Connecting structurally and dynamically detected signatures of supramolecular Debye liquids

The monohydroxy alcohol 2-ethyl-1-hexanol mixed with the halogen-substituted alkyl halides 2-ethyl-1-hexyl chloride and 2-ethyl-1-hexyl bromide was studied using synchrotron-based x-ray scattering. In the diffraction patterns, an oxygen-related prepeak appears. The concentration dependence of its intensity, shape, and position indicates that the formation of the hydrogen-bonded associates of monohydroxy alcohols is largely hindered by the halogen alkane admixture. Using dielectric spectroscopy and high-resolution rheology on the same liquid mixtures, it is shown that these structural features are correlated with the relaxation mechanisms giving rise to supramolecular low-frequency dynamics.

Two-site jumps in dimethyl sulfone studied by one- and two-dimensional 17O NMR spectroscopy

Polycrystalline dimethyl sulfone is studied using central-transition oxygen-17 exchange NMR. The quadrupolar and chemical shift tensors are determined by combining quantum chemical calculations with line shape analyses of rigid-lattice spectra measured for stationary and rotating samples at several external magnetic fields. Quantum chemical computations predict that the largest principal axes of the chemical shift anisotropy and electrical field gradient tensors enclose an angle of about 73°. This prediction is successfully tested by comparison with absorption spectra recorded at three different external magnetic fields. The experimental one-dimensional motionally narrowed spectra and the two-dimensional exchange spectrum are compatible with model calculations involving jumps of the molecules about their two-fold symmetry axis. This motion is additionally investigated by means of two-time stimulated-echo spectroscopy which allows for a determination of motional correlation functions over a wider temperature range than previously reported using carbon and deuteron NMR. On the basis of suitable second-order quadrupolar frequency distributions, sin-sin stimulated-echo amplitudes are calculated for a two-site model in the limit of vanishing evolution time and compared with experimental findings. The present study thus establishes oxygen-17 NMR as a powerful method that will be particularly useful for the study of solids and liquids devoid of nuclei governed by first-order anisotropies.

Effects of Short Term Adiponectin Receptor Agonism on Cardiac Function and Energetics in Diabetic db/db Mice

Objective

Impaired cardiac efficiency is a hallmark of diabetic cardiomyopathy in models of type 2 diabetes. Adiponectin receptor 1 (AdipoR1) deficiency impairs cardiac efficiency in non-diabetic mice, suggesting that hypoadiponectinemia in type 2 diabetes may contribute to impaired cardiac efficiency due to compromised AdipoR1 signaling. Thus, we investigated whether targeting cardiac adiponectin receptors may improve cardiac function and energetics, and attenuate diabetic cardiomyopathy in type 2 diabetic mice.

Methods

A non-selective adiponectin receptor agonist, AdipoRon, and vehicle were injected intraperitoneally into Eight-week-old db/db or C57BLKS/J mice for 10 days. Cardiac morphology and function were evaluated by echocardiography and working heart perfusions.

Results

Based on echocardiography, AdipoRon treatment did not alter ejection fraction, left ventricular diameters or left ventricular wall thickness in db/db mice compared to vehicle-treated mice. In isolated working hearts, an impairment in cardiac output and efficiency in db/db mice was not improved by AdipoRon. Mitochondrial respiratory capacity, respiration in the presence of oligomycin, and 4-hydroxynonenal levels were similar among all groups. However, AdipoRon induced a marked shift in the substrate oxidation pattern in db/db mice towards increased reliance on glucose utilization. In parallel, the diabetes-associated increase in serum triglyceride levels in vehicle-treated db/db mice was blunted by AdipoRon treatment, while an increase in myocardial triglycerides in vehicle-treated db/db mice was not altered by AdipoRon treatment.

Conclusion

AdipoRon treatment shifts myocardial substrate preference towards increased glucose utilization, likely by decreasing fatty acid delivery to the heart, but was not sufficient to improve cardiac output and efficiency in db/db mice.

Electrocardiographic changes after TAVR and their clinical impact according to new ESC Pacing Guidelines

 

Conduction disturbances after transcatheter aortic valve replacement (TAVR) remain one of the most frequent complications.

The aim of this study was to analyze ECG changes after TAVR using contemporary valves and to detect risk factors for the need of further clinical evaluation according to new ESC pacing guidelines to evaluate pacemaker implantation.

In this retrospective analysis we included 850 patients (mean age 80±9 years, 51% female), who underwent TAVR in our institution from January 2019 until December 2020. A mean follow-up of 8.9±8.4 months and 217 (25.5%) patients was performed.

55% of the implanted valves were self-expandable, 45% balloon-expandable. After TAVR, 77 (9.1%) patients developed new LBBB and QRS >150ms, 26 (3.1%) new PR-time >240ms. Prolongation of PR-time and prolongation of QRS duration >20ms were seen in 20 (2.4%) and 90 (10.6%) patients with preexisting conduction disturbances. 152 (17.9%) patients needed pacemaker implantation post TAVR.

Developing a PR-prolongation of >20ms was associated with calcification of the annulus (OR 1.2 CI 95% 1.004–1.4; p=0.04). New LBBB (OR 0.45; CI 95% 0.25–0.79; p=0.006) and pacemaker implantation (OR 0.4; CI 95% 0.2–0.8; p=0.009) were correlated with the implantation of a self-expandable valve. Coronary heart disease (OR 3, CI 95% 1.07–8.2; p=0.04) and peripheral arterial disease (OR 2.6 CI 95% 1.18–5.6; p=0.02) were associated with prolongation of QRS >20ms. New LBBB with QRS >150ms was seen more often after post-dilatation (OR 1.03, CI 95% 1.01–1.05; p=0.05). Pre-existing AV block I° (OR 2.8, CI 95% 1.4–5.6; p<0.001), pre-existing RBBB (OR 20.5, CI 95% 7.5–56; p<0.001), nicotine abuse (OR 2, CI 95% 1.05–3.8; p=0.04), prosthesis oversizing (OR 1.06, CI 95% 1.006–1.11; p=0.03) and implantation depth (OR 1.13, CI 95% 1.006–1.26; p=0.04) were independent risk factors for pacemaker implantation.

During the follow-up 161 patients (18.9%) were hospitalized in 270 inpatient stays [cardiac decompensation (n=36, 13%), pacemaker implantation (n=9, 3.3%), acute coronary syndrome (n=12, 4.4%)]. 8 patients (80%) received a pacemaker implantation because of AV Block III° and 1 (10%) patient because of sick-sinus-syndrome (SSS). Analyzing the post TAVR ECG 5 (50%) had a new LBBB (3 (30%) with QRS >150ms) and 4 (40%) patients showed LBBB together with AV Block I°.

According to new guidelines 213 (25.1%) patients would have needed further clinical evaluation (EP study or ECG monitoring) after TAVR. AV-conduction abnormalities were associated with annulus calcification. Self-expandable valves were associated with new LBBB and pacemaker implantation. There seems to be a correlation between arteriosclerotic diseases and QRS width post TAVR. Pre-existing RBBB, AV block I°, implantation depth and prosthesis oversizing are important risk factors for pacemaker implantation post TAVR. New LBBB after TAVR is associated with a higher risk for pacemaker implantation in the long-term analysis.

Funding Acknowledgement

Type of funding sources: None.

[Thiopental levels in the plasma during induction of anesthesia]

The thiopentone sodium surge in plasma was investigated in 15 elderly surgical patients and 10 young adults during injection, over a period of 1 minute, of 4 mg of anaesthetic per kg of fat-free body weight (in 18 patients), and 5 mg per kg of fat-free body weight (7 patients). In keeping with prolonged circulation time in old age, thiopentone sodium reached the sampling site faster in the younger patients than it did in the older patients. In the majority of cases, thiopentone sodium concentrations in plasma reached a maximum of between 60 and 80 micrograms/ml. Mean thiopentone sodium concentrations in the older patients were 10% higher, but here values differed so widely that this result must be regarded as coincidental. It was, accordingly, impossible to establish any statistically verifiable differences between young and old patients by estimating the volume of thiopentone sodium distribution shortly after the end of injection. Plasma protein binding, 85% on average, with extremes ranging from 79% to 89% did not depend on thiopentone concentration or age. In the group of patients studied, it was not possible to confirm statistically that the plasma protein concentration influenced the rate of binding. Dosage according to fat-free body weight did not diminish inter-individual differences in plasma concentration-time profiles.

Medical graphics to improve patient understanding and anxiety in elderly and cognitively impaired patients scheduled for transcatheter aortic valve implantation (TAVI)

BACKGROUND

Anxiety and limited patient comprehension may pose significant barriers when informing elderly patients about complex procedures such as transcatheter aortic valve implantation (TAVI).

OBJECTIVES

We aimed to evaluate the utility of medical graphics to improve the patient informed consent (IC) before TAVI.

METHODS

In this prospective, randomized dual center study, 301 patients were assigned to a patient brochure containing medical graphics (Comic group, n = 153) or sham information (Control group, n = 148) on top of usual IC. Primary outcomes were patient understanding of central IC-related aspects and periprocedural anxiety assessed by the validated Spielberger State Trait Anxiety Inventory (STAI), both analyzed by cognitive status according to the Montreal Cognitive Assessment (MoCA).

RESULTS

Patient understanding was significantly higher in the Comic group [mean number of correct answers 12.8 (SD 1.2) vs. 11.3 (1.8); mean difference 1.5 (95% CI 1.2-1.8); p < 0.001]. This effect was more pronounced in the presence of cognitive dysfunction (MoCA < 26) [12.6 (1.2) in the Comic vs. 10.9 (1.6) in the Control group; mean difference 1.8 (1.4-2.2), p < 0.001]. Mean STAI score declined by 5.7 (95% CI 5.1-6.3; p < 0.001) in the Comic and 0.8 points (0.2-1.4; p = 0.015) in the Control group. Finally, mean STAI score decreased in the Comic group by 4.7 (3.8-5.6) in cognitively impaired patients and by 6.6 (95% CI 5.8 to 7.5) in patients with normal cognitive function (p < 0.001 each).

CONCLUSIONS

Our results prove beneficial effects for using medical graphics to inform elderly patients about TAVI by improving patient understanding and reducing periprocedural anxiety (DRKS00021661; 23/Oct/2020).

Distal versus proximal radial access in coronary angiography: a meta-analysis

BACKGROUND

Distal radial access (DRA) represents a promising alternative to conventional proximal radial access (PRA) for coronary angiography. Substantial advantages regarding safety and efficacy have been suggested for DRA, but the ideal access route remains controversial.

AIMS

The aim of this study was to compare safety, efficacy and feasibility of DRA to PRA.

METHODS

National Library of Medicine PubMed, Web of Science, clinicaltrials.gov and Cochrane Library were systematically searched for randomized controlled trials and registry studies comparing DRA and PRA that were published between January 1, 2017 and April, 2024. Primary endpoint was the rate of radial artery occlusion (RAO). Secondary endpoints were access failure, access time, procedure time, arterial spasm, hematoma, and hemostasis time. Data extraction was performed by two independent investigators. Relative risks were aggregated using a random effects model. We applied meta-analytic regression to assess study characteristic variables as possible moderators of the study effects.

RESULTS

44 studies with a total of 21,081 patients were included. We found a significantly lower rate of RAO after DRA (DRA 1.28%, PRA 4.76%, p < .001) with a 2.92 times lower risk compared to the proximal approach (Log Risk Ratio = -1.07, p < .001). Conversely, the risk for access failure was 2.42 times higher for DRA compared to PRA (Log Risk Ratio = 0.88, p < .001).

CONCLUSION

In this largest meta-analysis to date, we were able to show that rates of RAO are reduced with DRA compared to conventional PRA. This suggests DRA is a safe alternative to PRA.