Kentaro Ueda

Impaired coronary microvascular endothelial function in men with metabolic syndrome

AIM To assess coronary endothelial function of conduit and resistance vessels in patients with metabolic syndrome (MS). METHODS Seventy-eight men (mean age, 57 years) with chest pain and angiographically normal coronary arteries were included in the study. Patients with coronary spastic angina were excluded. Changes in coronary artery diameter and coronary blood flow (CBF) in response to acetylcholine (ACh) were determined using quantitative coronary angiography and Doppler velocity measurements. Coronary flow reserve was calculated as the ratio of coronary blood velocity after adenosine triphosphate infusion relative to baseline values. Patients were divided into two groups based on the presence or absence of MS. RESULTS There were 24 patients in the MS group (31%). The increase in CBF in response to ACh infusion was impaired in the MS group (P < 0.0001) compared to the non-MS group, whereas changes in coronary artery diameter in response to ACh infusion did not differ between the two groups. Multivariate regression analysis revealed that MS was a significant factor associated with the lesser change in CBF induced by ACh infusion at 30 μg/min (P < 0.0001, r(2) = 0.46). CONCLUSION Coronary endothelial dysfunction was present at the level of resistance vessels but not conduit vessels in the MS patients included in our study.

Clinical impact of dyslipidemia for coronary plaque vulnerability in acute coronary syndrome without metabolic syndrome.

BACKGROUND Although the metabolic syndrome is associated with incident cardiovascular disease, low-density lipoprotein (LDL) cholesterol is a well-known risk factor for coronary atherosclerosis. The aim of this study was to clarify the clinical markers for coronary plaque vulnerability in acute coronary syndrome (ACS) patients (men) without the metabolic syndrome. METHODS Consecutive Japanese men with ACS (n=264) underwent emergent coronary angiography and B-mode carotid ultrasonography. Common carotid intima-media thickening and vascular dilatation were considered to indicate carotid artery remodeling. Patients were divided into two groups based on the number of complex plaques identified by coronary angiography. RESULTS Abdominal obesity and low high-density lipoprotein cholesterol levels were frequently observed in overall patients with multiple complex coronary lesions. Although the metabolic syndrome was a significant independent predictor of multiple complex coronary lesions in overall ACS patients, a high LDL cholesterol level was an independent predictor in ACS patients without the metabolic syndrome. Carotid artery remodeling was an independent predictor of multiple complex coronary lesions in both overall patients and patients without the metabolic syndrome. CONCLUSION In ACS patients without the metabolic syndrome, high LDL cholesterol levels and carotid artery remodeling are important indicators for assessing the efficacy of aggressive treatments for secondary prevention of ACS.

Adrenomedullin causes coronary vasodilation in humans: effects of inhibition of nitric oxide synthesis.

Experimental studies have shown that adrenomedullin (AM) causes vasodilation, in part, mediated by endothelium-derived nitric oxide (NO). However, it remains to be clarified how NO is involved in AM-induced coronary vasoreactivity in humans. We examined whether NO contributes to the vasodilatory effects of adrenomedullin on human coronary arteries. In 10 patients with angiographically normal coronary arteries, adrenomedullin (low dose: 1 ng/kg/min; high dose: 10 ng/kg/min) was infused into the left coronary ostium before and after an infusion of NG-monomethyl-L-arginine (L-NMMA, 40 μmol/min for 5 min), an NO synthase inhibitor. Coronary diameter and coronary blood flow (CBF) were evaluated by quantitative angiography and Doppler flow velocity measurements. Changes in these parameters in response to adrenomedullin were expressed as percent changes from baseline values. Adrenomedullin at a high dose dilated coronary arteries (3.7 ± 0.5%, P < 0.001). Adrenomedullin increased the coronary blood flow at both doses (low: 55.7 ± 13.9%, P < 0.01; high: 48.8 ± 9.8%, P < 0.001). After the infusion of L-NMMA, adrenomedullin-induced coronary vasodilation and increase in coronary blood flow were attenuated. These findings suggest that adrenomedullin dilates human coronary arteries through an increase in NO production, at least in part.

Coronary Vasospasm Produces Reversible Perfusion Defects Observed During Adenosine Triphosphate Stress Myocardial Single‐photon Emission Computed Tomography

Adenosine triphosphate stress thallium‐201 single‐photon emission computed tomography (ATP‐SPECT) is useful for diagnosing coronary artery disease (CAD), although sometimes false positive results are observed. It has not been established whether a coronary spasm is responsible for the false positive findings during ATP‐SPECT.

Usefulness of directional coronary atherectomy in patients with acute anterior myocardial infarction

To assess the usefulness of directional coronary atherectomy (DCA) in acute myocardial infarction (AMI), 139 consecutive patients with anterior wall AMI undergoing successful catheter intervention were studied. The reocclusion rate was significantly lower in the last 70 patients who underwent DCA as aggressively as possible compared with the first 69 patients treated with coronary balloon angioplasty (12.1% vs 3.0%, p <0.05).

Retrieving the movement of multiple objects based on spatiotemporal abstraction

Content based retrieval of video data based on the movement of objects is one of the method in addition to those based on image features such as color, shape, and/or texture. Most of the studies, which aimed at retrieving the movement of objects, concentrate on evaluating individual movement of objects. However, this strategy is not always effective especially in case where multiple objects are in motion, and the interest of retrieval lies in the movement of multiple objects as a cluster. This paper proposes a framework of modeling abstract movement of multiple objects based on the idea of group. The movement of individual object is extracted first, and the movement is aggregated based on a specified spatiotemporal granularity. A query is evaluated for the aggregated movement of multiple objects instead of individual movement of objects. We applied this framework for analyzing the aggregated flow of soccer games as an example.

The differences between posteroseptal and the other atrioventricular accessory pathways: the coronary sinus morphology and the conduction over accessory pathways

62.2±4.5 mV, p<0.0t), maximal diastolic potential (80.4±2.2 vs. 58.7±5.4 mV, p<0.05), dV/dt (156.6±12.7 vs. 26.4±6.5 V/sec, p<0.05), and ADPg0 (208.3±7.2 vs. 145.2±7.4 ms, p<0.01), consistent with slow conduction and unidirectional block occurred in the BZ. In conclusion, sustained monomorphic VTs developed after MI were due to functional spiral wave reentry or anatomic macroreentry around the infarction area. Both types of reentries involved in the BZ with delayed conduction and unidirectional block. Background: Increased left atdal volume (LAV) is associated with a higher risk of recurrent atdal fibdllation (AF) and atdal arrhythmias. Two-dimensional (2-D) transthorecic echocardio- graphy is validated as a reliable method by which to assess LAV compared to cine-computed tomography (cine-CT). Using the biplane method of disks, LAV measured by transthoracic echocardiography is well correlated with that obtained by cine-CT, but under estimates the LAV by 20-32%. Magnetic electroanatomic mapping (MEAM) is valuable for defining the ana- tomic location of catheter-based electrophysiologic recordings by creating a detailed shell of the endocardial anatomy in three-dimensional that can help guide focal AF ablation. We sought to validate the accuracy of volume measurements by MEAM by compadng MEAM LAV measurements against those measured by two-dimensionaJ transthoracic echocardiogrephy. Methods: Forty-seven patients underwent 2-D echocardiography and detailed MEAM of the left atdum (LA). The entire LA was mapped with 78-224 distinct points (mean 126 ± 37) acquired dudng atdal end-diastole, MEAM measurement of LAV was computed by using the built-in volume function of the Biosense TM system. The LAV was assessed using 2-D tran- sthoraclc echocardiography by the biplane methods of disks. The endocardial outlined was digitally traced in the apical 4-chamber and 2-chamber views at end-atrial diastole with exclu- sion of the pulmonic veins and appendage. Results: The LAV by 2-D echocardiography was 92.7 + 25.9 cc versus the LAV by MEAM which was 125.4 + 28,4 cc. There is good correlation between the results of echocardio- graphy and MEAM (r=0.90, p<0.001) for LAV, although the average value obtained by echocardiography is about 26% lower than that obtained by MEAM. Conclusions: Magnetic electroanatomic catheter mapping appears to be a retiable method by which to assess LAV. The results of MEAM correlate well with the echocardiographic assessments of LAV. Echocardiography underestimates LAV by a similar percentage when compared to MEAM as it does when compared to cine-CT. MEAM may prove useful in track- ing LAV with repeat mapping procedures and helping to plan post.ablative management. Bmckorounds: There were few reports about the differences between posteroseptal and the other atdoventdcular accessory pathways lAPs) in anatomy and electrophysiology. Methods: The size and shape of coronary sinus (CS) were measured in 21 patients with posteroseptal APs (11 right and 10 Jeff posteroseptal wall), 83 with the other APs (63 left lateral, 13 right lateral, 7 right anteroseptal wall) and 25 control subjects after CS angiogra- phy. CS diameter and morphoiogic features were measured. In 38 patients with APs, we investigated the electrophysiological charactedstics about anterograde and retrograde con- duction over APs, Rssults: The proximal CS in patients with posteroseptal APs was larger than in those with the other APs and the control (13.8 +/- 1.3 mm vs. 10.9 +/- 2.1 mm (p < 0.001) and 9.7 +/- 1.5 mm (p < 0.001), respectively). At a distance of 5 mm from the CS ostium, the CS mea- sured 10.8 +/- 0.8 mm, compared with 8.9 +/- 1.9 mm (p < 0.05) and 8.2 +/- 1.8 mm (p < 0.01). The dilatation persisted 10 mm into the CS, with the measurement of 8.6 +/- 1.2 mm, compared with 7.5 +/- 1.8 mm (p<0.05) and 7.2 +/- 1.7 mm (p<0.05). There were no differ- ences in these distal diameter, tn 67% of patients with posteroseptal APs, the proximal CS had the wind-cone appearance. This morphology was found in 16% of patients with the other APs. In all of control subjects and 84% of patients with the other APs, the CS was the tubular. Only 1 patient with a posteresaptal AP had retrograde and anterograde decremen- tal conduction over the AP. Three patients with postereseptal APs, 2 with left lateral, 2 with dght rataral and 1 with anteroseptal had only retmgrada conduction. Posteroseptal APs with dacramental conduction were located only in the right side. C.onclusions: The larger size of proximal CS was a structural characteristics in patients with posterosaptal APs. The appearance of proximal CS was like a wind-cone in these patients. Right posteroseptal APs were prone to have the high incidences of decremental conduction. These findings may have a clue to trace arrthythmia pathogenesis to its origin.