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Epicardial Coronary Arteries (epicardial + coronary_artery)

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Medical Sciences100%

Selected Abstracts

Vasodilator Stress Induces Infrequent Wall Thickening Abnormalities Compared to Perfusion Defects in Mild-to-Moderate Coronary Artery Disease: Implications for the Choice of Imaging Modality with Vasodilator Stress

ECHOCARDIOGRAPHY, Issue 4 2004
M.R.C.P., Ph.D., Prem Soman M.D.
Background: Experimental evidence suggests that although vasodilator stress agents consistently induce regional flow disparity between stenosed and normal coronary vascular beds, the occurrence of functional myocardial ischemia is infrequent, especially in mild-to-moderate coronary artery stenosis. Thus, it is hypothesized that dipyridamole infusion, even at high doses, will result in a disproportionately higher frequency of perfusion defects compared to regional wall thickening abnormalities. Methods: We performed simultaneous high-dose (0.84 mg/kg) dipyridamole stress echocardiography (Echo) and Tc-99m sestamibi SPECT (MIBI, methoxyisobutyl isonitrile) in 46 patients with coronary artery diameter stenosis >50% and ,90% in one or two epicardial coronary arteries, and no previous myocardial infarction. Results: Of a total of 828 segments, MIBI showed 97 reversible defects while Echo showed only 23 reversible wall thickening abnormalities. Of the 97 segments with reversible MIBI defects, only 13 (13%) showed simultaneous reversible wall thickening abnormalities during dipyridamole infusion. There were 24 patients with MIBI defects, of whom 10 (41%) showed a corresponding wall thickening abnormality. The sensitivity of MIBI and Echo for the detection of coronary artery disease was 52% and 21%, respectively (P = 0.001). Conclusion: This suggests that vasodilator stress is not optimally suited for use with techniques that use regional wall thickening abnormality as a marker of ischemia for the diagnosis of coronary artery disease. (ECHOCARDIOGRAPHY, Volume 21, May 2004) [source]

Abnormal Diastolic Flow Demonstrated by Color M Mode Echocardiography in Hypertrophic Cardiomyopathy with Mid-Ventricular Cavity Obliteration

ECHOCARDIOGRAPHY, Issue 1 2004
Timothy A. Mixon M.D.
We report a case of a 55-year-old woman who presented with ventricular tachycardia and myocardial infarction. Investigations revealed no disease of the epicardial coronary arteries, but a diagnosis of hypertrophic cardiomyopathy with mid-cavitary dynamic obstruction was made. Detailed echocardiographic examination, including pulse-wave Doppler and Color M Mode recordings revealed unusual components of diastolic dysfunction. (ECHOCARDIOGRAPHY, Volume 21, January 2004) [source]

Platelet function disorder in patients with coronary slow flow

CLINICAL CARDIOLOGY, Issue 3 2005
Dr. Mustafa Gökçe M.D.
Abstract Background: Some patients evaluated for chest pain with angiographically normal coronary arteries show coronary slow flow phenomenon (CSFP) on angiography. Slow flow of dye in epicardial coronary arteries is also not an infrequent finding in patients during routine coronary angiography. The precise pathophysiology of CSFP is not known yet. Hypothesis: This study investigates the presence of platelet function disorders in patients with CSFP. Methods: The patient group included 24 patients with CSFP detected by coronary angiography via the TIMI "frame count" method, and a control group included 23 patients with normal coronary flow. Platelet aggregability induced by use of ristocetin, collagen, and adenosine diphosphate (ADP), was measured from all blood samples in both control and patient groups. Results: The ratio of platelet aggregability increased significantly in patients with CSFP compared with patients with normal coronary flow (ristocetin 57.6 ± 15 vs. 45.4 ± 17.1, collagen 62.9 ± 16.4 vs. 48.9 ± 25.3, ADP 59.4 ± 18 vs. 42.4 ± 15.2, p < 0.05). Conclusion: Platelet aggregability is increased in patients with CSFP. [source]

Assessment of coronary blood flow and the reactivity of the microcirculation non-invasively with transthoracic echocardiography

CLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 3 2008
Tuomas Kiviniemi
Summary Background:, The development in ultrasound technology has allowed the use of non-invasive transthoracic echocardiography (TTE) for the study of coronary artery physiology and pathophysiology. TTE can be used to detect atherosclerotic changes in epicardial coronary arteries and to study the effects of specific interventions on coronary microcirculation. Aim:, The purpose of this review was to summarize the development of TTE, and outweigh the strenghts and weaknesses of the method for the evaluation of coronary artery blood flow. Moreover, findings from clinical trials studying microcirculatory reactivity using TTE are presented. Conclusions:, TTE is a feasible and reproducible method for the evaluation of coronary artery blood flow. It can also be used in assessing the vasodilation of the epicardial coronary artery simultaneously with flow velocity measurement during the cold pressor test and coronary flow velocity reserve assessment. It is specifically suitable for repeated measurements in interventional trials. [source]