Carlos Oliveira Lima

Noninvasive prediction of transvalvular pressure gradient in patients with pulmonary stenosis by quantitative two-dimensional echocardiographic Doppler studies.

Recent studies suggest that maximal Doppler velocities measured within the jets that form downstream from stenotic valves can be used to predict aortic valve gradients. To test whether the Doppler method would be useful for evaluation and management of pediatric patients with right ventricular outflow obstruction, we evaluated pulmonary artery flow before catheterization in 16 children with pulmonary valve stenosis. We used a 3.5-MHz, quantitative, range-gated, two-dimensional, pulsed, echocardiographic Doppler scanner with fast Fourier transform spectral output and a 2.5-MHz phased array with pulsed or continuous-mode Doppler. Peak systolic pulmonary artery flow velocities in the jet were recorded distal to the domed pulmonary valve leaflets in short-axis parasternal echocardiographic views. The pulsed Doppler scanner, because of its limitations for resolving high velocities, could quantify only the mildest stenoses; but, especially with the continuous Doppler technique, a close correlation was found between maximal velocity recorded in the jet and transpulmonary gradients between 11 and 180 mm Hg. A simplified Bernoulli equation (transvalvular gradient = 4 X [maximal velocity]2) proposed by Hatle and Angelsen could be used to predict the gradients found at catheterization with a high degree of accuracy (r = 0.98, SEE = + 7 mm Hg). Our study shows that recording of maximal Doppler jet velocities appears to provide a reliable measure of the severity of valvular pulmonic stenosis.

Clinical utility of two-dimensional doppler echocardiographic techniques for estimating pulmonary to systemic blood flow ratios in children with left to right shunting atrial septal defect, ventricular septal defect or patent ductus arteriosus.

Range gated two-dimensional Doppler echocardiographic methods were evaluated for quantifying pulmonary (QP) to systemic (QS) blood flow ratios. Twenty-one patients were studied, 4 with patent ductus arteriosus, 6 with atrial septal defect and 11 with ventricular septal defect. The Doppler pulmonary to systemic flow (QP:QS) estimation method involved calculating volume flow (liters/min) at a variety of intracardiac sites by using imaging information for flow area and Doppler outputs to calculate mean flow velocity as a function of time. Area volume flows were combined to yield QP:QS ratios. The sites sampled were main pulmonary artery, ascending aorta, mitral valve orifice and subpulmonary right ventricular outflow tract. The overall correlation between Doppler QP:QS estimates and those obtained at cardiac catheterization (n = 18) or radionuclide angiography (n = 3) was r = 0.85 (standard error of the estimate = 0.48:1). These preliminary results suggest that clinical application of this Doppler echocardiographic method should allow noninvasive estimation of the magnitude of cardiac shunts.

Prediction of the severity of left ventricular outflow tract obstruction by quantitative two-dimensional echocardiographic Doppler studies.

In this study we explored the use of continuous wave Doppler echocardiography guided by simultaneous two-dimensional echocardiographic imaging as a method for noninvasively estimating pressure gradients in patients with discrete forms of left ventricular outflow tract obstruction. We studied 16 children, ages 6 months to 17 years, with valvular aortic stenosis (n = 12) or with discrete subaortic stenosis (n = 4) and compared maximal Doppler velocities in the aorta with pressure gradients obtained at cardiac catheterization. Examinations could be performed from the suprasternal notch view or from the apical left ventricular outflow tract view with equal accuracy for the study of flow in the left ventricular outflow tract, and results were comparable in both views. With a simplified Bernoulli relationship (gradient = 4 X [maximal velocity]2), results suggested that Doppler echocardiography could be used to predict the severity of obstruction in our patients with a correlation coefficient of r = .94 (SEE +/- 7.5 mm Hg) between Doppler-estimated gradients and gradients obtained at catheterization. The method appears promising for initial evaluation and for serial management of patients with discrete forms of left ventricular outflow tract obstruction.

Normal intracardiac and great vessel doppler flow velocities in infants and children

Normal two-dimensional pulsed Doppler echocardiographic velocity profiles for sites within the heart and great vessels in a group of 102 normal infants and children are presented. Qualitatively, waveforms mimic expected hemodynamic events at the various sites. All waveforms had a rapid initial deflection followed by spectral broadening after attainment of peak velocity. Quantitative angle-corrected peak velocities were generally lower on the right side than on the left side of the heart. Differences in tricuspid (mean 61.8 cm/s) versus mitral (mean 81.1 cm/s) outflow and pulmonary (mean 76.1 cm/s) versus aortic (mean 88.5 cm/s) outflow were significant (p less than 0.01). The only significant age-related differences were in the pulmonary artery (mean for newborns 67.7 cm/s versus 79.6 cm/s for older children, p less than 0.01). Aortic data obtained from interrogation sites in which flow was close to 0 or 180 degrees were similar, whereas aortic peak velocity data obtained from apical long-axis or subcostal views were greater. These differences were probably induced from inaccuracies in azimuthal (elevational) angles that cannot be measured. These normal Doppler data should be useful for comparisons with data obtained for children with various forms of congenital heart disease that affect flow dynamics.

Prognostic value of left ventricular size measured by echocardiography in infants with total anomalous pulmonary venous drainage

Abstract Left ventricular size may be a determinant of survival in infants with total anomalous pulmonary venous drainage. Right and left ventricular size were measured by M-mode and 2-dimensional (2-D) echocardiography in 13 patients aged 1 day to 4 months (mean weight 4.3 ± 0.42 kg [standard error of the estimate]) who underwent surgery before age 4 months because of severe cyanosis or cardiac failure. Seven patients had venous drainage to a vertical vein, 4 had drainage to the right atrium, and 2 had drainage to the inferior vena cava. Patients were divided into 2 groups: survivors (Group A, n = 8) and nonsurvivors (Group B, n = 5). Death was not statistically related to pulmonary artery pressure, pulmonary venous obstruction, age, or weight at the time of surgery. Right and left ventricular sizes at end-diastole measured from M-mode traces and 2-D echocardiographic 4-chamber views were compared with those from 15 weight-matched control infants. On M-mode and 2-D echocardiography, nonsurvivors had significantly larger right ventricles and smaller left ventricular dimensions than did either control subjects or surviving patients with total anomalous pulmonary venous drainage. The ratio of right to left ventricular size on M-mode and 2-D echocardiography also differed among the 3 infant groups (p

Two-dimensional echocardiography for evaluation of metastatic cardiac tumors in pediatric patients.

We have studied five patients with metastatic cancer in whom two-dimensional echocardiography (2DE) demonstrated cardiac or pericardial involvement. Echo studies may guide the clinician in instituting and/or modifying cardiac and cancer therapy in such patients.

Two-dimensional echocardiographic study of right ventricular outflow and great artery anatomy in pulmonary atresia with ventricular septal defects and in truncus arteriosus

In this study, we reviewed M-mode and two-dimensional (2DE) echocardiographic observations in 13 patients with pulmonary atresia with ventricular septal defect and in six patients with truncus arteriosus in order to attempt to identify echocardiographic features distinguishing these two abnormalities in which no anatomic connection exists between the right ventricle and the pulmonary artery. M-Mode features compatible with the diagnosis of pulmonary atresia with a ventricular septal defect (VSD) were a small but identifiable space anterior to the aorta and/or immobile pulmonic valve echoes appearing to open during diastole rather than systole. By 2DE, the proximal and distal segments of the right ventricular outflow tract could be imaged and the length of the atretic segment estimated. In truncus arteriosus, no outflow tract of the right ventricle could be identified by 2DE or M-mode echocardiography, and the origin of the pulmonary artery from the truncus could be imaged directly in four patients with type I and in one patient with type II truncus. Abnormalities of the truncal valve were also present and were imaged by 2DE in three of our five patients. Our study identified specific echocardiographic criteria for diagnosing truncus arteriosus and pulmonary atresia with VSD and for differentiation between them.

Serial two-dimensional echocardiography for detection of coarctation of the aorta in the postnatal period

SummaryWe describe the ultrasound appearance of postnatal development of an angiographically proven coarctation of the aorta in a full-term infant. The diagnosis of a discrete coarctation was subsequently supported on a repeat two-dimensional echocardiogram, after an initial clinical and two-dimensional study at 6 h of age that had revealed only minimal juxtaductal aortic deformity. We stress the importance of two-dimensional echocardiography as a reliable noninvasive method for detecting the change in aortic contour occurring with ductal closure in infants with predisposing aortic anatomy who will go on to develop coarctation of the aorta.

Left ventricular wall motion abnormalities in Kawasaki's disease

Two-dimensional (2DE) and M-mode echocardiographic examinations were reviewed for 21 patients with Kawasakis disease. Cardiac catheterization including coronary angiography was performed in 14 patients. 2DE detected regional myocardial contraction deficits in four patients later proven to have coronary disease. Coronary aneurysms were detected by echocardiography in two of four patients with proven coronary lesions. Although a minor pericardial effusion was detected in two patients and an increased left ventricular (LV) cavity dimension was found in one patient, M-mode function studies were not helpful for detection of cardiac involvement. ECG and chest x-ray examination were also noncontributory. We conclude that 2DE detection of LV wall contraction abnormalities may be a sensitive method for detecting cardiac contraction abnormalities may be a sensitive method for detecting cardiac involvement in Kawasakis disease. 2DE may be better for assessing LV contraction than for imaging aneurysms in Kawasaki patients.