1/8. Apical aneurysm in a patient with apical hypertrophic cardiomyopathy.Apical hypertrophic cardiomyopathy (AHC) is a variant of hypertrophic cardiomyopathy (HCM) in which the hypertrophy predominantly involves the left ventricular apex. The typical features of AHC include giant negative T waves in the precordial ECG leads, a spade-like configuration of the left ventricle at end-systole, the absence of an outflow tract pressure gradient, and mild symptoms. We present a patient with AHC, evidence of prior myocardial infarction with aneurysm of the apical region, and myocardial ischemia on radionuclide scanning despite angiographically normal coronary arteries. The characteristic electrocardiographic, echocardiographic, hemodynamic and angiographic findings as well as prognosis and treatment options are discussed.- - - - - - - - - - ranking = 1keywords = radionuclide (Clic here for more details about this article) |
2/8. Myocardial salvage following elective angioplasty for total coronary occlusion.A 65-year-old man with unstable angina had a critical left anterior descending coronary artery stenosis which progressed to total occlusion, without evidence of acute myocardial infarction. thallium imaging revealed defects in the distribution of the left anterior descending coronary artery on exercise and redistribution, 4 h later. 99mTc radionuclide angiography showed a fall in left ventricular ejection fraction on exercise, and contrast cineangiography showed an extensive area of akinesia. Percutaneous transluminal coronary angioplasty was successful without any complications. Repeat radionuclide studies demonstrated improvement of both myocardial perfusion and function. Angiography at 1 year showed normal left ventricular contraction and no evidence of recurrent stenosis. The patient is free of angina, on no medication 2 years after angioplasty. This case illustrates the feasibility of myocardial salvage by elective coronary angioplasty in patients with unstable angina total coronary occlusion.- - - - - - - - - - ranking = 2keywords = radionuclide (Clic here for more details about this article) |
3/8. Intracoronary myocardial perfusion imaging: patterns in patients with coronary artery disease.Myocardial imaging following the intracoronary injection of radiolabeled particles is used to identify transmural scars in patients being evaluated for coronary atherosclerosis. Selective imaging of the microcirculation derived from each major coronary vessel is accomplished using a dual radionuclide technique. This report illustrates the various normal and abnormal imaging patterns encountered in patients with coronary artery disease. The regional myocardial nomenclature proposed by the american heart association Council on Cardiovascular Surgery is used. Correlation of the nuclear study with the contrast arteriogram and ventriculogram is essential for identifying both transmural scars and regions of collateral circulation. The procedure is safe and can be performed during routine coronary angiography.- - - - - - - - - - ranking = 1keywords = radionuclide (Clic here for more details about this article) |
4/8. Nondominant right coronary artery disease. A source for right ventricular infarction, anginal pain, and a positive exercise electrocardiogram.A patient is described who presented with isolated episodes of typical angina pectoris. Subsequent exercise electrocardiogram was positive, and cardiac catheterization revealed a 90 percent lesion of a nondominant right coronary artery supplying only the right ventricular (RV) myocardium. The left coronary artery was normal. Stress gated equilibrium radionuclide angiograms (rna) revealed a normal left ventricular exercise response and a markedly abnormal RV response (RV ejection fraction decreased from 31 percent at rest to 27 percent at peak stress). Nondominant right coronary artery lesions can be a source of angina pectoris, RV infarction, and a positive ECG response to exercise. Stress rna can be useful in evaluating the functional significance of these lesions.- - - - - - - - - - ranking = 1keywords = radionuclide (Clic here for more details about this article) |
5/8. Coronary artery steal secondary to coronary arteriovenous fistula.Coronary arteriovenous fistula in adults may be associated with angina pectoris. It has been suggested that the cause of the angina is a coronary artery steal of blood into the fistula but this has not been demonstrated. To study its hemodynamics the authors describe two cases of coronary artery fistula. They discuss the use of radionuclide angiography in this setting. The surgical technique is outlined and the use of intraoperative electrocardiographic monitoring is emphasized.- - - - - - - - - - ranking = 1keywords = radionuclide (Clic here for more details about this article) |
6/8. Cardiac rehabilitation: evidence for improvement in myocardial perfusion and function.Sixteen patients with coronary heart disease (CHD) were studied with rest and exercise thallium scans and gated radionuclide ventriculography before and after 3 to 12 months of exercise training. The 5 patients presented in this report showed improvement in both the ejection fraction and exercise thallium images after training while achieving a higher maximal workload and an equivalent double product. These radionuclide techniques have provided the 1st documentation of improvement in both myocardial perfusion and function in CHD patients after exercise training. A controlled study using advances in imaging technology with patients matched according to postmyocardial infarction time and by the severity of disease is underway to confirm these findings.- - - - - - - - - - ranking = 2keywords = radionuclide (Clic here for more details about this article) |
7/8. Dual isotope stress testing in congenital atresia of left coronary ostium. Applications before and after surgical treatment.A 38-year-old women presented with an 11-year history of angina pectoris. Coronary arteriography disclosed a large right coronary artery which filled the entire left coronary tree retrogradely. The left main coronary artery ended blindly and was not connected to the aortic root. There were no atherosclerotic lesions in any vessel. exercise thallium-20l scintigrams showed a perfusion defect in the anterior region of the left ventricle and exercise first pass radionuclide ventriculography showed anterior hypokinesis of the left ventricle with an ejection fraction of 54 per cent, compared with 60 per cent at rest. An aortocoronary saphenous vein graft was constructed to the left coronary artery. Four months after operation the patient is free from symptoms. Repeat thallium scintigrams were normal. exercise radionuclide ventriculography after operation disclosed no wall motion abnormality, and ejection fraction on exercise was 70 per cent. The mechanism of angina in this patient is unclear but may have been related to the abnormal timing of delivery of blood to the left ventricular myocardium. Dual radionuclide stress testing showed abnormalities after operation. This non-invasive approach may be useful in the assessment of the physiological significance of coronary anomalies and of the value of corrective surgery.- - - - - - - - - - ranking = 3keywords = radionuclide (Clic here for more details about this article) |
8/8. Prinzmetal's angina with coronary artery spasm. Angiographic, pharmacologic, metabolic and radionuclide perfusion studies.We studied the effects of coronary artery spasm on perfusion of the microvasculature in a patient with Prinzmetal's angina. Intracoronary injections of 99mTc and 131I-labelled macroaggregated human serum albumin were performed (1) at rest, (2) during spontaneous angina, (3) after the administration of nitroglycerin and (4) during pacing-induced spasm and the resultant scans compared. The resting scan was normal. pain and spasm were associated with a perfusion defect that was localized to the anterior and inferior walls of the left ventricle. The localization of the perfusion defect corresponded with angiographically demonstrated spasm involving left anterior descending and distal circumflex coronary arteries. A subsequent myocardial infarction was localized by 43K scanning to the same perfusion area. Metabolic and parasympathetic stimulation studies were performed but were inconclusive. The patient's recurrent pains were ultimately controlled with large oral doses of isosorbide dinitrate.- - - - - - - - - - ranking = 4keywords = radionuclide (Clic here for more details about this article) |