[Problem of false positives in dipyridamole-echocardiography test. Description of a case and review of the literature].
Dipyridamole-echocardiography may be considered, at this time, an useful test not only in post-infarction risk stratification, but also in diagnosis and functional evaluation of coronary artery disease, having a satisfying sensibility (67%) and a very high specificity (96%). We report a particular case of "false positive" with a review of the literature. The patient, male, aged 45, without important risk factors for coronary artery disease, experimented recurrent events of spontaneous chest pain, typical per angina pectoris. Physical examination, chest roentgenogram and blood samples were normal. Slight signs of subendocardial ischemia, lateral, were present at ECG. Forced hyperpnea resulted in onset of chest pain, with increase of ECgraphic signs of ischemia; resolution of both was obtained with sublingual nitrate administration. A stress test with myocardial flow scintigraphic assessment using sestaMIBI, was performed: ECG showed significant ST downsloping at low workload (1-11 steps of Bruce protocol) and radionuclide tomography showed reversible hypoperfusion in anterior and septal regions. High dose dipyridamole-echocardiography test (a first bolus of 0.56 mg/kg in 4', followed after 4' by a second bolus of 0.28 mg/kg) gave these results: basal echocardiogram was normal; after first bolus of dipyridamole apical hypokinesia appeared; after second bolus complete akinesia was observed. ECG showed subendocardial injury wave and the patient experimented typical anginal pain. Clinical, electrocardiographic and echocardiographic changes were immediately reversed after intravenous bolus of aminophylline, 240 mgs. Coronary arteriography was performed: coronary arteries were angiographically normal, without even any marginal irregularity: left ventricle was normal in volume, wall kinesis and ejection fraction. Dipyridamole is a powerful ischemic stressor.(ABSTRACT TRUNCATED AT 250 WORDS)
Piccone
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Divisione di Cardiologia, Ospedale San Carlo Borromeo, Milano.
Caprari
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M
D017023:Coronary Angiography; D003327:Coronary Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging; D003329:Coronary Vasospasm / Q000175:diagnosis; D004176:Dipyridamole; D004452:Echocardiography; D004562:Electrocardiography; D005189:False Positive Reactions; D006801:Humans; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi
D004176:Dipyridamole; D017256:Technetium Tc 99m Sestamibi