Effects of time discrepancies between input and myocardial time-activity curves on estimates of regional myocardial perfusion with PET.

Unlabelled: Estimates of myocardial perfusion with PET using kinetic models require faithful recording of radioactivity content in blood and myocardium. Typically the arterial time-activity curve is obtained by placing a region of interest (ROIs) within the left atrial or left ventricular cavity. However, curves generated from these regions appear earlier in time than tissue time-activity curves obtained from ROIs within the myocardial tissue, and such time discrepancies can lead to errors in flow estimates.

The clinical utility of angioscopy during intracoronary stent implantation.

Angiographic evidence of thrombus may have important implications during coronary stent deployment procedures. The periprocedural presence of thrombus has been shown to increase the risk of subsequent stent thrombosis. Coronary angioscopy is a new technology that may prove more accurate for the detection of coronary thrombus.

Concordance of nutritive myocardial perfusion reserve and flow velocity reserve in conductance vessels in patients with chest pain with angiographically normal coronary arteries.

We have previously shown that myocardial perfusion can be quantified by positron emission tomography (PET) with 15O-labeled water (H2(15)O), as experimentally validated with radiolabeled microspheres in animal hearts. The purpose of our study was to determine whether myocardial nutritive perfusion reserve assessed with PET in human subjects was parallel to flow velocity reserve assessed in conductance vessels measured with intracoronary Doppler probes. We studied nine patients with chest pain and angiographically normal coronary arteries with intracoronary Doppler flow velocity assessments before and after administration of 16 micrograms of intracoronary adenosine.

Persistence of coronary vasodilator responsivity after cardiac transplantation.

Accelerated graft atherosclerosis is a major cause of death after cardiac transplantation. Although its detection currently requires surveillance angiography, loss of vasodilator responsivity may precede obstructive lesions and be detectable by noninvasive assessment of myocardial perfusion. Thirty-five allograft recipients were studied an average of 31 +/- 19 (mean +/- SD) months after transplantation.

Noninvasive delineation of the effects of moderate aging on myocardial perfusion.

Aging is accompanied by a decline in many aspects of cardiovascular function but little is known regarding its influence on myocardial perfusion. Eleven young adults (mean age 25 +/- 4 (s.d.