Texas Heart Institute journal
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Inferior vena cava filters are often used as alternatives to anticoagulant therapy for the prevention of pulmonary embolism. Many of the clinical data that support the use of these devices stem from relatively limited retrospective studies. The dual purpose of this review is to examine the incidence of thrombotic complications associated with inferior vena cava filters and to discuss the role of anticoagulant therapy concurrent with filter placement. Device-associated morbidity and overall efficacy can be considered only in the context of rates of vena cava thrombosis, insertion-site thrombosis, recurrent deep venous thrombosis, and recurrent pulmonary embolism.
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Review Biography Historical Article
The discovery of aspirin's antithrombotic effects.
Aspirin has long been established as a useful analgesic and antipyretic. Even in ancient times, salicylate-containing plants such as the willow were commonly used to relieve pain and fever. In the 20th century, scientists discovered many details of aspirin's anti-inflammatory and analgesic properties, including its molecular mechanism of action. ⋯ We present Craven's story, which demonstrates the value of a single physician's commitment to lifelong learning. In addition, we summarize the work of the physicians and scientists who discovered the molecular mechanisms by which aspirin exerts its antiplatelet effects. Collectively, these discoveries exemplify the complementary roles of basic science and clinical observation in advancing medicine.
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Cardiac anesthesiologists have the responsibility to detect myocardial ischemia in a timely manner, which can be a challenging task in the perioperative environment. Transesophageal echocardiography pulmonary artery catheterization, and electrocardiography are the 3 major methods available for monitoring perioperative ischemia. Echocardiography, the newest and most sophisticated method, has been shown to be highly sensitive for detecting ischemia associated with systolic dysfunction. ⋯ Pulmonary artery catheterization can provide information about systolic dysfunction, diastolic dysfunction, and mitral regurgitation, but the sensitivity and safety of catheterization have been questioned. Electrocardiography can be a superb monitoring device as long as clinicians pay adequate attention to lead selection and placement, filter selection, and gain adjustment. The optimal monitoring approach should integrate all 3 available monitoring systems in order to increase the likelihood of detecting both supply- and demand-mediated ischemia.
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The major therapeutic approach to systemic and pulmonary hypertension and vasospasm in cardiac surgery patients involves the use of parenteral agents that reverse systemic vasoconstriction and produce vasodilation. Potential pharmacologic approaches include 1) alpha1-adrenergic receptor blockers, ganglionic blockers, and calcium channel blockers; 2) central alpha2-adrenergic receptor agonists, dopamine1-adrenergic receptor agonists, potassium channel modulators, and vascular cyclic nucleotide stimulators; 3) phosphodiesterase enzyme inhibitors, and 4) angiotensin-converting enzyme inhibitors. Of the currently available intravenous vasoactive therapies, the mainstay agents are the nitrovasodilators and the dihydropyridine-type calcium channel blockers. ⋯ Intravenous dihydropyridine-type calcium channel blockers inhibit mechanical responses of cardiac muscle and vascular smooth muscle by blocking inward calcium currents. Nicardipine is an arterial specific vasodilator. Treatment for vasospasm is usually empiric; pharmacologic options include nitroglycerin, but dihydropyridine calcium channel blockers and phosphodiesterase inhibitors should also be considered.
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Cryptogenic stroke is a diagnosis of exclusion. These are strokes that occur in people who are usually less than 55 years old, without an identifiable cause. Our sensitivity to these events has been heightened because of the new definitions of a transient ischemic attack. ⋯ They also frequently have PFOs; if you close the PFO, the arterial desaturation is alleviated. Fat emboli during orthopedic surgery or air emboli during neurosurgery may also travel through the venous system. If you don't have a PFO, the fat or the air is trapped in the lungs and doesn't cause much of a problem unless it's massive; but if you have a PFO, then the embolus can go from right to left atrium up to the brain, with devastating neurologic consequences.