Myocardial Scintigraphy (myocardial + scintigraphy)

Distribution by Scientific Domains
Distribution within Medical Sciences

Selected Abstracts

Exercise-Attenuation of Q-Waves in II, III, and aVF, and R-Waves in V1 and V2 in a Patient with an Inferior Infarction and Anterior Wall Ischemia

A 63-year-old male patient with inferior infarction revealed transient attenuation of the Q-waves in II, III, and aVF, and R-waves in V1,V3 during an exercise stress test. Myocardial scintigraphy disclosed ischemia of the anterior wall and coronary arteriography, a 90% stenosis of the left main coronary artery (LMCA). The mechanism involved appears to be a transient failure of the anterior wall to generate adequate depolarization forces for the genesis of Q-waves in the inferior leads and R-waves in the anterior leads. This electrocardiogram sign is diagnostic of severe anterior wall ischemia due to left anterior descending or LMCA stenosis. [source]

Identification of Hemodynamically Significant Restenosis after Percutaneous Transluminal Coronary Angioplasty in Acute Myocardial Infarction by Transesophageal Dobutamine Stress Echocardiography and Comparison with Myocardial Single Photon Emission Computed Tomography

Background: Beside thrombolysis, percutaneous transluminal coronary angioplasty (PTCA) has become a well-established treatment for acute myocardial infarction. However, restenosis occurs in approximately 15%-40 % of patients. Despite a frequently occurring infarct-related regional systolic dysfunction at rest, the identification of hemodynamically relevant restenosis seems important in terms of risk stratification, adequate treatment, and possible improvement of prognosis in these patients. This study was designed to assess the role of transesophageal dobutamine stress echocardiography and myocardial scintigraphy for identification of hemodynamically significant restenosis after PTCA for acute myocardial infarction. Methods: Multiplane transesophageal stress echocardiography (dobutamine 5, 10, 20, 30, and 40 ,g/kg per min) studies and myocardial single photon emission computed tomography (SPECT) studies were performed in 40 patients, all of whom underwent PTCA in the setting of acute myocardial infarction , 4 months prior to the test. Repeated coronary angiography was performed in all study patients who showed stress-induced perfusion defects or wall-motion abnormalities, or both. Results: Significant restenosis (, 50%) was angiographically found in 15 (37.5%) of 40 patients. Of these 15 patients, transesophageal dobutamine stress echocardiography identified restenosis in 12 (80%) and myocardial SPECT in 14 (93%), yielding diagnostic agreement in 70% of patients. Echocardiographic detection of restenosis was based mainly on a biphasic response to increasing doses of dobutamine. Sensitivity and specificity for identification of hemodynamically relevant restenosis in individual patients was 80% and 92%, respectively for dobutamine stress echocardiography versus 93% and 68% for myocardial SPECT. Conclusions: Both transesophageal dobutamine stress echocardiography and myocardial SPECT were highly sensitive in identifying significant restenosis after PTCA for acute myocardial infarction. Therefore, either test, as a single diagnostic tool or especially if performed together, are clinically valuable alternatives to coronary angiography for the detection of restenosis after PTCA for acute myocardial infarction. [source]

Cardiac 123I-MIBG scintigraphy in patients with essential tremor

Phil Hyu Lee MD
Abstract In some cases, it is difficult to differentiate essential tremor (ET) from Parkinson's disease (PD), especially in the early stages of the disease. We investigated cardiac sympathetic dysfunction using 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy in 22 patients with ET, in comparison with early PD and tremor-dominant PD (TDPD). The mean ratio of 123I-MIBG uptake in the region of interest in the heart to that in the mediastinum (H/M ratio) was significantly greater in patients with ET (1.99 0.21) than in those with either TDPD (1.28 0.11) or early PD (1.28 0.17; each P < 0.001). The H/M ratio in all patients with ET was greater than two standard deviations above the range of the ratio in the patients with early PD or TDPD. 2006 Movement Disorder Society [source]

Dobutamine stress surface mapping of myocardial ischemia in Kawasaki disease

Nobuyuki Takechi
Abstract Background: To detect and localize myocardial ischemia, a method that does not require physical exertion is sometimes needed in children with Kawasaki disease. Methods: Dobutamine stress body surface mapping was performed in 115 children with a history of Kawasaki disease (58 without coronary artery lesions, 40 who had coronary lesions without myocardial ischemia and 17 with myocardial ischemia). The maximum infusion rate of dobutamine was 30 ,g/kg per min. Myocardial ischemia was diagnosed by the presence of an area of hypoperfusion on scintigraphy at rest and/or an increase in hypoperfusion during a dobutamine stress test compared with resting scintigraphy. We studied the number of leads that showed significant ST depression on the isopotential map (nST), the number of the row containing the lead with the smallest negative value on the isointegral map (Imin), and the localization of myocardial ischemia on the isointegral map. Based on findings in patients without coronary artery lesions, we defined the criteria for detecting myocardial ischemia as nST , 1 and Imin, 4. Results: The sensitivity of detecting myocardial ischemia was 94.1% using nST and 41.7% using Imin, while the specificity of these methods was 98.9 and 96.9%, respectively. The localization of myocardial ischemia on stress body surface mapping was 100% concordant with that determined by stress myocardial scintigraphy. Conclusions: Dobutamine stress body surface mapping for the detection of myocardial ischemia is a non-invasive, more convenient and repeatable test compared with exercise myocardial scintigraphy and it is a more objective test compared with exercise echocardiography. Dobutamine stress body surface mapping is useful for the identification and localization of silent myocardial ischemia in pediatric patients with Kawasaki disease, especially those who cannot perform tests involving physical exercise. [source]

Decreased ventilatory response to hypercapnia in dementia with Lewy bodies,

Katsuyoshi Mizukami MD
A systematic autonomic dysfunction observed among patients with dementia with Lewy bodies (DLB) has recently attracted close attention. Here, we compare cardiovascular and pulmonary autonomic functions among patients with DLB, patients with Alzheimer's disease, and healthy control subjects. All 15 DLB patients demonstrated severely low ventilatory response to hypercapnia, whereas none of the other subjects demonstrated abnormal results. The majority of the DLB patients showed impaired heart rate variability, low uptake on 123I-metaiodobenzylguanidine myocardial scintigraphy, and orthostatic hypotension. Ventilatory response to hypercapnia as a marker of respiratory autonomic function is a promising diagnostic tool for DLB. Ann Neurol 2009;65:614,617 [source]