In recent years, pacemaker lead failure due to compressive damage has been reported with increasing frequency. To document the mechanism of this failure, we evaluated explanted mechanically damaged leads with electrical testing, optical microscopy, and in some cases, scanning electron microscopy (SEM). In addition, we performed an autopsy study to measure the compressive loads on catheters placed percutaneously through the costoclavicular angle, as well as by cephalic cutdown. Of the 49 explanted compression damaged leads with enough clinical data for analysis, all had been placed by percutaneous subclavian puncture. Our autopsy data confirmed the significant increase in pressures generated in the costoclavicular angle for medial percutaneous subclavian catheterization (126 +/- 26 mmHg) compared to a more lateral percutaneous subclavian puncture (63 +/- 15 mmHg) or a cephalic cutdown (38 +/- 13 mmHg) (P < 0.01). In vivo coil compression testing documented loads up to 100 pounds per linear inch of coil and a compressive morphology by SEM identical to that seen in the clinical explants. Pacemaker leads appear to be susceptible to compression damage when placed by subclavian venipuncture. When possible, leads should be placed such that they avoid the tight costoclavicular angle.
The purpose of this study was to document recovery following a pitching performance and determine if prolonged post-game phase change material (PCM) cooling of the shoulder and forearm accelerates recovery. Methods: Strength, soreness and serum creatine kinase (CK) activity were assessed prior to, and on the two days following pitching performances in 16 college pitchers. Pitchers were randomized to receive either post-game PCM cooling packs on the shoulder and forearm, or no cooling (control). PCM packs were applied inside compression shirts and delivered cooling at a constant temperature of 15°C for 3 hours. Strength was assessed for shoulder internal rotation (IR), external rotation (ER), empty can test (EC) and grip. Results: Total pitch count was 60±16 for 23 PCM cooling games and 62±17 for 24 control games (P=.679). On the days following pitching IR strength (P=.006) and grip strength (P=.036) were higher in the PCM cooling group versus control. One day after pitching IR strength was 95±14% of baseline with PCM cooling versus 83±13% for control (P=.008, effect size d 0.91) and 107±9% versus 95±10% for grip strength (P=.022, effect size d 1.29). There was a trend for greater ER strength with PCM cooling (P=.091, effect size d 0.51). The EC strength was not impaired after pitching (P=.147) and was therefore unaffected by PCM cooling (P=.168). Elevations in soreness and CK were not different between treatments (Treatment by Time CK P=.139, shoulder soreness P=.885, forearm soreness P=.206). Conclusion: This is one of the first studies to document impairments in muscle function on the days following baseball pitching, and the first study showing a novel cryotherapy intervention that accelerates recovery of muscle function in baseball pitchers following a game. 2
Direct ophthalmoscopy is an integral part of the physical examination and is the most widely used technique to assess the fundus, especially in primary care. The gold standard slit-lamp technique is used in specialty clinics and in some EDs. Most medical professionals own smartphones, and a smartphone ophthalmoscope could bring the quality of a slit-lamp examination into primary care. Imaging techniques with smartphones are easy to learn and use, providing a significant step toward reversing the lack of confidence that students and clinicians have in traditional methods. Current evidence supports the potential of smartphone imaging to replace direct ophthalmoscopy in primary care settings.
We apply the recently developed symbolic resonance analysis to electroencephalographic measurements of event-related brain potentials ͑ERPs͒ in a language processing experiment by using a three-symbol static encoding with varying thresholds for analyzing the ERP epochs, followed by a spin-flip transformation as a nonlinear filter. We compute an estimator of the signal-to-noise ratio ͑SNR͒ for the symbolic dynamics measuring the coherence of threshold-crossing events. Hence, we utilize the inherent noise of the EEG for sweeping the underlying ERP components beyond the encoding thresholds. Plotting the SNR computed within the time window of a particular ERP component ͑the N400͒ against the encoding thresholds, we find different resonance curves for the experimental conditions. The maximal differences of the SNR lead to the estimation of optimal encoding thresholds. We show that topographic brain maps of the optimal threshold voltages and of their associated coherence differences are able to dissociate the underlying physiological processes, while corresponding maps gained from the customary voltage averaging technique are unable to do so.
Evidence for behavior modification for improved health outcomes was evaluated for nutrition, physical activity (PA), and indoor environmental quality (IEQ). The databases searched included LISTA, PubMed, and Web of Science, with articles rated using an a priori baseline score of 70/100 to establish inclusion. The initial search produced 52,847 articles, 63 of which were included in the qualitative synthesis. Thirteen articles met inclusion for nutrition: cafeteria interventions, single interventions, and vending interventions. Seventeen articles on physical activity were included: stair use, walking, and adjustable desks. For IEQ, 33 articles met inclusion: circadian disruption, view and natural light, and artificial light. A narrative synthesis was used to find meaningful connections across interventions with evidence contributing to health improvements. Commonalities throughout the nutrition studies included choice architecture, increasing the availability of healthy food items, and point-of-purchase food labeling. Interventions that promoted PA included stair use, sit/stand furniture, workplace exercise facilities and walking. Exposure to natural light and views of natural elements were found to increase PA and improve sleep quality. Overexposure to artificial light may cause circadian disruption, suppressing melatonin and increasing risks of cancers. Overall, design that encourages healthy behaviors may lower risks associated with chronic disease.
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