American journal of cardiac imaging最新文献

We report the case of a 58-year-old woman who underwent outpatient coronary angiography with 5F catheters for atypical chest pain. Superselective angiography of a right superior septal artery mimicked a coronary arteriovenous fistula. Appropriate placement of the catheter in the ostium of the right coronary artery excluded the suspected anomaly.

Two-dimensional (2-D) echocardiography is an effective method for determination of left ventricular (LV) mass in patients with normal or abnormal LV geometry. Two geometric approaches have been validated and are recommended by the American Society of Echocardiography: an area-length approach and a truncated ellipsoid geometry. Both rely on short-axis imaging for determining myocardial cross-sectional area. Whereas M-mode LV mass has been widely used in hypertension, where LV geometry is usually normal, 2-D echocardiography LV mass has been applied less widely. Recent developments in echocardiography will further enhance the utility of these methods, including three-dimensional uses of 2-D echocardiographic data, automatic edge detection, and multiplanar transesophageal imaging.

To compare modern, digital exercise echocardiography and thallium 201 single-photon emission computed tomography (SPECT) in patients with unstable coronary artery disease, 65 men unselected with regard to echocardiography were prospectively investigated 1 month after an episode of unstable angina or non-Q-wave myocardial infarction. Exercise echocardiography and 201Tl SPECT were performed on consecutive days in connection with a standard symptom-limited upright bicycle test and analyzed in a 9-segment model. Coronary angiography was performed in all but 1 patient and 60 patients had significant coronary lesions. Wall motion abnormalities were seen in 53 patients (81%) at rest and perfusion defects in 57 patients (88%) at the redistribution images. New or worsening of wall motion abnormalities were seen in 55 patients, either seated at peak exercise or recumbent after exercise, and 43 patients had reversible or partially reversible 201Tl scintigraphic defects (P = .02). The segmental agreement between wall motion abnormalities and scintigraphic defects was low (58%). The additional value of exercise echocardiography and 201Tl SPECT to exercise test was greatest in patients with one-vessel disease. Thus, 1 month after an episode of unstable coronary artery disease in men, there is a high incidence of significant coronary stenoses as well as signs of ischemia shown both by wall motion abnormalities during exercise echocardiography and by postexercise studies with 201Tl SPECT. Exercise echocardiography gives a higher diagnostic yield regarding occurrence of reversible ischemia.

Left ventricular hypertrophy, manifested as an increase in left ventricular mass, is commonly seen as a response to heart disease of various etiologies. Regression of hypertrophy may serve as a gauge to the efficacy of treatment. Although many methods are available for determination of mass, most of these either visualize the heart in limited numbers of planes and therefore require that assumptions about left ventricular shape be made, or are dependent on homogeneous myocardial perfusion. These assumptions may be invalid in disease status. Magnetic resonance imaging allows high-resolution visualization of the entire heart, and therefore, accurate measurement of left ventricular mass, in a fashion that does not depend on shape or perfusion. This is the method of choice for mass determination in clinical investigations and for serial evaluation of selected patients.

In validation studies, M-mode echocardiography has been shown to measure left ventricular (LV) mass with reasonable accuracy (r > or = .90 v necropsy measurements) in species ranging in body size from humans to rats. The sensitivity of antemortem echocardiography for the detection of necropsy LV hypertrophy as a qualitative abnormality has also been high (85% to 100%). Increased LV mass is strongly related to both increased blood pressure and to being overweight or to other causes of increased cardiac volume work. LV mass is also increased in the presence of exaggerated blood pressure responses to everyday activity, high sodium intake and blood viscosity, and genetic factors predisposing to hypertension. Indexation of LV mass by body surface area or height has advantages for the detection of hypertrophy related to hypertension or obesity. Indexation of LV mass for the power of its relation to height (2.7) revealed by analysis of growth (allometric) relations may accomplish both these goals. Recent research indicates that the level of LV mass measured by M-mode echocardiography is a stronger predictor of subsequent morbid events and death than blood pressure or other conventional risk factors except age. Preliminary findings of close relations between LV mass and arterial disease and between the change in LV mass during antihypertensive treatment and subsequent events contribute to explaining the strong predictive value of LV mass.

RNA has clinical applications in virtually all forms of acquired heart disease and is also useful in the detection and quantitation of congenital left-to-right shunts. The method has achieved widespread acceptance for the qualitative and quantitative assessment of systolic ventricular function. It is also particularly well suited for identifying abnormal diastolic filling patterns typical of hypertrophic and ischemic heart diseases. To date, no single variable from any noninvasive or invasive procedure has been shown to have greater prognostic importance than the radionuclide exercise ejection fraction in patients with CAD.