Magnetic resonance diagnosis of lipomatous hypertrophy of the atrioventricular grooves mimicking a tumour on echocardiography.

Echogenic structures in the atrioventricular grooves may cause diagnostic problems and may be misinterpreted as a tumour. Images of lipomatous hypertrophy of the atrioventricular grooves diagnosed by magnetic resonance but mimicking a tumour on echocardiography are presented.

Exercise myocardial perfusion and wall motion imaging to predict recurrence of angina pectoris after successful angioplasty.

OBJECTIVES: This study investigates the predictive value of concurrent exercise radionuclide ventriculography and myocardial perfusion scintigraphy obtained six weeks after successful percutaneous transluminal coronary angioplasty for the recurrence of angina. METHODS: Both studies were obtained simultaneously with a single injection of technetium-99m sestamibi using the first-pass technique and the computerized tomographic technique, respectively. Ninety-five patients were investigated at rest and at maximal exercise 6 weeks after technically successful coronary angioplasty. RESULTS: Exercise-induced left ventricular dysfunction was present in 44 patients (46%). Exercise-induced myocardial perfusion defects were noted in 29 patients (30%). All patients underwent a six months follow-up. Seventeen patients (18%) had recurrent angina pectoris. Exercise-induced left ventricular dysfunction at six weeks after angioplasty was significantly associated with the recurrence of angina (p = 0.002), but exercise-induced perfusion defects were not. An abnormal left ventricular response to exercise was more sensitive than exercise-induced perfusion defects (82% versus 47%) to identify those patients with recurrent angina. The combination of both tests allows to select patients at a very high (40%) and very low (7%) risk of recurrent angina. CONCLUSION: Exercise-induced left ventricular dysfunction is more strongly associated with the recurrence of angina pectoris during a 6 month follow-up than are exercise-induced myocardial perfusion defects.

Regional diastolic wall motion dynamics in anterior myocardial infarction: analysis and quantification with magnetic resonance imaging.

BACKGROUND: Regional variability in systolic and diastolic cardiac function occurs in most cardiac disorders. The influence of this regional functional heterogeneity on global function is not well understood and is difficult to study with the common imaging modalities. METHODS: A midventricular short axis slice of the left ventricle was obtained with ECG-triggered magnetic resonance imaging in eight infarct patients and 10 control volunteers. The variation in wall thickness and slice cavity volume during the cycle was studied using the centreline method. RESULTS: The peak filling rate was significantly decreased in the infarct group (96 versus 58 cm3/s, P < 0.005). In addition, a small contribution of other parameters, such as the time to end systole, the isovolumic relaxation time, and the duration and extent of early filling, was also shown by linear discriminant analysis. Analysis of the regional parameters demonstrated an increased asynchronicity of contraction (64 versus 37 ms, P < 0.01) as well as relaxation (88 versus 51 ms, P < 0.01) in patients with myocardial infarction. On comparison of the anterior (infarcted) and inferior (non-infarcted) parts of the left ventricle, the difference was present only in the infarct region. CONCLUSION: Magnetic resonance imaging of the heart allows evaluation of the relationship between regional differences in wall motion dynamics and global parameters of diastolic function in infarct patients.

Low-dosage dobutamine magnetic resonance imaging as an alternative to echocardiography in the detection of viable myocardium after acute infarction.

The objective of this study was the evaluation of the feasibility of magnetic resonance (MR) imaging of the heart with low-dosage dobutamine stimulation for the detection of viability after acute myocardial infarction. Gradient echo MR images were obtained in 37 patients with recent myocardial infarction. Images of wall motion abnormalities and their reaction to low-dosage dobutamine stimulation were analyzed and compared with two-dimensional echocardiograms. Follow-up echocardiography at 3 to 6 months was available in 24 patients. Concordant diagnosis of viability between the two techniques was obtained in 30 (81%) of 37 patients. MR correctly predicted evolution of wall motion in 19 (79%) of 24 patients, a result not significantly different from echocardiography: 20 (83%) of 24. It was concluded that low-dosage dobutamine MR imaging is a safe alternative to echocardiography to predict recovery of wall motion abnormalities after myocardial infarction.