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BACKGROUND Thallium-201 has been widely used in clinical practice for the management of coronary heart disease, but little is known regarding its kinetics in the acute phase of myocardial infarction. CASE REPORT We report a 78-year-old man who developed acute inferior myocardial infarction during exercise thallium-201 scintigraphy. The patient underwent exercise testing with thallium-201 myocardial scintigraphy because of a single episode of chest pain. The workload was started with 25 watts and increased by 25 watts every 2 min on a bicycle ergometer with continuous monitoring of 12-lead electrocardiography. Thallium-201 was injected intravenously at 85% of the age-predicted maximal heart rate, and ST-segment elevations refractory to medication subsequently developed in the inferior leads, followed by chest pain. Scintigraphic image acquisition was deferred and he was transferred to the catheter laboratory in this hospital. Emergency coronary angiography showed occlusion in the right coronary artery, and stent implantation was successfully performed. The peak level of creatine kinase in the clinical course was 201 U/l. Scintigraphic images obtained 4 h after the onset of ST-segment elevation showed severely reduced activity in the left ventricular inferior wall, with partial redistribution 24 h later. Follow-up imaging performed 4 months later revealed increased accumulation of thallium-201 in the inferior wall. CONCLUSIONS Our case highlights the kinetics of thallium-201 during acute myocardial infarction.

Background: Acute inferior myocardial infarction (MI) often induces transient sinus bradycardia through vagal enhancement, known as Bezold-Jarisch reflex, which is explained by preferential distribution of vagal nerve in the inferior wall. We examined vagal activity in relation to the occurrence of residual ischemia in patients with old inferior MI and assessed its diagnostic usefulness., Methods: Exercise myocardial scintigraphy was performed in 15 patients with old inferior MI, 19 angina pectoris (AP) patients with inferior ischemia but no MI, and 32 control subjects who had no evidence of cardiac disease. We analyzed the connection of residual ischemia in old MI with ST-segment response to exercise and with vagal activity as determined by coefficient of component variance of high frequency (CCV(HF))., Results: Exercise-induced percentage change in CCV(HF) was higher in patients with old MI and residual ischemia (18.8 +/- 13.5%) and AP (5.5 +/- 9.7%) than old MI but no residual ischemia (-24.1 +/- 4.9%) or control (-22.8 +/- 4.5%, P = 0.006). Percentage change in CCV(HF) > -5% had a good diagnostic value for the detection of residual ischemia in patients with old inferior MI with sensitivity of 83%, specificity of 89%, accuracy of 87%, and positive likelihood ratio of 7.50, which was higher than that of ST-segment depression (67%, 50%, 56%, and 1.33)., Conclusions: Vagal enhancement was associated with residual ischemia in old inferior MI as well as inferior AP. Measurement of CCV(HF) is useful in improving the diagnostic reliability of exercise electrocardiography in patients with old inferior MI.

Short-term fluctuations in sinus cycle length after a single ventricular premature complex (VPC) have attracted considerable interest and has been termed heart rate turbulence (HRT). The onset and slope of HRT have each been reported to be independent and powerful predictors of clinical prognosis in patients with myocardial infarction (MI), but there are no data available for patients with hypertrophic cardiomyopathy (HCM). Thus the present study analyzed the 2 HRT variables to determine their prognostic value in HCM patients. Holter monitoring data were obtained from 104 HCM patients, 44 MI patients and 56 normal controls, from which singular VPCs followed by >or=20 normal sinus beats were isolated and the HRT onset and slope were automatically calculated. HRT onset and slope were abnormal in MI patients, but not in HCM patients, as compared with normal control subjects (onset -1.1+/-2.9, -2.1+/-3.4, -1.4+/-5.1%; slope 10.6 +/-8.6, 18.0+/-13.9, 16.6+/-9.7 ms/beat, respectively). During the follow-up period of 27+/-10 months, 7 HCM patients and 10 MI patients either died from cardiac death or were hospitalized for congestive heart failure. In MI patients, HRT onset was higher and the HRT slope was lower in patients with cardiac events than in patients without (onset 1.1+/-2.7 vs -1.7+/-2.7%, p=0.011; slope 5.7+/-4.3 vs 12.0+/-9.0 ms/beat, p=0.028). In HCM patients, however, the HRT onset and slope were similar between patients with and without cardiac events (onset -2.0+/-2.0 vs -2.1 +/-3.5%, p=0.98; slope 18.1+/-10.9 vs 18.0+/-14.0 ms/beat, p=0.68). In conclusion, unlike MI patients, the HRT variables in selected HCM patients were not abnormal and failed to predict the clinical prognosis.

Abstract: A case of ST-segment elevation provoked by distended stomach conduit is presented. An 83-year-old woman was admitted to our hospital with worsening chest discomfort. She had a previous history of subtotal esophagectomy, which was reconstructed using a stomach conduit in the posterior mediastinum. Electrocardiogram showed ST-segment elevation in the inferior leads and a prominent negative P wave in lead V1. Echocardiography demonstrated normal left ventricular function without regional wall motion abnormality; however, the left atrium and ventricle compressed by a substantially distended stomach conduit was noted. Subsequent angiocardiography revealed no coronary atherosclerotic stenosis and normal contractility of the left ventricle. Chest symptoms resolved soon after nasogastric suction, leading to resolution of electrocardiographic changes. The stomach conduit diminished on following repeated echocardiography. The patient was discharged without any evidence of myocardial infarction. Esophagus disease of the reconstructed stomach conduit should be recognized as a rare but considerable cause for electrocardiographic changes. [Copyright &y& Elsevier]