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Objectives: This study investigated the tissue characterization of human coronary artery plaque using Virtual Histology intravascular ultrasound (VH-IVUS) and temperature guide wire., Methods and Results: Between August 2005 and December 2005, VH-IVUS examination and guide wire based measurement of coronary temperature were performed in 66 patients: 39 with stable angina pectoris (SAP), and 27 with unstable angina pectoris(UAP). Patients in the acute myocardial infarction with necrotic tissue and thrombus were excluded. After measurement of distal coronary pressure and coronary temperature, the following tissue types of atherosclerotic plaque were evaluated by VH-IVUS: fibrotic, fibro-fatty, dense calcium and necrotic core. Occurrence of fibro-fatty tissue was significantly higher in UAP patients than in SAP patients (17.4 +/- 7.0% vs 11.2 +/- 5.2%, p = 0.04), and coronary temperature was significantly higher in UAP patients than in SAP patients (0.08 +/- 0.05 vs 0.03 +/- 0.02 degrees C, p = 0.01)., Conclusions: These results suggest that the combination of VH-IVUS analysis and measurement of coronary temperature may be able to predict the progression of lesions.

An 86-year-old man with chest pain was admitted to our hospital. Coronary angiography revealed 99% stenosis of the mid segment of the left anterior descending coronary artery, therefore, a coronary stent was implanted. Immediately after the stent implantation, 99% stenosis occurred at the proximal site of the 1st diagonal artery because of stent jeal. On the 4th hospital day, ECG-gated 201TL/99mTc-PYP dual myocardial quantitative gated SPECT was performed at rest and during low-dose dobutamine loading. The 201Tl scintigraphy revealed moderately reduced uptake in the anterior, septal and apical walls, and 99mTc-PYP uptake was observed in the mid-anterior wall. A three-dimensional surface display of gated 201Tl SPECT images showed severe hypokinesis in the anterior, septal and apical walls at rest. On the other hand, during low-dose dobutamine loading, improved wall motion was observed in the basal anterior and septal walls, while no change was observed in the midanterior and apical wall movements. Three-dimensional surface display of gated 201Tl/99mTc-PYP dual SPECT images revealed similar patterns of wall motion as those of gated 201Tl SPECT images at rest. During low-dose dobutamine loading, on the other hand, a three-dimensional surface display of gated 201Tl/99mTc-PYP dual SPECT images revealed improved wall motion in the basal anterior, septal and apical walls, but worsened wall motion of the mid-anterior wall. After 6 months, a follow-up coronary angiography revealed no re-stenosis of the stent, but 99% stenosis at the proximal aspect of the 1st diagonal artery. Left ventriculography revealed improved wall motion in the apex and akinesis of the mid-anterior wall. These wall motion findings were similar to those visualized in the three-dimensional surface display of gated 201Tl/99mTc-PYP dual SPECT images during low-dose dobutamine loading in the acute phase. These results suggest that 201Tl/99mTc-PYP dual myocardial quantitative gated SPECT using low-dose dobutamine loading could be useful for the assessment of myocardial viability after reperfusion therapy in patients with acute myocardial infarction.

A 97-year-old woman was provoked a convulsion after taking a new quinolone antibiotic drug Levofloxacin and a non-steroidal anti-inflammatory drug Loxoprofen. At a later time, she was suffered from severe chest pain. An electrocardiogram showed ST segment elevation in leads II, III and aVF, and T-wave inversion in leads V1 to V4. Coronary angiography demonstrated no organic stenosis, however biventriculography revealed apical ballooning akinesis and basal hyperkinesis. Positron emission tomography was also performed to assess the uptake of 18F-fluorodeoxyglucose (FDG) after 75 g oral glucose loading for evaluating myocardial glucose metabolism at 10th day. Severely reduced uptake of FDG was observed in the apical ballooning region. Left ventriculography showed normal wall motion at 19th day. Thallium-201 myocardial single-photon emission computed tomography (SPECT) to determine the status of myocardial perfusion at the 20th hospital day showed normal perfusion. Iodine-123-beta-methyl-p-iodophenyl penta-decanoic acid myocardial SPECT to evaluate myocardial fatty acid metabolism at the 23rd day revealed severely reduced uptake in the apical ballooning region. These findings suggested that the coronary microcirculation was impaired in the apical ballooning region.

This patient was a 64-year-old man with chest pain at rest. An electrocardiogram showed depression of the ST segment in V2-V5 leads during chest pain. 123I-BMIPP myocardial SPECT revealed reduced uptake in the apex. Coronary angiographies revealed severely delayed filling of contrast medium without narrowing of epicardial coronary arteries. An intracoronary infusion of isosorbide dinitrate did not improve the delayed filling of contrast medium or the ST segment depression. After an intracoronary infusion of nicorandil, coronary arterial flows were remarkably improved, chest symptoms disappeared, and electrocardiographic findings were improved. Left ventriculography showed severe hypokinesis in the apex. After the medication with nicorandil, reduced 123I-BMIPP myocardial uptake and reduced wall motion on echocardiography were improved. These findings suggest that myocardial ischemia in this case might be explained as having been caused by microcirculation disturbance.

Unlabelled: Patients with coronary ectasia often develop chest pain and reveal ischemic changes on electrocardiograms and reduced left ventricular wall motion on left ventriculography, in the absence of epicardial coronary artery stenotic regions. We examined the disturbances in the coronary microcirculation in patients with coronary ectasia using left ventriculography and ATP loading 99mTc-tetrofosmin myocardial single photon emission computed tomography (SPECT) before and after administration of a coronary vasodilator and antiplatelet agents., Methods: Twenty patients in whom coronary angiography revealed diffuse coronary artery ectasia but no stenotic regions were enrolled in this study. Left ventriculography and ATP loading 99mTc-tetrofosmin myocardial SPECT were performed before and after administration of the coronary vasodilator, nicorandil, as well as that of the antiplatelet agents, aspirin and ticlopidine., Results: (1) The ejection fraction in left ventriculography was 48.3 +/- 17.4% before, and 56.6 +/- 18.3% after the drug administration, the ejection fraction was improved after the drug administration (p < 0.05). (2) Before the drug administration, the total defect scores on 99mTc-tetrofosmin myocardial SPECT were 5.9 +/- 3.1 and 8.8 +/- 2.7 in the ATP-loading and rest images, respectively (p < 0.05), and the corresponding scores after the drug administration were 4.1 +/- 3.0 and 5.4 +/- 3.1, respectively (N.S.). Thus, the total defect scores in the ATP-loading and rest images improved after the drug administration (p < 0.05)., Conclusion: Myocardial damage in patients with coronary ectasia might be induced by microthrombotic embolism and microcirculation disturbance.