PubMed · 8473647
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A M Lincoff, E J Topol. 1993. Trickle down thrombolysis.. https://doi.org/10.1016/0735-1097(93)90315-r
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Quantitative analysis of intracoronary ultrasound (ICUS) studies is performed on a series of tomographic cross-sectional ICUS images acquired during a motorized 0.5 mm/sec catheter pullback. Catheter displacement in the vascular lumen during the cardiac cycle causes an anatomically shuffled ICUS study, which results in a sawtooth-shaped appearance of the coronary segment in longitudinal reconstructed views in quantitative coronary ultrasound software packages. This hampers contour detection and leads to a laborious time-consuming semiquantitative analysis process that may produce inaccurate results. To solve these problems, in the past, online ECG-gated acquisition hardware has been applied. This article describes a novel image-based gating method called Intelligate, which features automatic retrospective selection of end-diastolic frames from videotaped or digitally stored ICUS studies. Our evaluation shows that there are no quantitative differences between analysis results of hardware ECG-gated and Intelligated ICUS studies.
BACKGROUND: Although harmonic imaging (HI) improves endocardial visualization and is necessary for myocardial perfusion imaging, it has yet to be implemented in transesophageal echocardiography. Our goal was to determine whether HI implemented in a prototype transesophageal echocardiography probe improved endocardial visualization and allowed perfusion imaging. METHODS: In 23 patients, fundamental and harmonic images were obtained in the transgastric short-axis (TSAX) and midesophageal 4-chamber views, and reviewed for endocardial visualization by 3 readers blinded to imaging mode. In 14 additional patients, perfusion imaging was performed in the TSAX view during contrast infusion. RESULTS: HI improved overall endocardial visualization, most noticeably in the anterior and lateral segments (P <.004) in the TSAX view, and in the lateral segments (P <.01) in the midesophageal 4-chamber view. The salvage rate was 8.3% in the TSAX view and 12.6% in the midesophageal 4-chamber view. Myocardial perfusion was consistently confirmed in the inferior (86%), posterior (100%), and lateral (79%) segments, but rarely in the septal (21%), anteroseptal (0%), and anterior (14%) segments. CONCLUSION: Use of HI with transesophageal echocardiography improves endorcardial visualization and allows partial assessment of myocardial perfusion.
We previously showed that hydrogen peroxide (H2O2) contributes to flow-induced dilation in human coronary resistance arteries (HCRAs); however, the source of this H2O2 is not known. We hypothesized that the H2O2 is derived from superoxide (O2*-) generated by mitochondrial respiration. HCRAs were dissected from right atrial appendages obtained from patients during cardiac surgery and cannulated with micropipettes. H2O2-derived radicals and O2*- were detected by electron spin resonance (ESR) using BMPO as the spin trap and by histofluorescence using hydroethidine (HE, 5 micromol/L) and dichlorodihydrofluorescein (DCFH, 5 micromol/L). Diameter changes to increases in pressure gradients (20 and 100 cm H2O) were examined in the absence and the presence of rotenone (1 micromol/L), myxothiazol (100 nmol/L), cyanide (1 micromol/L), mitochondrial complex I, III, and IV inhibitors, respectively, and apocynin (3 mmol/L), a NADPH oxidase inhibitor. At a pressure gradient of 100 cm H2O, ubisemiquinone and hydroxyl radicals were detected from effluents of vessels. Including superoxide dismutase and catalase in the perfusate reduced the ESR signals. Relative ethidium and DCFH fluorescence intensities in HCRAs exposed to flow were enhanced (1.45+/-0.15 and 1.57+/-0.12, respectively compared with no-flow) and were inhibited by rotenone (0.87+/-0.17 and 0.95+/-0.07). Videomicroscopic studies showed that rotenone and myxothiazol blocked flow-induced dilation (% max. dilation at 100 cm H2O: rotenone, 74+/-3% versus 3+/-13%; myxothiazol, 67+/-3% versus 28+/-4%; P<0.05). Neither cyanide nor apocynin altered flow-induced dilation. These results suggest that shear stress induced H2O2 formation, and flow-induced dilation is derived from O2*- originating from mitochondrial respiration.