Exercise echocardiography vs exercise SPECT testing.
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Coronary Disease↗
Biomedical subjects
C Z Dickinson
Publications and source records attributed to C Z Dickinson.
Clinical outcome of patients evaluated with emergency centre myocardial perfusion SPET for unexplained chest pain.
The clinical outcome of 68 patients with unexplained chest pain triaged with emergency centre (EC) SPET myocardial perfusion imaging (MPI) was assessed at 9 month follow-up. Based on clinical presentation and EC-MPI, 63% (43/68) of patients were discharged from the EC; 84% (36/43) of these patients reported no further symptoms at follow-up. There were no adverse clinical events in patients with totally normal EC-MPI.
Chest Pain↗
Cost-effectiveness of myocardial perfusion imaging with SPECT in the emergency department evaluation of patients with unexplained chest pain.
PURPOSE: To determine the cost-effectiveness of promptly performing myocardial perfusion (MP) imaging with single photon emission computed tomography (SPECT) in patients presenting to the emergency department with unexplained chest pain. MATERIALS AND METHODS: Fifty patients with unexplained chest pain underwent MP imaging with SPECT and technetium-99m sestamibi. The cardiologists' management plans before and after receipt of imaging findings were compared. Costs were determined from analysis of comparable admissions for the 6 months before the start of the study. RESULTS: The cardiologists' confidence in their clinical diagnosis significantly increased with use of MP imaging (P<.0001). MP imaging results altered management decisions in 34 patients. Twenty-nine patients were sent home on the basis of imaging findings. None of the patients with a normal MP image experienced a serious adverse cardiac event. The total savings to the hospital was $39,296, or $786 per patient. CONCLUSION: Performing MP imaging in patients with unexplained chest pain while in the emergency department is cost-effective.
Adenosine↗
Effects of Na-K-2Cl cotransport inhibition on myocardial Na and Ca during ischemia and reperfusion.
In the context of the "pump-leak" hypothesis (37), changes in myocardial intracellular Na (Nai) during ischemia and reperfusion have historically been interpreted to be the result of changes in Na efflux via the Na-K pump. We investigated the alternative hypothesis that changes in Nai during ischemia are the result of changes in the Na "leak" rather than changes in the pump. More specifically, we hypothesize that the increase in Nai during ischemia is in part the result of increased Na uptake mediated by Na/H exchange. Furthermore, we present data consistent with the interpretation that the Na-K-2Cl cotransporter is active (or, alternatively, displaced from equilibrium) during ischemia and may contribute an additional Na efflux pathway during reperfusion. Thus inhibition of Na efflux via Na-K-2Cl cotransport during ischemia and reperfusion could result in increased Nai and therefore decreased force driving Ca efflux via Na/Ca exchange and ultimately increased intracellular Ca concentration ([Ca]i). Nai (in meq/kg dry wt) and [Ca]i (in nM) were measured in isolated Langendorff-perfused rabbit hearts using nuclear magnetic resonance spectroscopy. Except, during the 65 min of ischemia, hearts were perfused with N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid-buffered Krebs-Henseleit solution equilibrated with 100% O2 at 23 degrees C and pH 7.4 +/- 0.05. During ischemia, Nai rose from 16.6 +/- 0.3 to 62.9 +/- 5.1 (delta Nai approximately 46) meq/kg dry wt and decreased during subsequent reperfusion (mean +/- SE, n = 3 hearts). To measure Na uptake ("leak") in the absence of efflux via the Na-K pump, in all of the protocols described below, the perfusate was nominally K-free solution containing 1 mM ouabain for 10 min before ischemia and during the 30-min reperfusion. After K-free perfusion, Nai rose from 20.2 +/- 0.5 to 79.1 +/- 5.3 (delta Nai approximately 59) meq/kg dry wt (n = 3) during ischemia and decreased during K-free reperfusion. When amiloride (1 mM) was added to the K-free perfusate to inhibit Na/H exchange, Nai rose from 16.3 +/- 0.9 to 44.7 +/- 5.1 (delta Nai approximately 28) meq/kg dry wt (n = 3) during ischemia; i.e., amiloride decreased Na uptake. When bumetanide (20 microM) was added to the nominally K-free perfusate to inhibit Na-K-2Cl contransport, Nai rose from 22.5 +/- 3.9 to 83.8 +/- 13.9 (delta Nai approximately 61 meq/kg dry wt (n = 3) during ischemia and did not decrease during reperfusion; i.e., bumetanide inhibited Na recovery during reperfusion (P < 0.05 compared with bumetanide free). For the same protocol, the presence of bumetanide resulted in increased [Ca]i during ischemia and reperfusion (P < 0.05); these increases in [Ca]i are interpreted to be the result of increased Nai. Thus the results are consistent with the hypotheses.
Animals↗
Cervical lymph node metastasis of thyroid papillary carcinoma imaged with fluorine-18-FDG, technetium-99m-pertechnetate and iodine-131-sodium iodide.
A 49-yr-old white woman with diffuse sclerosing variant of papillary carcinoma of the thyroid revealed abnormal [18F]FDG accumulation within cervical lymph node metastases prior to thyroidectomy. The abnormal cervical foci of glucose metabolism corresponded to similar areas of abnormal [99mTc]pertechnetate and radioiodine accumulation on presurgical scans. The primary thyroid tumor within the thyroid gland was not delineated as a focal defect on any of the three imaging studies. The relative thyroid-to-background soft-tissue ratio in the [18F]FDG study, however, appeared higher than usual. As with 131I and [99mTc]pertechnetate, this case demonstrates that [18F]FDG PET can detect cervical lymph node metastases in the preoperative thyroid cancer patient.
Carcinoma, Papillary↗
Pseudoaneurysm of the left ventricle. Diagnosis by first pass scintigraphy.
False aneurysm of the left ventricle is a rare complication of myocardial infarction with a high propensity for late rupture. Timely diagnosis is important and surgical repair is curative in a high percentage of patients. A case in which a false left ventricular aneurysm was recognized by first pass radionuclide angiography and confirmed by contrast ventriculography is reported. Surgery was then performed successfully. The diagnosis of false left ventricular aneurysm using radionuclide angiography, as well as other diagnostic imaging modalities, is discussed.
Heart Aneurysm↗
Congenital absence of the gallbladder: another cause of false-positive hepatobiliary image.
Hepatobiliary imaging with the various technetium-labeled IDA compounds is more than 90% sensitive and specific for the diagnosis of acute cholecystitis. Causes of false-positive studies include chronic cholecystitis, cystic-duct obstruction by tumor, prolonged fasting, the nonfasting state, pancreatitis, alcoholism, parenteral hyperalimentation, and severe intercurrent illness. A case of congenital absence of the gallbladder is submitted as another cause of a false-positive scan.
Aged↗