The American journal of emergency medicine
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Cardiovascular deterioration after seizures in tricyclic overdose has long been suspected. The investigators studied a patient with a nortriptyline HCI level of 1,205 ng/mL who had four generalized grand mal seizures, each lasting between 60 and 90 seconds that were immediately followed by hypotension requiring norepinephrine support. When the seizures were controlled with midazolam, the hypotension subsided and norepinephrine was decreased. The metabolic acidosis associated with the seizures may have caused hypotension by direct cardiotoxicity, an increase in bioavailability of tricyclic antidepressant because of changes in protein binding, an alteration of the effects of tricyclic antidepressant on cardiac membrane sodium channels, or a combination of these mechanisms.
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Using a hand scanner, radiographs were scanned into a personal computer (PC) for storage and viewing. These images were of superior or similar quality to x-ray photographs published in textbooks and journals. This represents a simple and inexpensive way for emergency physicians to store x-ray files electronically for instant access from a desktop or laptop computer. ⋯ Identical copies of the image files can be made and distributed for viewing on other PCs. The PC is a new tool that will improve our ability to organize our educational resource materials. Multimedia methods represent a new way to present and distribute audiovisual educational materials at a desktop.
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How bretylium tosylate affected the ventricular fibrillation threshold, electrophysiological parameters, and plasma catecholamine levels during hypothermia in dogs was studied. Threshold for ventricular fibrillation was determined by programmed electrical stimulation using a stimulation protocol that involved applying a maximum of five extrastimuli at body temperatures 37, 34, 31, 28, and 25 degrees C, and at the same temperatures during rewarming. Electrocardiogram, epicardial monophasic action potentials (MAP), and electrograms were recorded, and ventricular effective refractory period (VERP) was determined at each of the above temperatures. ⋯ BT had no effect on conduction velocity, and plasma catecholamine levels were not reduced. The antiarrhythmic effect of BT during hypothermia was attributed to an increased wavelength of refractoriness by its increase in the refractory period. This increased wavelength of refractoriness may prevent excitable gaps or increase circuit pathway in the setting of reentry arrhythmias.