The American journal of medicine
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An increased incidence of thrombosis has been reported in patients with a prolonged activated partial thromboplastin time (APTT) due to a lupus anticoagulant (LA), which is an antibody to negatively charged phospholipids. The antiphospholipid antibodies can be quantitated in an enzyme-linked immunoabsorbent assay (ELISA) that utilizes cardiolipin as the antigen. With the development of the ELISA, two major areas of controversy have arisen. First, the correlation between assay results for LA and for the ELISA has varied widely among laboratories. Second, some investigators have described a correlation between high levels of anticardiolipin antibodies (ACA) and thrombotic disorders, whereas others have found no association between ACA levels and thrombosis in a general population of medical patients. To explore these issues further, the present study determined the sensitivity and specificity of an LA assay for detecting ACA in medical patients with a prolonged APTT. The association between the isotype and titer of ACA and thrombosis was examined in those patients positive for LA. ⋯ A test for LA in medical patients with a prolonged APTT can be sensitive and specific for ACA. Determination of ACA levels in patients who have LA that is not induced by medication or infection may define those patients at increased risk for thrombosis.
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Programmed stimulation, left ventricular ejection fraction, and signal-averaged electrocardiography were performed in patients with organic heart disease and spontaneous nonsustained ventricular tachycardia (VT) to determine the role of these techniques in risk stratification and management. ⋯ It is concluded that the signal-averaged ECG, ejection fraction, and programmed stimulation could be used for the risk stratification and management of patients with organic heart disease and nonsustained VT as follows: (1) Patients with no late potentials and with an ejection fraction of 40% or greater do not require invasive evaluation or antiarrhythmic therapy, since the incidences of induced VT and sudden death are very low. (2) Patients with late potentials as well as patients without late potentials but with an ejection fraction of less than 40% may be advised to undergo electrophysiologic evaluation.(ABSTRACT TRUNCATED AT 400 WORDS)
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We undertook this study to determine the occurrence of rhabdomyolysis in the hyperosmolal state. ⋯ Subclinical rhabdomyolysis is a common finding in the hyperosmolal state. Absence of hyperkalemia in the presence of muscle injury, hyperosmolality, hyperglycemia, and acidosis suggested pre-existing total-body potassium deficiency in many of these patients. In addition to hypokalemia, the hyperosmolal state predisposes to the development of rhabdomyolysis.
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Angiotensin-converting enzyme (ACE) inhibitors have been designed to reduce the generation of angiotensin II, i.e., to block the renin-angiotensin system. Interestingly, there exists a considerable dissociation between the time course of ACE inhibition and that of blockade of the renin-angiotensin system. Due to the greatly improved methodology used to estimate the degree of ACE inhibition in vitro and in vivo, it has become evident that the compensatory increase in renin levels in response to ACE inhibition is the key factor determining the degree and duration of blockade of the renin-angiotensin system resulting from ACE inhibition. A better understanding of these relationships would seem to be useful in determining duration of action and particularly the optimal dose of any ACE inhibitor.