Comparison of myocardial contrast echocardiography derived myocardial perfusion reserve with invasive determination of coronary flow reserve.

Aims: Invasive measurements of coronary flow reserve (CFR) by Doppler flow wire are an established method for determining coronary blood flow physiology. Myocardial contrast echocardiography (MCE) is a potential non-invasive method for quantifying myocardial blood flow (MBF). However, few studies have compared MCE-derived myocardial perfusion reserve (MPR) with Doppler flow wire-derived CFR, measured simultaneously in human subjects.

Efficacy of atropine as a chronotropic agent in heart transplant patients undergoing dobutamine stress echocardiography.

Background: After heart transplant (HTX), the heart is completely denervated. While sympathetic reinnervation is likely to occur, there is conflicting evidence regarding parasympathetic reinnervation. Accordingly, it is unclear if atropine is efficacious as a chronotropic agent in HTX patients undergoing dobutamine stress echocardiography (DSE), since cholinergic cardiac stimulation is required for atropine to exert its effect.

Improved visualization of aortic intima-media thickening with the use of perflutren lipid microspheres.

Background: Transesophageal echocardiography (TEE) has been used to diagnose atherosclerotic disease for patients who present with systemic embolic events. The primary aim of this study was to assess the supplemental value of echocardiographic contrast to standard TEE in identifying the aortic intima-medial thickness.

Methods: An aorta phantom was used to validate the accuracy of border delineation with and without contrast during TEE imaging.

Lack of relation between imaging and physiology in ostial coronary artery narrowings.

This study compared ostial lesion angiographic severity with physiologic assessment and showed that, for diameter narrowings >70%, fractional flow reserves were >0.75 in 20 of 25 lesions and >0.75 in 30 of 30 lesions with <70% diameter narrowings.

Coronary hyperemic dose responses of intracoronary sodium nitroprusside.

Background: Sodium nitroprusside is one of several agents considered effective for treating the no-reflow phenomenon during acute coronary interventions. However, the coronary hyperemic dose responses and systemic hemodynamic effects of intracoronary nitroprusside have yet to be determined in humans. The purpose of this study was to compare the hyperemic and hemodynamic responses of intracoronary nitroprusside to intracoronary adenosine in patients during cardiac catheterization with angiographically normal anterior descending arteries.

Current concepts in coronary physiology for the interventionalist.

Coronary angiography remains the 'gold standard' for the diagnosis of epicardial coronary disease. However, precise quantification of stenosis severity is limited because of the complex three-dimensional geometry of epicardial plaques. To assist the angiographer in lesion assessment, several physiologic measurements have been developed to evaluate stenosis severity, including coronary flow reserve, relative coronary flow reserve and fractional flow reserve.