No abstract

To evaluate the applicability of two-dimensional echocardiography to left ventricular volume determination, 30 consecutive patients undergoing biplane left ventricular cineangiography were studied with a wide-angle (84 degrees), phased-array, two-dimensional echocardiographic system. Two echographic projections were used to obtain paired, biplane, tomographic images of the left ventricle. We used the short-axis view (from the precordial window) as an anolog of the left anterior oblique angiogram, and the long-axis, two-chamber view (from the apex impulse window) as a right anterior oblique angiographic equivalent. A modified Simpson's rule formula was used to calculate systolic and diastolic left ventricular volumes from the biplane echogram and the biplane angiogram. These methods correlated well for ejection fraction (r = 0.87) and systolic volume (r = 0.90), but only modestly for diastolic volume (r = 0.80). These correlations are noteworthy because 65% of the patients had significant segmental wall motion abnormalities. The volumes determined from the minor-axis dimensions of M-mode echograms in 23 of the same patients correlated poorly with angiography.

A new, rapid magnetic resonance (MR) imaging method, cine MR imaging, was used to determine the regurgitant fraction (RF) in patients with left-sided regurgitant lesions. Right and left ventricular stroke volumes were determined with cine MR imaging and a modified Simpson formula in ten healthy volunteers and 23 patients known to have either predominant mitral (n = 17) or aortic (n = 6) regurgitation. RFs evaluated at cine MR imaging were compared in healthy persons and patients with mild, moderate, or severe regurgitation demonstrated at angiography (n = 10) and Doppler echocardiography (n = 13). Cine MR imaging depicted regurgitant blood flow in all 29 regurgitant lesions in 23 patients as areas of low signal intensity within the regurgitant chamber. The RF was 4% +/- 7% in healthy subjects and 12% +/- 12% in those with mild, 35% +/- 14% in those with moderate, and 63% +/- 5% in those with severe regurgitation. The RFs determined by two observers were similar.

Gated magnetic resonance (MR) imaging was used to evaluate central cardiovascular anatomy in 172 subjects, 31 of whom were healthy volunteers. Using the spin-echo technique, images of diagnostic quality were obtained in 93% of cases with TE = 28 msec and in 65% of cases with TE = 56 msec. Transverse multisection sequences encompassing most of the left ventricle required approximately 6-8 minutes. Corroborative studies were available in 134 of 141 patients who had cardiovascular disease; two dimensional echocardiograms and angiography in 133 and 100 patients, respectively. Gated MR demonstrated the wall thinning and complications caused by prior myocardial infarctions and high signal intensity of the myocardium at the site of acute myocardial infarctions. MR accurately demonstrated anatomic abnormalities owing to hypertrophic and congestive cardiomyopathies, congenital abnormalities of the heart and great vessels, rheumatic heart disease, pulmonary hypertension, and cardiac and paracardiac masses. Depiction of cardiovascular anatomy and pathoanatomy was attained without the use of any contrast media. Consequently, gated MR is an effective technique for cardiac diagnosis. The short time required for tomographic examination of the entire heart using the multisection technique renders this a practical cardiac imaging modality.

With the technical assistance ofPatricia A. Hart, M.A., R.D.M.S.SUMMARY We have evaluated apex echocardiography, using an 800 phased array sector scanner, in 368 patients with congenital heart disease. With the patient lying with the left side dependent, the transducer is placed over the apex of the heart and cross sectional images are obtained in the plane perpendicular to the cardiac septa and through the orifices of the mitral and tricuspid valves. In this view, the chambers are side by side and both atria and ventricles are separated by their respective septa and atrioventricular valves. Defects in the region of the septa can be detected. Congenital defects involving the atrioventricular valves, such as endocardial cushion defects, tricuspid TWO-DIMENSIONAL phased array sector scanners allow high resolution imaging of large cross sections of the heart from small echocardiographic windows. Conventionally, precordial window transducer placement has been used to produce the images."'' Alternative transducer application in the suprasternal notch,20 over the cardiac apex21 and subxyphoid areas allows alternative approaches for obtaining tomographic images of cardiac chambers. Using an 800 phased array sector scanner, we have used the apex as a locus from which to display simultaneously the four cardiac chambers, the atrioventricular valves, and the cardiac septa. Because of this unique presentation, this view has been useful in defining a wide variety of congenital heart defects. atresia, and Ebstein's anomaly, can be defined. The location of the baffle after Mustard's operation for aortopulmonary transposition and intra-atrial structures, such as the membrane in cor triatriatum, can be seen. The position of the apex of the heart can be located in dextro, levo, or mesocardia by definition of the apex image. The relative size of the cardiac chambers can be compared. The localized thickness of the ventricular septum can be identified with the apex image. We have found this technique to be valuable in patients with congenital heart disease who are undergoing cross sectional echocardiography. Methods PatientsWe examined 368 patients, with ages ranging from newborn to adult, who had congenital heart disease. Apical cardiac images were performed as part of the two-dimensional echocardiographic examination. The diagnosis was established at cardiac catheterization in 218 of these patients. In the remainder, the diagnosis was made by clinical means, electrocardiography, roentgenography, and M-mode echocardiography. Examination TechniquesThe recording of the apical image requires precise positioning of the patient and application of the transducer to produce an optimal image ( fig. la and b). The subject is positioned as for performance of an apexcardiogram, lying supine with the left side of the thorax dependent. When the cardiac apex is difficult to palpate, the transducer is applied to the apex region and moved around in this region until the precise image is obtained with the apex of the heart in the apex of the image....