinophilic syndrome is characterized by a persistent eosinophil blood count of >1.5 × 109 cells/l and organ damage, independent of the primary and secondary causes of eosinophilia. The purpose of the present study was to assess the three-dimensional speckle tracking echocardiography-derived right atrial volumetric and functional properties between hypereosinophilic syndrome patients and matched controls. METHODS: A total of 11 patients with idiopathic hypereosinophilic syndrome and 22 age- and gender-matched healthy controls were enrolled in the study. Three-dimensional speckle tracking echocardiography was used for calculation of right atrial volumes, volume-based functional properties, and strain parameters. RESULTS: Significantly increased right atrial maximum (68.7 ± 33.1 ml vs. 40.3 ± 12.1 ml, respectively; p = 0.001) and minimum volumes (48.3 ± 31.0 ml vs. 28.3 ± 9.4 ml, respectively; p = 0.009), as well as right atrial volume before atrial contraction (58.6 ± 27.3 ml vs. 34.5 ± 11.8 ml, respectively; p = 0.001), were found in hypereosinophilic syndrome patients compared with controls. Total and passive right atrial stroke volumes proved to be significantly increased in hypereosinophilic syndrome patients. However, global and mean segmental strain parameters did not differ significantly between the groups. CONCLUSION: Increased cyclic right atrial volumes and mild alterations in right atrial functional properties could be demonstrated in idiopathic hypereosinophilic syndrome patients.

Left ventricular rotational mechanics differ between lipedema and lymphedema: Insights from the three-dimensional speckle tracking echocardiographic MAGYAR-path study.

The present study aimed to assess LV rotational mechanics by three-dimensional speckle-tracking echocardiography (3DSTE) in lipedema (n=25), lymphedema (n=26) patient groups with age- and gender-matched healthy controls (n=54). 3 lipedema and 4 lymphedema patients were excluded due to insufficient image quality for 3DSTE analysis. LV apical rotation (9.61 ± 4.25 degree vs. 6.40 ± 2.63 degree, p <0.05) and LV twist (13.83 ± 4.89 degree vs. 10.04 ± 3.56 degree, p <0.05) are impaired in lipedema patients as compared to matched controls; similar alterations in lymphedema were not found. Moreover, in some lipedema and lymphedema patients severe LV rotational abnormalities could be detected. Our results suggest that lipedema-associated impaired LV apical rotation and twist assessed by 3DSTE could be a novel differential diagnostic point between lipedema and lymphedema.

Selective mass enhancement close to the quantum critical point in BaFe2(As1-x P x )2.

A quantum critical point (QCP) is currently being conjectured for the BaFe2(As1-x P x )2 system at the critical value x c ≈ 0.3. In the proximity of a QCP, all thermodynamic and transport properties are expected to scale with a single characteristic energy, given by the quantum fluctuations. Such a universal behavior has not, however, been found in the superconducting upper critical field H c2. Here we report H c2 data for epitaxial thin films extracted from the electrical resistance measured in very high magnetic fields up to 67 Tesla. Using a multi-band analysis we find that H c2 is sensitive to the QCP, implying a significant charge carrier effective mass enhancement at the doping-induced QCP that is essentially band-dependent. Our results point to two qualitatively different groups of electrons in BaFe2(As1-x P x )2. The first one (possibly associated to hot spots or whole Fermi sheets) has a strong mass enhancement at the QCP, and the second one is insensitive to the QCP. The observed duality could also be present in many other quantum critical systems.

Is there a relationship between increased aortic stiffness and segmental left ventricular deformation in elite athletes? (Insights from the MAGYAR-Sport Study).

Introduction Myocardial contractility of the left ventricle (LV) is related to arterial distensibility. Sport activity is frequently associated with changes in both LV and arterial functions. This study aimed to find correlations between three-dimensional speckle-tracking echocardiography-derived segmental LV deformation parameters and echocardiographically assessed aortic stiffness index (ASI) in athletes. This study comprised 26 young elite athletes (mean age: 26.7 ± 8.4 years, nine men). Results Among segmental circumferential strains (CSs), only that of apical anterior (r = 0.40, p = 0.05), septal (r = 0.47, p = 0.01), inferior (r = 0.59, p = 0.001), lateral (r = 0.44, p < 0.05), and midventricular anteroseptal (r = 0.44, p < 0.05) segments correlated with ASI, whereas LV-CS of the midventricular anterior segment showed a correlation tendency. Only longitudinal strain of basal anteroseptal (r = -0.46, p < 0.05) and inferoseptal (r = -0.57, p < 0.01) segments showed correlations with ASI, whereas that of the basal anterior segment had only a tendency to correlate. Some segmental multidirectional strains also correlated with ASI. Conclusions Correlations could be demonstrated between increased aortic stiffness and circular function of the apical and midventricular LV fibers and longitudinal motion of the basal septum and LV anterior wall (part of LV outflow tract) in maintaining circulation in the elite athletes.

Late cardiac effect of anthracycline therapy in physically active breast cancer survivors - a prospective study.

The late-onset cardiotoxic effect of anthracycline is known, however the early detection and prevention of subclinical myocardial damage has not been fully understood yet. Besides medical therapy regular physical activities may also play a role in the prevention and reduction of side effects of chemotherapy. The aim of our present study was to detect the effect of regular physical activities on the diastolic function and on the symptoms of late heart failure in case of anthracycline chemotherapy. The prospective study included 55 female patients (age 31-65 year, average 49.5 years) with breast cancer and no cardiovascular risk factors. Proper cardiologic checkup included physical examination (blood pressure, pulse, etc.), ECG, standard echocardiography parameters (EF, LV dimensions etc.) and specific tissue Doppler (TDI) measurements. Symptoms of heart failure were also recorded. After five years of follow-up, symptoms of heart failure were evaluated again. Patients were assigned into two groups depending on their physical activity: 36 patients did perform regular physical activities (mean age 49.2 years) and 19 patients did not (average age 50.1 years). There was no significant difference between the two groups in basic physiological or standard echocardiography parameters neither at the baseline nor at the later time points. Diastolic dysfunction (decreased E/A) was detected 6 months after the beginning of the treatment (T2 time point) in both groups. In the inactive group this value fell below one however there was no significant difference (1.1±0.25 vs. 0.95±0.22). One year after the beginning of the treatment (T3) a significant difference could be detected between the two groups (1.05±0.28 vs. 0.86±0.25. P=0.038). Consistent change in diastolic function (Ea/Aa) could be detected with the more sensitive TDI (Tissue Doppler Imaging) measurements after treatments in both groups, especially in the septal segment (in the non active group the Ea/Aa decreased markedly but not significantly at T2 - 1.1±0.55 vs. 0.81±0.44, and this difference became significant at T3 and 2 years after treatment (T4), p=0.007 and p=0.065). The filling pressure (E/Ea) rose above 10 (p=0.09) in the non active group at T2; and it kept rising in both groups and became significant at T3 (p=0.012). Five years after the onset of the treatment symptoms of heart failure were less frequently reported in the physically active group than in the inactive one (19.45% vs. 68.42%). The data of our study show that the diastolic dysfunction of the left ventricle related to the anthracycline therapy became evident in the physically active group later and the symptoms of heart failure were less frequent than in the non active group after five years period. Enrollment in sport activities could be a good means for partial prevention in this group of patients. Cardiologic checkup at proper intervals plays a pivotal role in detection of possible cardiotoxicity. This is a strong indication for changes in the lifestyle of the patient and the treatment protocol alike.

Hyperventilation assists proarrhythmia development during delayed repolarization in clofilium-treated, anaesthetized, mechanically ventilated rabbits.

Hyperventilation reduces partial pressure of CO2 (PCO2) in the blood, which results in hypokalaemia. Hypokalaemia helps the development of the life-threatening torsades de pointes type ventricular arrhythmia (TdP) evoked by repolarization delaying drugs. This implies that hyperventilation may assist the development of proarrhythmic events. Therefore, this study experimentally investigated the effect of hyperventilation on proarrhythmia development during delayed repolarization. Phenylephrine (an α1-adrenoceptor agonist) and clofilium (as a representative repolarization delaying agent inhibiting the rapid component of the delayed rectifier potassium current, IKr) were administered intravenously to pentobarbital-anaesthetized, mechanically ventilated, open chest rabbits. ECG was recorded, and the onset times and incidences of the arrhythmias were determined. Serum K+, pH and PCO2 were measured in arterial blood samples. Clofilium prolonged the rate corrected QT interval. TdP occurred in 15 animals (TdP+ group), and did not occur in 14 animals (TdP- group). We found a strong, positive, linear correlation between serum K+ and PCO2. There was no relationship between the occurrence of TdP and the baseline K+ and PCO2 values. However, a positive, linear correlation was found between the onset time of the first arrhythmias and the K+ and PCO2 values. The regression lines describing the relationship between PCO2 and onset time of first arrhythmias were parallel in the TdP+ and TdP- groups, but the same PCO2 resulted in earlier arrhythmia onset in the TdP+ group than in the TdP- group. We conclude that hyperventilation and hypocapnia with the resultant hypokalaemia assist the multifactorial process of proarrhythmia development during delayed repolarization. This implies that PCO2 and serum K+ should be controlled tightly during mechanical ventilation in experimental investigations and clinical settings when repolarization-delaying drugs are applied.

[Epileptic seizure-induced vertebral body fractures]. / Wirbelkörperfrakturen im Rahmen eines generalisierten epileptischen Anfalls.

In the literature epilepsy is described as the most common cause of generalized seizures. Vertebral body fractures are a rare complication of epileptic convulsions, occurring with an incidence of 3%. We present the case of a 37-year-old healthy patient, who sustained contiguous fractures of the thoracic and lumbar spine during the first manifestation of epilepsy with primary localized and then secondary generalized epileptic seizures. A complication-free outcome was achieved with a combination of conservative and operative therapies.

Correlations between three-dimensional speckle-tracking echocardiography-derived left atrial functional parameters and aortic stiffness in healthy subjects - Results from the MAGYAR-Healthy Study.

UNLABELLED: Left atrial (LA) distension has been demonstrated to be linked with aortic stiffness in different patient populations. Three-dimensional (3D) speckle-tracking echocardiography (STE) seems to be a promising tool for volumetric and functional evaluation of the LA. The aim of the present study was to determine whether correlations exist between 3DSTE-derived LA volume-based and strain parameters characterizing all phasic functions of the LA and echocardiographic aortic elastic properties in healthy subjects. The study included 19 healthy volunteers (mean age: 37.9 ± 11.4 years, 11 men) who had undergone complete two-dimensional (2D) Doppler transthoracic echocardiography extended with the assessment of aortic elastic properties and 3DSTE. RESULTS: None of LA volumes correlated with echocardiographic aortic elastic properties. Active atrial stroke volume correlated with aortic stiffness index (ASI, r = 0.45, p = 0.05). None of other volume-based functional properties significantly correlated with aortic stiffness parameters. Global peak 3D strain correlated with aortic strain (r = ‒0.46, p = 0.05). global radial pre-atrial contraction strain correlated with ASI (r = ‒0.49, p = 0.04) and AS (r = ‒0.50, p = 0.04). CONCLUSIONS: Correlations exist between 3DSTE-derived LA functional parameters and eschocardiographic aortic elastic properties in healthy subjects.

Prediction of myocardial tissue loss by quantitative densitometric myocardial blush parameters following ST-elevation myocardial infarction.

UNLABELLED: Tissue level myocardial perfusion is one of the most important prognostic factors after successful recanalisation of the occluded coronary artery in patients suffering acute ST elevation myocardial infarction (STEMI). The primary objective of the present study was to examine the relationship between videodensitometric myocardial perfusion parameters as assessed on coronary angiograms directly following successful recanalization therapy and magnetic resonance imaging (MRI)-derived myocardial tissue loss late after STEMI. The study comprised 29 STEMI patients. Videodensitometric parameter G(max)/T(max) was calculated to characterize myocardial perfusion, derived from the plateau of grey-level intensity (G(max)), divided by the time-to-peak intensity (Tmax). Myocardial loss index (MLI) was assessed by cardiac MRI following 376 ± 254 days after PCI. RESULTS: Significant correlations could be demonstrated between MLI and G(max) (r = 0.36, p = 0.05) and G(max)/T(max) (r = 0.40, p = 0.03) using vessel masking. Using receiver operating characteristic curve analysis, G(max)/T(max) < 2.17 predicted best MLI = 0.3, 0.4, 0.5 and 0.6 with good sensitivity and specificity data, while G(max)/T(max) < 3.25 proved to have a prognostic role in the prediction of MLI = 0.7. CONCLUSIONS: Selective myocardial tissue level perfusion quantitative measurement method is feasible and can serve as a good predictor of myocardial tissue loss following STEMI and revascularization therapy.

Videodensitometric time-density curve change after alcohol septal ablation of obstructive hypertrophic cardiomyopathy.

A recently developed computerized method for estimation of myocardial perfusion, based on the analysis of the time-density curves, is demonstrated to assess myocardial blush over a selected myocardial region of interest in a patient with obstructive hypertrophic cardiomyopathy before and after alcohol septal ablation.