Disastrous physiological effects of saline on the cell membrane demonstrated in cardiac cells

Objective—Saline is not an ideal storage solution. It has a low pH, no buffering capacity, and lacks other ions and nutrients. The objective was to explore the effects of storing cardiac muscle in saline.

Design—Guinea pig papillary muscles and ventricular myocytes were exposed to saline. The effects on action potential, membrane current, contraction and cell shortening were recorded in vitro at 35–37°C.

Results—Saline caused transient hyperpolarization of the resting potential (?140?mV), prolonged duration of the action potential, and increased contraction amplitude, which was later reversed. The membrane resting potential depolarized after a few minutes to about ?15?mV and the preparations became unexcitable. The depolarized preparations remained slightly contracted. Upon reperfusion both papillary muscles and cells became unstable and spontaneously active. Storing myocytes in saline for only 2?h resulted in excessive cell death.

Conclusion—Saline is disastrous for the function of the heart muscle and leads to depolarization, sustained contraction and unexcitable tissue. Saline should not be used as a storage medium, even for short periods of time.     

Open versus arthroscopic subacromial decompressionA prospective,randomized study of 34 patients followed for 8 years

In a randomized prospective study, we selected 15 patients for arthroscopic subacromial decompression (ASD) and 19 patients for open subacromial decompression (OSD). All had impingement syndrome (Neer grade II), and had been unsuccessfully treated without surgery for more than 6 months. The UCLA Shoulder Rating Scale, Visual Analogue Scales for pain and satisfaction, isokinetic dynamometer recordings and physical testing were assessed preoperatively and at 1 (except isokinetic testing), 3, 6, and 12 months, and, finally, 8 years after surgery. We found essentially no differences in the clinical tests between the groups during this period. The use of ASD or OSD seems to be a matter of cosmesis and personal preference.     

Behandlungsmanagement von Bissverletzungen der Hand und des Unterarms

The frequency of minor bite injuries cannot be safely estimated because many patients do not seek medical treatment or are treated conservatively. Complex injuries are treated surgically according to the known concept for complex injuries of the hand. Bite injuries with secondary infections represent a special challenge and should be treated in departments for hand surgery because a delay in treatment will lead to a poor functional outcome.     

Clinical features,exercise hemodynamics,and determinants of left ventricular elevated filling pressure in heart‐transplanted patients

This study aimed to assess clinical, functional, and hemodynamic characteristics of heart‐transplanted (HTX) patients during exercise. We performed comprehensive echocardiographic graft function assessment during invasive hemodynamic semi‐supine exercise test in 57 HTX patients. According to hemodynamics findings, patients were divided into Group A: normal left ventricular (LV) filling pressure (FP): pulmonary capillary wedge pressure (PCWP) <15 mmHg at rest and <25 mmHg at peak exercise, and Group B: elevated LV‐FP: PCWP ≥15 mmHg at rest or ≥25 mmHg at peak exercise. Thirty‐one patients (54%) had normal LV‐FP and 26 patients (46%) had elevated LV‐FP. The latter had higher cumulative rejection burden (P < 0.01) and were more symptomatic (NYHA class >1) (P < 0.05), and cardiac allograft vasculopathy (CAV) was more prevalent (P < 0.05). With exercise, the changes in both left‐ and right‐sided filling pressures were significantly increased, whereas LV longitudinal myocardial deformation was lower (P < 0.05) in patients with elevated LV‐FP than in patients with normal LV‐FP. No between‐group difference was observed for cardiac index or LV ejection fraction (LVEF) during exercise. In conclusion, elevated LV‐FP can be demonstrated in approximately 50% of HTX patients. Patients with elevated LV‐FP have impaired myocardial deformation capacity, higher prevalence of CAV, and higher rejection burden, and were more symptomatic. Exercise test with the assessment of longitudinal myocardial deformation should be considered in routine surveillance of HTX patients as a marker of restrictive filling (ClinicalTrials.gov Identifier: NCT02077764).     

Estimation of the duration of ventricular fibrillation using ECG single feature analysis

The duration of untreated ventricular fibrillation (VF) is of paramount importance for CPR success. Moreover, therapeutic interventions taking into account the interval between cardiac arrest onset and initiation of CPR improve outcome. This study was performed to investigate whether VF feature analysis could be used to estimate the duration of VF in patients with out-of-hospital cardiac arrest. Demographic data recorded according to the Utstein guidelines and ECG recordings of 376 cardiac arrest patients from three European areas were analysed. Ten features in the time and frequency domain derived from different sub-bands of the initial VF ECG (n=127) were evaluated. The correlation between VF ECG features and cardiac arrest times was investigated using Pearson's correlation coefficient in a subset of 40 patients with reliably estimated downtimes and artefact-free initial VF tracings. No significant correlation (p<.05) between any of the VF ECG features and downtime could be found. The duration of cardiac arrest could not be estimated reliably from human VF ECG single feature analysis.     

Shear stress-induced changes in atherosclerotic plaque composition are modulated by chemokines

We previously found that low shear stress (LSS) induces atherosclerotic plaques in mice with increased lipid and matrix metalloproteinase content and decreased vascular smooth muscle and collagen content. Here, we evaluated the role of chemokines in this process, using an extravascular device inducing regions of LSS, high shear stress, and oscillatory shear stress (OSS) in the carotid artery. One week of shear stress alterations induced expression of IFN-gamma-inducible protein-10 (IP-10) exclusively in the LSS region, whereas monocyte chemoattractant protein-1 (MCP-1) and the mouse homolog of growth-regulated oncogene alpha (GRO-alpha) were equally upregulated in both LSS and OSS regions. After 3 weeks, GRO-alpha and IP-10 were specifically upregulated in LSS regions. After 9 weeks, lesions with thinner fibrous caps and larger necrotic cores were found in the LSS region compared with the OSS region. Equal levels of MCP-1 expression were observed in both regions, while expression of fractalkine was found in the LSS region only. Blockage of fractalkine inhibited plaque growth and resulted in striking differences in plaque composition in the LSS region. We conclude that LSS or OSS triggers expression of chemokines involved in atherogenesis. Fractalkine upregulation is critically important for the composition of LSS-induced atherosclerotic lesions.