Stunned myocardium following coronary spasm.
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Coronary Angiography↗
Biomedical subjects
K Zamani
Publications and source records attributed to K Zamani.
Transcutaneous chemical collection of caffeine in normal subjects: relationship to area under the plasma concentration-time curve and sweat production.
A novel transcutaneous chemical collection device (TCD) has been developed to study the phenomenon of outward transcutaneous chemical migration. The TCD is a Bandaid-like device containing an immobilized aqueous media and binding reservoir material to prevent back-transfer into the skin. This device, when placed against the skin, allows collection and quantitation of chemicals that diffuse directly through the skin from within the body. The relationship of the amount of drug collected in the TCD to the amount in the body available for collection (as represented by the area under the plasma-concentration time curve, AUC) and the effects of sweating, a potential confounding factor, on collection of drug in a TCD were studied, using caffeine as a model compound. TCD were placed on the skin of normal male volunteers. Twenty-four hours later subjects took caffeine by mouth. Blood samples were collected and TCD were removed at various times after drug intake and analyzed by HPLC for caffeine. Studies of the sweating effect were carried out in a similar manner, except that one arm of each subject was maintained at 40 degrees C to induce local sweating, the other arm acted as a non-sweating control. The amount of caffeine collected was linearly related to the AUC. Sweating seemed to have a large (40%) contribution to transdermal collection in the early period (5.5 h) of the study, but this difference was much less (14%) at longer collection times (10 h).
Adult↗
[Coronary spasm and diffuse coronary vasoconstriction responsible for transient left ventricular insufficiency].
A 52 year old patient presenting with spontaneous anginal chest pain for 4 days was admitted to hospital for a more intense and prolonged chest pain associated with signs of left ventricular failure (gallop, pulmonary crepitations, hypoxemia). Coronary angiography showed marked septal hypokinesia and spontaneous localised spasm of the left anterior descending and marginal arteries with a variable degree of luminal narrowing of the other segments of these two arteries and of the right coronary artery. These changes regressed after intracoronary injection of molsidomine. The signs of left ventricular failure disappeared in 48 hours. The wall motion abnormality, monitored by 2D echocardiography, regressed slowly over 3 days. On the other hand, the electrocardiogram, which showed anterior wall subendocardial ischaemia with prolongation of the QTc interval during the spasm, remained abnormal for a long time. Therefore, in the absence of organic heart disease, coronary spasms associated with vasoconstriction can induce a sufficiently severe and durable alteration of left ventricular function to create clinical signs of cardiac failure and profound and prolonged ST-T wave changes on the electrocardiogram.
Coronary Angiography↗
Transcutaneous theophylline collection in preterm infants.
Transcutaneous collection of theophylline and its metabolite, caffeine, was undertaken in 33 preterm infants (2 to 89 days old) who were receiving routine theophylline therapy. Collection was done by means of a novel adhesive transcutaneous collection system. The transcutaneous collection system accumulated substances that migrated from the blood to the skin surface by trapping them in an activated charcoal-gel matrix. On one to three occasions, four transdermal collection systems were applied to the back or abdomen of each infant for 4 to 12 hours. During that time, blood samples were obtained for routine monitoring of plasma theophylline levels. Amounts of theophylline (95 +/- 198 ng) and caffeine (83 +/- 77 ng) in the transcutaneous collection system were significantly correlated with the respective average plasma drug concentration and postconceptional age (p less than 0.01). Skin reactions were limited to mild erythema. We concluded that theophylline and caffeine can be collected on the surface of the skin of preterm infants with a novel transcutaneous collection system. Amounts collected by means of the transcutaneous collection system correlated with plasma concentrations consistent with a diffusion process, but they were poor predictors of individual concentrations.
Age Factors↗
Transcutaneous collection of theophylline: constancy and linearity of skin permeability.
Transcutaneous chemical collection is a novel method for noninvasive collection and measurement of body exposure to chemicals using a transcutaneous collection device (TCD) consisting of a circular adhesive-tape-encased saline-activated carbon-aquagel patch. The objectives of this study were to determine (1) the time-course of skin permeability change after the placement of a TCD on the skin, and (2) the relationship between the amount of theophylline collected in a TCD and the amount of theophylline in the body as expressed by the area under the plasma concentration-time curve (AUC). Skin permeability changes were determined by emplacing TCDs (24/monkey) on the chests and abdomens of female rhesus monkeys (12 studies in 4 monkeys) at 48, 24, 6, 3 and 1 h prior to dosing with aminophylline (10 mg/kg of theophylline, i.v.) over 30 min. Several blood samples were collected, and TCDs were removed at 24 h post-dose; samples were assayed for theophylline by HPLC. The apparent permeability coefficients (Kp) increased following TCD placement reaching 90% of maximum by 17 h. The relationship between the amount of theophylline collected in the device (Q) and amount in the body over time was determined by emplacing TCDs on rhesus monkeys (8 studies in 4 monkeys) 24 h prior to administration of 10 mg/kg of theophylline. Qs from the TCDs removed at 0.17, 0.5, 1, 3, 6 and 24 h were linearly related to the plasma AUC according to the relationship: Q = (A x Kp) x AUC, where A is the area of gel in contact with the skin for each TCD.
Animals↗
Cigarette smoking during coronary angiography: diffuse or focal narrowing (spasm) of the coronary arteries in 13 patients with angina at rest and normal coronary angiograms.
To evaluate the acute effects of cigarette smoking on coronary arteries (CA), repeated coronary angiograms were performed in 13 patients with angina at rest and with normal coronary angiograms at basal state, during smoking, and then after methylergometrine (MEM) and after intracoronary nitroglycerin. Smoking induced anginal pain in three patients, triggered spasm (focal narrowing) in six, and/or an abnormal segmental diffuse narrowing (greater than 30%) in eight. The narrowing of the left CA was on average -21 +/- 13% (P less than 0.001), with more important narrowing of the mid-left anterior descending (-29 +/- 19%, P less than 0.001). The mean of the maximal segmental narrowing by patient was -34 +/- 13% (P less than 0.001). MEM produced similar effects and induced focal CA spasms in nearly the same patients at the same sites. Cigarette smoking may induce vasoconstrictive effects on CA in patients with rest angina and normal coronary angiograms. This action is not dose-dependent and may be initiated by less than one cigarette. These observations offer a new perspective for the understanding of the role of smoking in the precipitation of coronary events.
Adult↗
Terfenadine-ketoconazole interaction. Pharmacokinetic and electrocardiographic consequences.
OBJECTIVE: To examine prospectively the effects of ketoconazole on the pharmacokinetics and electrocardiographic repolarization pharmacodynamics (corrected QT intervals) of terfenadine in men and women. DESIGN: Prospective cohort study with each subject serving as his or her own control. SETTING: Outpatient cardiology clinic and inpatient telemetry unit for monitoring period. PARTICIPANTS: Six healthy volunteers (four men and two women, aged 24 to 35 years) not taking any prescription or over-the-counter medications. INTERVENTION: After achieving a steady state while taking terfenadine (60 mg every 12 hours for 7 days), daily concomitant oral ketoconazole (200 mg every 12 hours) was added to the subjects' regimen. Pharmacokinetic profiles were obtained while subjects were taking terfenadine alone and after the addition of ketoconazole. Electrocardiograms were obtained at baseline, after 1 week of taking terfenadine alone, and at the time of the second pharmacokinetic profile after the addition of ketoconazole to the regimen. MAIN OUTCOME MEASURES: Terfenadine and its acid metabolite serum concentrations and corrected QT intervals. RESULTS: All subjects had detectable levels of unmetabolized terfenadine after the addition of ketoconazole, which was associated with QT prolongation. Only two of the six subjects could complete the entire course of ketoconazole coadministration. Four subjects received a shortened duration of ketoconazole therapy because of significant electrocardiographic repolarization abnormalities. There was a significant change in the area under the curve of the acid metabolite of terfenadine after the addition of ketoconazole administration. CONCLUSIONS: Ketoconazole alters the metabolism of terfenadine in normal men and women and results in the accumulation of unmetabolized parent drug, which is associated with significant prolongation of the corrected QT interval. This drug combination should be avoided.
Adult↗