Discordant Electrocardiogram Left Ventricular Wall Thickness and Strain Findings in Influenza Myocarditis

A 42‐year‐old man presented with a viral prodrome and tested positive for influenza A. He rapidly deteriorated developing cardiogenic shock, rhabdomyolysis, and acute kidney injury. Patient improved 1 week later with supportive measures including vasopressors, inotropes, and an intraaortic balloon pump. We report this case as it highlights the discordance between echocardiographic ventricular wall thickening as a result of myocardial edema, and electrocardiographic findings at presentation, with a reversal in findings at time of resolution. Additionally, there was some suggestion of a regional pattern to the reduced longitudinal strain.     

Screw angulation affects bone-screw stresses and bone graft load sharing in anterior cervical corpectomy fusion with a rigid screw-plate construct: a finite element model study

Background contextAnterior corpectomy and reconstruction with bone graft and a rigid screw-plate construct is an established procedure for treatment of cervical neural compression. Despite its reliability in relieving symptoms, there is a high rate of construct failure, especially in multilevel cases.PurposeThere has been no study evaluating the biomechanical effects of screw angulation on construct stability; this study investigates the C4–C7 construct stability and load-sharing properties among varying screw angulations in a rigid plate-screw construct.Study designA finite element model of a two-level cervical corpectomy with static anterior cervical plate.MethodsA three-dimensional finite element (FE) model of an intact C3–T1 segment was developed and validated. From this intact model, a fusion model (two-level [C5, C6] anterior corpectomy) was developed and validated. After corpectomy, allograft interbody fusion with a rigid anterior screw-plate construct was created from C4 to C7. Five additional FE models were developed from the fusion model corresponding to five different combinations of screw angulations within the vertebral bodies (C4, C7): (0°, 0°), (5°, 5°), (10°, 10°), (15°, 15°), and (15°, 0°). The fifth fusion model was termed as a hybrid fusion model.ResultsThe stability of a two-level corpectomy reconstruction is not dependent on the position of the screws. Despite the locked screw-plate interface, some degree of load sharing is transmitted to the graft. The load seen by the graft and the shear stress at the bone-screw junction is dependent on the angle of the screws with respect to the end plate. Higher stresses are seen at more divergent angles, particularly at the lower level of the construct.ConclusionThis study suggests that screw divergence from the end plates not only increases load transmission to the graft but also predisposes the screws to higher shear forces after corpectomy reconstruction. In particular, the inferior screw demonstrated larger stress than the upper-level screws. In the proposed hybrid fusion model, lower stresses on the bone graft, end plates, and bone-screw interface were recorded, inferring lower construct failure (end-plate fractures and screw pullout) potential at the inferior construct end.     

Guidelines for Cardiac Management in Noncardiac Surgery Are Poorly Implemented in Clinical Practice: Results from a Peripheral Vascular Survey in The Netherlands

Background: The American College of Cardiology (ACC)/American Heart Association (AHA) guidelines for Perioperative Cardiovascular Evaluation for Noncardiac Surgery recommend an algorithm for a stepwise approach to preoperative cardiac assessment in vascular surgery patients. The authors' main objective was to determine adherence to the ACC/AHA guidelines on perioperative care in daily clinical practice.

Methods: Between May and December 2004, data on 711 consecutive peripheral vascular surgery patients were collected from 11 hospitals in The Netherlands. This survey was conducted within the infrastructure of the Euro Heart Survey Programme. The authors retrospectively applied the ACC/AHA guideline algorithm to each patient in their data set and subsequently compared observed clinical practice data with these recommendations.

Results: Although 185 of the total 711 patients (26%) fulfilled the ACC/AHA guideline criteria to recommend preoperative noninvasive cardiac testing, clinicians had performed testing in only 38 of those cases (21%). Conversely, of the 526 patients for whom noninvasive testing was not recommended, guidelines were followed in 467 patients (89%). Overall, patients who had not been tested, irrespective of guideline recommendation, received less cardioprotective medications, whereas patients who underwent noninvasive testing were significantly more often treated with cardiovascular drugs ([beta]-blockers 43% vs. 77%, statins 52% vs. 83%, platelet inhibitors 80% vs. 85%, respectively; all P < 0.05). Moreover, the authors did not observe significant differences in cardiovascular medical therapy between patients with a normal test result and patients with an abnormal test result.     

Isolated profunda femoris insufficiency

Because of rich anastomotic network profunda femoris artery is an important link between iliac and superficial femoral/popliteal circulation and thus isolated insufficiency of profunda is rare. It happened in the case reported herein when patient's own native common femoral artery and its bifurcation was excluded by aorto-femoral and femoro-popliteal bypass graft. Revasculatization of profunda ameliorated the problem.     

Evidence for the presence of a non-catecholamine, clonidine-displacing substance in crude, methanolic extracts of bovine brain and lung

In the present study we have prepared crude, methanolic extracts of bovine lung and bovine brain and, using radioligand binding assays in conjunction with a number of simple chromatographic techniques, provided evidence for the presence of a non-catecholamine ’clonidine-displacing substance‘ (CDS). The level of CDS in lung extracts (9?units/g wet weight n=11) is approximately 3 times that in the brain extracts. Furthermore, the effect of the crude, methanolic extracts are selective for non-adrenoceptor, imidazoline (labelled by [ ³H]-idazoxan) and a ₂-adrenoceptor binding sites (labelled by [ ³H]-clonidine); both extracts are 5–10-fold more potent displacers of ligand binding to a ₂-adrenoceptors compared with binding to opiate receptors (labelled by [ ³H]-etorphine) and practically inactive against a ₁-adrenoceptor and muscarinic binding sites (labelled by [ ³H]- prazosin and [ ³H]-quinuclidinyl benzilate, respectively). With the exception of the non-adrenoceptor, imidazoline binding assay, which used rat kidney membranes labelled by [ ³H]-idazoxan in the presence of the a ₂-adrenoceptor antagonist RS-15385-197, all radioreceptor assays involved bovine cerebral cortex membranes. Although the extracts contain catecholamines (brain only), histamine (lung only) and monovalent cations (both), which have the potential to interfere with the radioligand binding assays, their concentrations were too low to account for the effects observed. Preliminary attempts at purification of the extracts revealed that CDS activities from the two tissues are similar, i.e., practically insoluble in organic solvents at room temperature, not affected by either Sep-Pak C ₁₈ column or anion exchange resins but retained (along with the monovalent cations) by cation exchange resin. However, following chromatographic separation on a Biogel P2 column, the CDS-containing eluates are cation-free and exhibit qualitatively similar elution profiles. Future experiments will involve further purification of ’clonidine-displacing substance‘ to characterize its interaction with a ₂-adrenoceptor binding sites in greater detail and establish whether it has biological activity consistent with the properties implied by its effects in radioligand binding assays.