Evaluation of myocardial damage using 123I-BMIPP imaging in patients with vasospastic angina

The purpose of this study is to determine whether left ventricular dysfunction following coronary artery spasm by 123I-BMIPP myocardial imaging. To reveal the clinical efficacy of 123I-BMIPP SPECT, 20 patients with vasospastic angina were studied using resting, 3-hour delayed image with 123I-BMIPP and exercise, 3-hour delayed image with 201Tl SPECT. 123I-BMIPP uptake was decreased compared to 201Tl (discordant) in 12 patients (60%) and in 49/100 myocardial segments (49%). The extent and severity score in resting image with 123I-BMIPP were significantly larger than that in delayed image with 201Tl (p < 0.01). In 123I-BMIPP SPECT, the severity score in the latest ischemia were significantly larger than that in others. The incidence of a complete agreement of decreased 123I-BMIPP uptake and coronary artery spasm was significantly higher (75%) than that in 201Tl (28%, p < 0.01). Furthermore, compared to 201Tl uptake, decreased 123I-BMIPP uptake much more corresponded to reduced wall motion in 9 of patients with mismatching. The severity of regional wall motion abnormality was significantly correlated with severity score of 123I-BMIPP. Late redistribution in delayed image with 123I-BMIPP was seen in 6 patients. The regional washout rate and the severity of regional wall motion abnormality in 6 patients was significantly lower than that in others (p < 0.05). Thus, metabolic abnormality assessed by 123I-BMIPP is well associated with left ventricular asynergy and spastic region in patients with vasospastic angina. In conclusion, 123I-BMIPP SPECT may sensitively delineate the impaired myocardium following coronary artery spasm, and it is very useful in diagnosing and estimating the severity of vasospastic angina.     

Dental fear with and without blood-injection fear: implications for dental health and clinical practice

BACKGROUND: It has been suggested that the sympathetic nervous system might play an important role in the development of coronary artery spasm. However, no cardiac imaging modality has been able to demonstrate abnormal sympathetic innervation in patients with coronary artery spasm. The purpose of this study was to assess the presence and location of abnormal sympathetic innervation using iodine 123-metaiodobenzylguanidine (123I-MIBG) single photon emission computed tomography (SPECT) and to evaluate the clinical efficacy of 123I-MIBG SPECT as a noninvasive screening test in patients with coronary artery spasm. METHODS AND RESULTS: Coronary arteriography and a provocative test with intravenous administration of ergonovine maleate were performed in 26 patients (20 men, 6 women, mean age 48.2+/-12.0 years, range 20 to 67 years) who were suspected of having a coronary artery spasm. The subjects were divided into 2 groups: group 1 (n = 18) comprised subjects with a positive provocative test result, and group 2 (n = 8) comprised subjects with negative provocative test results. Ten healthy subjects served as controls. No abnormal MIBG uptake was observed in the control subjects. Abnormal sympathetic nervous innervation using 123I-MIBG SPECT was observed either as a reduced uptake or a defective pattern in the perfused areas in 13 of the 18 regions supplied by vessels of ergonovine-induced vasospasm. Normal sympathetic innervation, as evidenced by normal 123I-MIBG uptake, was noted in all of the 60 segments of normal vessel territories. Reduced uptake of 123I-MIBG was not detected in the perfused areas of 5 vasospasm-induced vessels (perfusion territory of left anterior descending coronary artery [LAD] and the right coronary artery [RCA] in 2 and 3 patients, respectively). The sensitivity and specificity of 123I-MIBG for detection of coronary artery spasm were 72.2% (95% confidence interval [CI] 55% to 89%) and 100%, respectively. The positive predictive and negative predictive values were 100% and 92.3% (95% CI 91% to 93%), respectively. CONCLUSION: 123I-MIBG SPECT is a feasible method to evaluate noninvasively and localize the territories of coronary arteries with spasm. Invasive diagnostic coronary arteriography with ergonovine provocation test may be unnecessary for diagnosis of coronary artery spasm in patients with typical resting pain, negative exercise test or normal thallium perfusion scan results, but showing abnormalities in 123I-MIBG SPECT.     

Race and serum prostate-specific antigen levels: current status and future directions

The usefulness of thallium-201 (201Tl) myocardial scintigraphy was studied in 109 patients with vasospastic angina who had nearly normal coronary arteries (degree of stenosis < 50%). Coronary spasm was confirmed by pharmacologic agents in all 109 patients from January 1991 to June 1996. The appearance rate of visual redistribution on 201Tl myocardial scintigraphy was compared between four groups, 34 patients performing graded bicycle ergometer exercise starting at a work load of 50 W with increments of 25 W every 3 min [Ergo (3) group], 14 patients performing hyperventilation for 5 min [HV (5) group], 31 patients performing bicycle ergometer exercise with increments of 25 W every 1 min after 5 min hyperventilation [HV (5) + Ergo (1) group], and 30 patients at rest (Rest group). The value of the visual redistribution rate on 201Tl myocardial scintigrams in the HV(5) + Ergo (1) group (65%) was higher than that in the patients of other groups [Ergo (3) 41%, HV (5) 43%, Rest 33%]. However, there were no significant differences between the four groups. Stress 201Tl imaging after hyperventilation and accelerated exercise is useful to disclose ischemic evidence in about two thirds of patients with vasospastic angina and nearly normal coronary arteries, whereas about 40% of patients had visual redistribution on 201Tl myocardial scintigrams by performing standard procedures.     

A new noninvasive method of diagnosing vasospastic angina based on dilation response of the left main coronary artery to nitroglycerin as measured by echocardiography

OBJECTIVES: The purpose of the present study was to evaluate the feasibility of diagnosing vasospastic angina based on coronary artery tone as assessed by M-mode echocardiographic measurement of the dilation response of the left main coronary artery to nitroglycerin. BACKGROUND: The definite diagnosis of vasospastic angina is done by a coronary spasm provocative test using ergonovine maleate or acetylcholine during cardiac catheterization. Current noninvasive, nonpharmacologic diagnostic methods are not sensitive enough for the diagnosis of vasospastic angina. METHODS: Thirty-eight patients who had an angiographically normal left main trunk were studied. These patients were classified into four groups based on the presence or absence of more than 50% stenosis in the coronary arteries except for the left main trunk and the results of the acetylcholine or ergonovine provocative test. At 7 a.m. and at noon on the same day, the left main trunk diameter was measured by M-mode echocardiography before and after sublingual administration of nitroglycerin (0.3 mg), and its present dilation was calculated to assess coronary artery tone. RESULTS: The percent dilation of the left main trunk diameter induced by sublingual nitroglycerin at 7 a.m. and at noon was 22.4 +/- 4.7% (mean +/- SD) and 18.1 +/- 4.0% in 11 patients with vasospastic angina and without coronary stenosis, 14.9 +/- 7.1% and 11.2 +/- 6.9% in 9 patients with vasospastic angina and coronary stenosis, 6.1 +/- 3.5% and 7.0 +/- 5.1% in 8 patients without vasospastic angina but with coronary stenosis and 8.1 +/- 5.6% and 7.8 +/- 5.7% in 10 control subjects. The percent dilation at 7 a.m. was significantly greater in the vasospastic angina without coronary stenosis group than in the remaining three groups, and in the vasospastic angina groups, the percent dilation at 7 a.m. was significantly greater than that at noon. When percent dilation at 7 a.m. exceeding 15% was defined as positive for the diagnosis of vasospastic angina, the sensitivity was 80% and the specificity 94%. CONCLUSIONS: Basal tone of the left main trunk is elevated in the early morning in vasospastic angina. Dilation of the left main trunk diameter exceeding 15% induced by sublingual nitroglycerin in the early morning as measured by M-mode echocardiography is a highly sensitive and specific criterion for the diagnosis of vasospastic angina.     

Results of a technique of pancreaticojejunostomy that optimizes blood supply to the pancreas

To evaluate whether the flow-mediated vasodilation and coronary flow reserve are impaired or not in patients with vasospastic angina (VA), we measured the changes of epicardial coronary artery diameter and flow reserve in spasm related-left anterior descending coronary artery (LAD). The flow mediated-response of epicardial coronary arteries in 15 VA were compared with 15 controls. Using quantitative coronary angiography, we measured the diameter of proximal (pLAD) and middle segment (mid-LAD) of LAD under baseline conditions, during increased blood flow after distal adenosine injection and after proximal administration of nitroglycerin. An increased fraction of average peak velocity after injection of adenosine was similar in both groups [control 340 (mean)+/-24 (SEM)%; VA 330+/-19%]. Flow-mediated vasodilation was preserved in all controls (pLAD 13.1+/-1.4%; mid-LAD 15.8+/-2.5%) but it was significantly impaired in patients with VA (pLAD -1.0+/-1.8%; mid-LAD 0.1+/-3.5%). The vasodilator response to nitroglycerin was comparable in controls (pLAD 25.8+/-2.8%; mid-LAD 27.2+/-2.8%) and VA (pLAD 26.2+/-5.2%; mid-LAD 26.7+/-3.5%). Coronary flow reserve is preserved in patients with VA. However, the flow-mediated response of spasm related-epicardial coronary artery is impaired. This may play an important role in the pathogenesis of coronary artery spasm.     

Antibodies to prothrombin in antiphospholipid syndrome and inflammatory disorders

The ability to noninvasively assess the patency of coronary stents would represent a significant advance. We evaluated the safety and ability of two-dimensional coronary MR angiography in imaging stents and suggesting patency. Coronary MR angiography of 26 coronary stents (Palmaz-Schatz) was performed in 16 patients 39 to 73 years of age. Studies were performed between 2 and 4 months after stent placement. All patients were symptom free at the time of imaging. Coronary MR angiography was performed with a commercial 1.5-T MR imager using an electrocardiographically gated pulse sequence with breath-holding. Images were obtained in mid-diastole with and without fat suppression. Image artifacts caused by the metal in the stents were clearly visualized in all 26 stents (100% sensitivity for stent detection). Arterial flow signal was seen in the coronary artery or graft distal to the stent in 25 of 26 cases (96%). All patients, except for the one in which distal flow could not be seen, remained symptom free for >2 years. The distribution of stent locations was as follows: 10 in the right coronary artery (RCA), 10 in the left anterior descending coronary artery (LAD), 2 in the left circumflex coronary artery, and 4 in saphenous vein grafts (SVGs) to RCA. One patient had 2 RCA and 2 LAD stents, one had 3 RCA and 1 LAD stents, one had 3 SVG stents, and two had double RCA stents. Coronary MR angiography is safe for noninvasive imaging of coronary stents, and in the proper clinical setting, it can be used to help suggest patency.     

A case of coronary artery bypass grafting for single coronary artery complicated by angina pectoris

A case of coronary artery bypass grafting (CABG) for single coronary artery complicated by angina pectoris (AP) was reported. The patient was a 74-year-old male, complained of anginal discomforts. His single coronary artery originated in left coronary sinus, bifurcated to the left anterior descending artery (LAD) and the circumflex artery (CX), and then, an abnormal communicating branch, passing in front of the right ventricular outflow, was branched from the proximal region of LAD; it showed a route corresponding to the proximal region of the right coronary artery (RCA). The distal region of RCA and the posterior descending artery were angiographed in continuity from CX. Other findings included 75%-stenosis at LAD-#6 and 90%-stenosis at CX-#13. Using two saphenous vein grafts, CABG operation was carried out on those regions at LAD-#7 and distal CX corresponding to #3 normally. Postoperatively, anginal discomforts disappeared, and favorable results were obtained.     

Technetium-99m teboroxime regional myocardial washout in subjects with and without coronary artery disease

The aim of this study was to test the hypothesis that regional myocardial washout of technetium-99m teboroxime is slowed in the presence of coronary stenosis. Washout was assessed in 33 catheterized patients and in 13 with a low likelihood of coronary artery disease, using a triple detector camera and dynamic single-photon emission computed tomography, with serial 1-minute acquisitions after injection of 20 to 25 mCi of teboroxime at the third minute of adenosine-induced hyperemia. Washout was measured as the percent change in counts between the first, second and third minutes after injection, as measured in 6 short-axis myocardial regions of interest. Myocardial regions were classified as ischemic (> or = 50% diameter stenosis and no prior myocardial infarct), infarcted, normal (no significant coronary stenosis) or "low likelihood" (from the 13 patients with a low likelihood of coronary artery disease). Teboroxime washout was significantly (p < 0.001) slowed in the ischemic myocardium (12.7 +/- 8.3%) compared with the normal (18.5 +/- 5.7%), low-likelihood (17.8 +/- 6.1%) and infarcted (17.8 +/- 4.4%) zones. There was regional variability in washout rates (% washout/min), with the anterior wall having the lowest (13.8 +/- 3.4%/min) and the inferior wall the highest (20.7 +/- 7.9%/min) values. In regard to individual coronary territories, 21 of 41 ischemic, noninfarcted territories (51%) had abnormal washout compared with 3 of 43 normal territories (7%) (p = 0.001). In conclusion, regional washout of teboroxime is detectably slowed in ischemic, noninfarcted myocardium. The clinical value of washout analysis in teboroxime single-photon emission computed tomography warrants further investigation.     

Increased serotonin release across the coronary bed during a nonischemic interval in patients with vasospastic angina

BACKGROUND: Platelet activation and coagulation abnormality have been observed during coronary spasm. It is crucial whether platelet activation occurs even during a nonischemic period. HYPOTHESIS: This study was designed to determine whether platelets might be activated across the coronary bed during a nonischemic interval in patients with vasospastic angina. METHODS: Plasma levels of serotonin, 6-keto-prostaglandin F1 alpha, and catecholamines in the aorta and the coronary sinus were simultaneously measured in 16 patients with vasospastic angina and 13 control patients with nonischemic heart disease. RESULTS: None of these patients showed myocardial ischemia during sampling. The difference in transcardiac plasma levels of serotonin in patients with vasospastic angina was significantly higher than that in controls (1.48 +/- 1.08 ng/ml vs. 0.07 +/- 0.12 ng/ml, respectively, p < 0.001). Coronary sinus plasma norepinephrine levels in these two groups were almost the same (204.8 +/- 110.8 pg/ml vs. 190.4 +/- 131.6 pg/ml, respectively). The ratio of 6-keto-prostaglandin F1 alpha in the coronary sinus and the aorta was not different between the two groups (1.17 +/- 0.96 in patients with vasospastic angina vs. 1.15 +/- 0.68 in controls). CONCLUSIONS: These data suggest that platelet activation across the coronary bed should be ascribed to endothelial dysfunction. Lack of compensatory enhancement of prostacyclin production might be concerned with dysfunction of coronary endothelial cells in these patients.     

The results of questionnaire on quantitative assessment of 123I-metaiodobenzylguanidine myocardial scintigraphy in heart failure

This study was done by working group under the cooperation between Japanese Society of Nuclear Medicine and Japanese Circulation Society. We evaluated the usefulness of quantitative assessment of 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy in heart failure by the results of questionnaire. Forty-nine (72.1%) of 68 selected institutions participated in this study. The incidence of MIBG myocardial scintigraphy used in heart failure was 41.1%. The imaging protocol was mostly done by both planar and SPECT at 15 min and 3.6 hr after intravenous injection of 111 MBq of MIBG. The quantitative assessment was mostly done by heart/mediastinum (H/M) ratio and washout rate analysis based on planar imaging. The mean normal value of H/M ratio were 2.34 +/- 0.36, and 2.49 +/- 0.40, at early and delayed images, respectively. The normal value of washout rate was 27.74 +/- 5.34%. On the other hand, those of H/M ratio in heart failure were 1.87 +/- 0.27, and 1.75 +/- 0.24, at early and delayed images, respectively. That of washout rate was 42.30 +/- 6.75%. These parameters were very useful for the evaluation of heart failure. In conclusion, MIBG myocardial scintigraphy was widely used for not only early detection and severity assessment, but also indication for therapy and prognosis evaluation in heart failure patients.     

Hyperventilation test: a noninvasive screening test for coronary vasospasm

3 patients with coronary vasospasms in different clinical situations are presented. One patient had typical Prinzmetal angina but coronary arteries without significant stenosis. One patient without typical angina pectoris showed sudden significant ST elevations on anterior and lateral ECG tracings accompanied by typical ischemic chest pain. At angiography, a 70% LAD stenosis was found without high degree lesions. One patient (aged 30 years) had a documented anterior infarction with angiographically normal coronary arteries. In all these cases coronary vasospasms were recognized as the underlying cause of the symptoms. All the patients were treated with calcium channel blockers and have been asymptomatic since. Currently available data comparing the diagnostic value of hyperventilation with other tests for coronary vasospasms, such as ergonovine or acetylcholine, are discussed. The hyperventilation test can be recommended as the first test in the work up of suspected vasospastic angina pectoris.     

Computer-assisted imaging of embryonic and fetal development. Background, recommendations and overview

A 65 year-old white man, with typical angina pectoris, underwent coronary angiography that showed dual left anterior descending artery (LAD), originating from the right coronary artery (RCA), associated with anomalous origin of the left circumflex artery (LCX) also from the RCA. This an extremely rare coronary artery anomaly and, it is the first case reported, so far. This rareness and clinical significance are emphasized.     

Pharyngeal lipoma with cartilaginous metaplasia (chondrolipoma): a case report and literature review

We report two cases of vasospastic angina associated with anaphylactic reaction caused by nonsteroidal anti-inflammatory drugs (NSAIDs). Both patients exhibited anaphylactic manifestations, such as general rash and urticaria, along with angina pectoris with electrocardiographic ST-segment elevations after suppository administration of diclofenac sodium or indomethacin, the most commonly used NSAIDs. Although these patients had normal coronary arteriograms, intracoronary administration of ergonovine or acetylcholine provoked diffuse coronary artery spasms accompanied by chest pain and ischemic ST-segment changes. It is therefore suggested that an allergic mechanism may be involved as a causative factor of the coronary artery spasm induced by NSAIDs.     

Insulin resistance associated with compensatory hyperinsulinemia as an independent risk factor for vasospastic angina

BACKGROUND: It is generally believed that coronary artery spasm plays an important role in the progression of obstructive coronary artery disease. Since insulin resistance together with hyperinsulinemia plays an important role in the pathogenesis of coronary atherosclerosis, we investigated the association of hyperinsulinemia and insulin resistance with vasospastic angina (VAP). METHODS AND RESULTS: The study population consisted of 60 patients with VAP and 42 control subjects (62 subjects with normal glucose tolerance and 40 with impaired glucose tolerance). Insulin sensitivity was determined by the steady-state plasma glucose (SSPG) method for nondiabetic, normotensive, nonobese subjects (16 control subjects, 16 obstructive coronary artery disease patients, and 16 VAP patients). Compared with the control group, the 2-hour insulin area (area under the plasma insulin concentration-time curve) during a 75-g oral glucose tolerance test was significantly higher in both VAP groups with normal and impaired glucose tolerance. A high frequency of vasospastic angina was observed in subjects with clustered risk factors for insulin resistance syndrome, suggesting a close association of VAP with this syndrome. In stepwise discriminant analysis, the 2-hour insulin area was significantly associated with VAP independent of other risk factors. SSPG level in VAP was about twofold over control, indicating the presence of insulin resistance in patients with VAP. However, no differences were found between patients with VAP and obstructive coronary artery disease with respect to mean SSPG level. CONCLUSIONS: SSPG level was significantly elevated in patients with VAP and obstructive coronary artery disease compared with control subjects. This indicates that hyperinsulinemia is secondary to insulin resistance, both of which are thought to play important roles as risk factors for VAP in the early atheromatous lesion and in the future development of occlusive lesions when chronically present.     

Coronary endarterectomy revisited: mid-term angiographic results

OBJECTIVES: To evaluate the value of concomitant coronary endarterectomy (CE) in the modern era of coronary revascularization. METHODS: Retrospective study. Twenty-eight patients (five women; 23 men) who underwent coronary endarterectomy were angiographically studied 24 +/- 22 months after the procedure. Necessity CE (vessel completely occluded or with lumen less than 1 mm) was performed on the left anterior descending (LAD) artery in 12 patients, the right coronary artery (RCA) in nine, the obtuse marginal artery (OM) in five and a diagonal branch in two patients. Conduits used for revascularization were the internal thoracic artery (ITA) in 11 (all anastomosed to the LAD; combined with saphenous vein patch in four) and a saphenous vein graft in 17 patients. Mean atherosclerotic core length was 3.3 +/- 1.8 cm. An average of 3.1 +/- 0.7 distal anastomoses per patient were constructed, with mean aortic cross-clamp and cardiopulmonary bypass times of 61.2 +/- 20.2 mins and 94.0 +/- 23.5 mins, respectively. RESULTS: Overall, angiographic patency rate was 71% (20 of 28) for the endarterectomized vessels (12 of 12 LAD, six of nine RCA, two of five OM and none of two diagonal arteries) and 93% (57 of 61) for the nonendarterectomized vessels. Among the eight patients with occluded CE vessels, two sustained a perioperative myocardial infarction, five developed angina during follow-up, and one patient remained asymptomatic. CONCLUSION: Necessity CE demonstrates acceptable mid-term patency. In addition, this study showed excellent patency following CE of the LAD revascularized with the ITA, with or without only a saphenous vein patch.     

Studies on immobilization of aminoacylase on the functionalized polymethyl acrylate

The effect of nicorandil on myocardial perfusion in ischaemic heart disease has been studied using exercise-load T1-201 myocardial SPECT (Ex-SPECT). Ex-SPECT was carried out in 12 patients with previous myocardial infarction (OMI) and 9 with angina pectoris (AP) before and after administration of nicorandil 15 mg/day, for three or more weeks; % T1 uptake and the washout rate in infarcted or ischaemic areas were calculated from short axial images using the Bull's eye method. In the OMI group, % T1 uptake and washout rates in the infarction areas improved significantly from 52.4% and 0.25 before nicorandil to 60.4% and 0.38 after it. In the AP group, too, % T1 uptake and washout rates showed a significant improvement from 56.9% and 0.10 before to 69.1% and 0.33 after administration. Six subjects who had not received the drug, and who showed negative washout rates, had high improvement rates when nicorandil was administered, suggesting that the drug could increase myocardial perfusion during exercise loading as well as suppressing coronary spasm. Ex-SPECT was done in 4 subjects before and after nicorandil and after subsequent surgical treatment (PTCA or CABG) and the effects of the two therapies were compared. The washout rate was improved from 0.01 to 0.34 by administration of nicorandil, and a notable increase in coronary artery blood flow was achieved compared to the level after surgical treatment, i.e. 0.50. It was concluded that, normal dosages of nicorandil have a powerful direct effect of dilating the coronary arteries without any influence on preload or afterload.     

Atopic dermatitis and related factors observed at infant physical examination at health centers

OBJECTIVE: To evaluate the clinical usefulness of cardiac SPECT in the detection of coronary artery disease, and the relation with the site, number and severity of the angiographic lesions. METHOD: We studied 216 patients; with myocardial perfusion imaging with SPECT (T1-201 and/or Tc-99 Sestamibi) and coronary angiogram. We defined the localization of myocardial perfusion defects (anterior, inferior, septal, lateral or apex), and their correlation with coronary angiogram, based on the location, number and severity of coronary angiographic lesions. We considered significative coronary stenosis obstructions of 60% or more. RESULTS: Of the 216 patients studied, 181 (83.8%) were male and 35 (16.2%) female. Age ranged between 30 and 82 years; 143 males and 23 females had a previous myocardial infarction. The SPECT sensitivity for diagnosing ischemia of one, two and three vessel disease was 94%, 96% and 100%. The sensitivity for diagnosing disease in specific vascular territories was 91.6% for LAD 100% for RCA, 92.8% for CX and 100% for left main. CONCLUSIONS: Myocardial perfusion imaging with SPECT has high sensitivity for diagnosing coronary artery disease. The sensitivity and specificity were more accurate in proximal anterior descending artery disease, left main and three-vessel coronary artery disease. We found correlation in the site, number and severity of the angiographic lesions and in myocardial perfusion defects.     

99mTc-HL91: "hot spot" detection of ischemic myocardium in vivo by gamma camera imaging

BACKGROUND: 99mTc-HL91 is a new hypoxia imaging agent that demonstrates increased uptake and retention in globally hypoxic myocardium in vitro. The purpose of this study was to determine whether 99mTc-HL91 could detect regional ischemia in vivo by gamma camera imaging. METHODS AND RESULTS: Eight open-chest dogs with left circumflex (LCx) stenoses were studied. Injection of 5 mCi of 99mTc-HL91 and microspheres was followed by imaging over 4 hours. Heart slices were imaged, then stained with triphenyltetrazolium chloride (TTC), and tissues were well-counted. TTC staining demonstrated no injury. Mean LCx blood flow was 0.32+/-0.04 mL x min(-1) x g(-1), and mean left anterior descending coronary artery (LAD) flow was 0.96+/-0.02 mL x min(-1) x g(-1) (ratio, 0.33). "Hot spots" were detected in 8 of 8 experiments in vivo within 60 minutes and improved over 4 hours. Region of interest analysis of LCx/LAD activity ratios demonstrated significant increases within 30 minutes (final ratio, 3.0; P<0.05). LCx and LAD washout curves demonstrated significant differences within 15 minutes. Washout curves were biexponential over 1 hour, followed by linear retention from 1 to 4 hours. Four-hour fractional retention was 0.12 for LAD and 0.44 for LCx (P<0.01). Myocardial flow versus tracer uptake demonstrated 2 phases: phase 1 (flow, 0.05 to 0.7 mL x min(-1) x g(-1)) had an inverse linear correlation (r= -0.80); phase 2, (flow, >0.7 mL x min(-1) x g(-1)) had no correlation. Ischemic heart/liver ratios remained near 1.0 for 4 hours. CONCLUSIONS: 99mTc-HL91 positively identifies regional myocardial ischemia in a canine model using 99mTc imaging. Quantitative techniques allowed identification of ischemic myocardium within 15 minutes of tracer administration.     

An evaluation of the British Army spatial disorientation sortie in U.S. Army aviation

A 68-year-old female whose myocardial sympathetic function was severely damaged with multi-vessel vasospastic angina is presented. She had no signs of autonomic dysfunction or diabetes mellitus. Myocardial imaging with 123I-MIBG showed extremely diminished uptake, but 201TlCl and 123I-BMIPP SPECT images were almost normal. Coronary arteriography revealed no significant atherosclerotic stenosis, multivessel spasm was observed by provocation test using acetylcholine. The extremely diminished uptake of 123I-MIBG was slightly increased in response to medication and the subsequent improvement of the patient's condition. Markedly decreased uptake with 123I-MIBG myocardial scintigraphy was considered to be due to multi-vessel spastic angina. We believe that this method of imaging study is useful for evaluating the healing stage of myocardial sympathetic dysfunction.     

Extraocular muscle surgery in myotonic dystrophy

A 44-year-old woman with severe variant angina refractory to maximal medical therapy and at risk of sudden death was successfully treated by a NIR stent implantation on a moderate lesion of LAD. Six months later she was asymptomatic, without in-stent restenosis. This procedure represents an alternative treatment for patients with refractory vasospastic angina.