From 1997 July to 2003 April at Hospital 108, the study was carried out on 90 patients suspected of ischemia with chest pain or on ECG. Ultrasound dobutamin stress test was undertaken with infused initial doses of 5mcg/kg/min until reaching an expected heart rate depending on the ages. Results showed that ultrasound dobutamin stresst test is a diagnostic method of 96% of sensitivity, 84% of specificity and 91% of accuracy
Myocardial Ischemia ; ultrasonography ; Heart Diseases

Dobutamin stress test with echocardiography was performed on 90 suspected patients of heart ischemia, aged 59.6  9.5 years old, during 29.1  17.49 months of following from July 1997 to April 2003 at the Hospital N0108. Results showed that, the procedure reach a sensitivity of 96%, specificity of 84% and an accuracy of 91%
Ultrasonography ; Myocardial Ischemia ; Heart Diseases

At the Department of internal neurology of Cho Ray Hospital from Dec 2000 to Jan 2003. 130 patients with acute hemisphere cerebral ischemic stroke were studied. Among them, 34 patients could not evaluated by transcranial Doppler sonography, only 79 had transcranial Doppler sonography (TDS) results and MRI results, which confirmed cerebral infarctus. TDS found 30 normal cases, 28 cases with asymmetric indices reduced, 18 cases increased, 1 case of localized acceleration, 2 cases of obstructive cerebral artery in the side of clinical symptom. MRI found 17 normal cases, 62 cases of stricture of cerebral arteries. Sensitivity and specificity of TDS accounted for 74.2% and 82.4% in comparing with cerebro-vascularogramme made by MRI.
Cerebrovascular Accident ; Brain Ischemia ; Cerebral Angiography ; Ultrasonography, Doppler, Transcranial

Intravenous tissue plasminogen activator (TPA) improves patient chances to recover from stroke by inducing mostly partial recanalization of large intracranial thrombi. TPA activity can be enhanced with ultrasound including 2 MHz transcranial Doppler (TCD). TCD identifies residual blood flow signals around thrombi, and, by delivering mechanical pressure waves, exposes more thrombus surface to circulating TPA. The international multi-center CLOTBUST trial showed that ultrasound enhances thrombolytic activity of a drug in humans thereby confirming multi-disciplinary experimental research conducted worldwide for the past 30 years. In the CLOTBUST trial, the dramatic clinical recovery from stroke coupled with complete recanalization within 2 hours after TPA bolus occurred in 25% of patients treated with TPA+TCD compared to 8% who received TPA alone (p=0.02). Complete clearance of a thrombus and dramatic recovery of brain functions during treatment are feasible goals for ultrasound-enhanced thrombolysis that can lead to sustained recovery. An early boost in brain perfusion seen in the Target CLOTBUST group resulted in a trend of 13% more patients achieving favorable outcome at 3 months, subject for a pivotal trial. However, different results were achieved in a small TRUMBI trial and another study that used Transcranial Color-Coded Duplex Sonography (TCCD). Adverse bio-effects of mid-KHz (300) ultrasound promote bleeding, including brain areas not-affected by ischemia while exposure to multi-frequency / multi-element duplex ultrasound resulted in a trend towards higher risk of hemorrhagic transformations. To further enhance the ability of TPA to break up thrombi, current ongoing clinical trials include phase II studies of a single beam 2 MHz TCD with perflutren-lipid microspheres. Enhancement of intra-arterial TPA delivery is being clinically tested with 1.7-2.1 MHz pulsed wave ultrasound (EKOS catheter). Multi-national dose escalation studies of microspheres and the development of an operator independent ultrasound device are underway.
Brain ; Brain Ischemia* ; Hemorrhage ; Humans ; Ischemia ; Microspheres ; Perfusion ; Stroke ; Thrombosis ; Tissue Plasminogen Activator ; Ultrasonography*

Spontaneous coronary artery dissection (SCAD) is an uncommon cause of acute myocardial ischemia, which frequently presents as sudden death. The pathophysiology and treatment of SCAD have not been fully determined. Herein, a case of SCAD, manifesting as variant angina, which rapidly progressed during an ergonovine test, in which 3 drug-eluting stents were deployed using intravascular an ultrasound guidance, with an excellent immediate result, is reported.
Coronary Vessels* ; Death, Sudden ; Drug-Eluting Stents ; Ergonovine* ; Myocardial Ischemia ; Stents* ; Ultrasonography* ; Ultrasonography, Interventional

Treatment strategies for patients with coronary artery disease (CAD) should be based on objective evidence of inducible ischemia in the subtended myocardium to improve clinical outcomes, symptoms, and cost-effectiveness. Fractional flow reserve (FFR) is the most verified index to-date for invasively evaluating lesion-specific myocardial ischemia. Favorable results from large clinical trials that applied FFR-guided percutaneous coronary intervention (PCI) prompted changes in coronary revascularization guidelines to emphasize the importance of this ischemia-based strategy using invasive coronary physiology. However, the frequency of functional evaluations is lacking in daily practice, and visual assessment still dominates treatment decisions in CAD patients. Despite recent efforts to integrate functional and anatomical assessments for coronary stenosis, there is considerable discordance between the 2 modalities, and the diagnostic accuracy of simple parameters obtained from current imaging tools is not satisfactory to determine functional significance. Although evidence that supports or justifies anatomy-guided PCI is more limited, and FFR-guided PCI is currently recommended, it is important to be aware of conditions and factors that influence FFR for accurate interpretation and application. In this article, we review the limitations of the current anatomy-derived evaluation of the functional significance of coronary stenosis, detail considerations for the clinical utility of FFR, and discuss the importance of an integrated physiologic approach to determine treatment strategies for CAD patients.
Coronary Angiography ; Coronary Artery Disease ; Coronary Stenosis ; Humans ; Ischemia ; Myocardial Ischemia ; Myocardium ; Percutaneous Coronary Intervention ; Physiology ; Ultrasonography, Interventional

This study evaluated the application of quantitative tissue velocity imaging (QTVI) in assessing regional myocardial systolic and diastolic functions in dogs with acute subendocardial ischemia. Animal models of subendocardial ischemia were established by injecting microspheres (about 300 microm in diameter) into the proximal end of left circumflex coronary artery in 11 hybrid dogs through cannulation. Before and after embolization, two-dimensional echocardiography, QTVI and real-time myocardial contrast echocardiography (RT-MCE) via intravenous infusion of self-made microbubbles, were performed, respectively. The systolic segmental wall thickening and subendocardial myocardial longitudinal velocities of risk segments before and after embolization were compared by using paired t analysis. The regional myocardial video intensity versus contrast time could be fitted to an exponential function: y=A.(1-exp(-beta.t)), in which the product of A and beta provides a measure of myocardial blood flow. RT-MCE showed that subendocardial normalized A.beta was decreased markedly from 0.99+/-0.19 to 0.35+/-0.11 (P<0.05) in 28 left ventricular (LV) myocardial segments after embolization, including 6 basal and 9 middle segments of lateral wall (LW), 8 middle segments of posterior wall (PW) and 5 middle segments of inferior wall (IW). However, there was no statistically significant difference in subepicardial layer before and after embolization. Accordingly, the ratio of A.beta of subendocardial myocardium to subepicardial myocardium in these segments was significantly decreased from 1.10+/-0.10 to 0.31+/-0.07 (P<0.05). Although the systolic wall thickening did not change 5 min after the embolization in these ischemic segments (29%+/-3% vs 31%+/-5%, P>0.05), the longitudinal peak systolic velocities (Vs) and early-diastolic peak velocities (Ve) recorded by QTVI were declined significantly (P<0.05). Moreover, the subendocardial velocity curves during isovolumic relaxation predominantly showed positive waves, whereas they mainly showed negative waves before the embolization. This study demonstrates that QTVI can more sensitively and accurately detect abnormal regional myocardial function and post-systolic systole caused by acute subendocardial ischemia.
Contrast Media ; Echocardiography/*methods ; Endocardium/physiopathology ; Microbubbles ; Myocardial Contraction/physiology ; Myocardial Ischemia/etiology ; Myocardial Ischemia/*physiopathology ; Myocardial Ischemia/*ultrasonography ; Myocardium/pathology ; Ventricular Function, Left/*physiology

PURPOSE: We wanted to determine the incidence and characteristics of failing graft after implantation of autologous reversed vein grafts. METHOD: From Sep. 2003 to Dec. 2005, 84 leg bypasses using autologous reversed vein grafts were performed for chronic leg ischemia in 75 patients. After the operations, duplex ultrasonography (DUS) and measurement of the ankle brachial index (ABI) were performed every 3 months for the purpose of examining the graft patency. The criteria for a failing graft was a peak systolic velocity (PSV) of the stenotic lesion >300 cm/s, or a PSV distal to the occlusive lesion <40 cm/s, but with sustained patency of the vein graft. We investigated the timing of detection, the site of the causative lesion, and the clinical symptoms of the failing grafts. For the treatment of failing grafts, surgeries (vein patch, graft extension, or inflow artery reconstruction) were performed in 4 legs. The Kaplan Meier method was used for calculating the rate of graft patency. RESULT: Nine failing grafts were detected by DUS in 8 patients. The sites of causative lesions were the inflow artery (2), the proximal anastomosis (6), and the distal anastomosis (1). Seven of the 9 patients with failing grafts were asymptomatic, 1 patient had claudication and another patient suffered from resting pain of the involved leg. The assisted graft primary patency rates at 1 and 2 years after operations were 86% and 53%, respectively. CONCLUSION: Nine cases of failing grafts were detected during surveillance with duplex ultrasonography after implantation of autologous reversed vein grafts.
Ankle Brachial Index ; Arteries ; Diagnosis* ; Humans ; Incidence ; Ischemia ; Leg ; Lower Extremity* ; Transplants* ; Ultrasonography ; Veins

PURPOSE: Alterations in cerebral blood flow are very important for understanding the neurological consequences of all varieties of perinatal asphyxia. The purpose of this study is to measure the change of cerebral blood flow velocity and resistance index (RI) of middle cerebral artery (MCA) according to the time in asphyxiated infants. METHODS: We studied 7 asphyxiated term infant and 27 normal term infant who were born at Ewha Womans University Hospital from January 1996 to August 1997. Using the Doppler ultrasound, we examined blood flow velocity and RI of the middle cerebral artery. RESULTS: Clinical characteristics were not significantly different in both groups. Peak systolic flow velocity (PSFV) in asphyxiated infants significantly decreased than control (P<0.05). End diastolic flow velocity (EDFV) was not significantly different in both groups. RI in asphyxiated infants significantly decreased for 24 hours (P<0.05). No control infant ever had a RI value of 0.55 or below, three (42.9%) asphyxiated infants had a RI value of 0.55 or below. The changes of the systemic BP and heart rate were not significant. Two (28.6%) asphyxiated infants were proven periventricular white matter ischemia by ultrasonography. CONCLUSION: It is therefore very important to monitor RI in asphyxiated infants even if the degree of asphyxia is mild.
Asphyxia ; Blood Flow Velocity* ; Female ; Heart Rate ; Humans ; Infant* ; Ischemia ; Middle Cerebral Artery ; Ultrasonography

PURPOSE: Alterations in cerebral blood flow are very important for understanding the neurological consequences of all varieties of perinatal asphyxia. The purpose of this study is to measure the change of cerebral blood flow velocity and resistance index (RI) of middle cerebral artery (MCA) according to the time in asphyxiated infants. METHODS: We studied 7 asphyxiated term infant and 27 normal term infant who were born at Ewha Womans University Hospital from January 1996 to August 1997. Using the Doppler ultrasound, we examined blood flow velocity and RI of the middle cerebral artery. RESULTS: Clinical characteristics were not significantly different in both groups. Peak systolic flow velocity (PSFV) in asphyxiated infants significantly decreased than control (P<0.05). End diastolic flow velocity (EDFV) was not significantly different in both groups. RI in asphyxiated infants significantly decreased for 24 hours (P<0.05). No control infant ever had a RI value of 0.55 or below, three (42.9%) asphyxiated infants had a RI value of 0.55 or below. The changes of the systemic BP and heart rate were not significant. Two (28.6%) asphyxiated infants were proven periventricular white matter ischemia by ultrasonography. CONCLUSION: It is therefore very important to monitor RI in asphyxiated infants even if the degree of asphyxia is mild.
Asphyxia ; Blood Flow Velocity* ; Female ; Heart Rate ; Humans ; Infant* ; Ischemia ; Middle Cerebral Artery ; Ultrasonography