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The extent of abnormality in patients with positive dobutamine echocardiography (DE) is predictive of risk, but the wall motion score (WMS) has low concordance among observers. We sought whether quantifying the extent of abnormal wall motion using tissue Doppler (TD) could guide risk assessment in patients with abnormal DE in 576 patients with known or(More)
Quantification of stress echocardiography may overcome the training requirements and subjective nature of visual wall motion score (WMS) assessment, but quantitative approaches may be difficult to apply and require significant time for image processing. The integral of long-axis myocardial velocity is displacement, which may be represented as a color map(More)
A very low drop voltage regulator that uses an NMOS output transistor, a start-up circuit and two voltage comparators, designed in a 0.12 /spl mu/m CMOS technology, is presented. By means of a charge pump to control the gate of the NMOS transistor it is possible to obtain the very low voltage drop, between input and output, of only 100 mV. A novel sample(More)
Echocardiographic analysis of regional left ventricular function is based upon the assessment of radial motion. Long-axis motion is an important contributor to overall function, but has been difficult to evaluate clinically until the recent development of tissue Doppler techniques. We sought to compare the standard visual assessment of radial motion with(More)
BACKGROUND Tissue Doppler may be used to quantify regional left ventricular function but is limited by segmental variation of longitudinal velocity from base to apex and free to septal walls. We sought to overcome this by developing a composite of longitudinal and radial velocities. METHODS AND RESULTS We examined 82 unselected patients undergoing a(More)
OBJECTIVE To determine whether HIV (Human Immunodeficiency Virus) antibody positive adults are capable of mounting an effective immune response when immunized with polyvalent pneumococcal vaccine. DESIGN 28 patients (nine homosexual men, one bisexual man, three heterosexual females, 10 injecting drug abusers, five haemophiliacs) and 11 healthy volunteers,(More)
The main limitation of dobutamine echocardiography (DE) is its subjective interpretation. We sought to reduce the need for expert interpretation by developing a quantitative approach to DE using myocardial Doppler velocity (MDV) in 242 patients undergoing DE. In 128 patients with a normal dobutamine echocardiogram, the normal range was designed to give a(More)
The risk of cardiac events in patients undergoing major noncardiac surgery is dependent on their clinical characteristics and the results of stress testing. The purpose of this study was to develop a composite approach to defining levels of risk and to examine whether different approaches to prophylaxis influenced this prediction of outcome. One hundred(More)
BACKGROUND Diastolic heart failure (DHF) is reported to account for 30-50% of heart failure presentations, but its prevalence in the absence of overt coronary disease is unclear. Diastolic heart failure is usually defined by exclusion (heart failure with normal left ventricular (LV) systolic function), and few studies have sought a specific diagnosis of(More)
BACKGROUND Although digital and videotaped images are known to be comparable for the evaluation of left ventricular function, their relative accuracy for assessment of more complex anatomy is unclear. We sought to compare reading time, storage costs, and concordance of video and digital interpretations across multiple observers and sites. METHODS One(More)