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Biomedical subjects

D J Sahn

Publications and source records attributed to D J Sahn.

At least 199 records · Page 11Linked to original sources
PubMed1984

Endomyocardial biopsy with fluoroscopic and two-dimensional echocardiographic guidance: case report of a patient suspected of having multiple cardiac tumors.

An 18-year-old female with multiple intracardiac masses was further evaluated using percutaneous endomyocardial biopsy of the right ventricle and right atrium. Fluoroscopy was used to visualize the course of the bioptome and simultaneous two-dimensional echocardiography was used to image the masses thus improving the surgeon's chance of obtaining diagnostic tissue.

Adolescent↗
PubMed1984

Digital subtraction angiography of the aortic arch.

We evaluated the utility of intravenous digital subtraction angiography (IV DSA) for diagnosing lesions of the aortic arch and great vessels in 25 patients. Digital subtraction angiography (DSA) was found useful in evaluating congenital and acquired lesions of the arch and great vessel origins, and it proved adequate for follow-up of patients who had graft replacement. Cases examined included: right aortic arch, double arch, aortic coarctation, aberrant vascular origins, aortic aneurysm and pseudoaneurysm, changes in atherosclerotic great vessels, and revascularization procedures for patients with pulmonary atresia and aortic interruption. In our experience, DSA is a useful tool for screening and following patients with aortic arch or great vessel lesions; it is often the only diagnostic imaging examination necessary.

Adult↗
PubMed1984

Two-dimensional echo Doppler study of congenital disorders of the mitral valve.

To define the use of two-dimensional echocardiography (2DE) and Doppler methods for diagnosis of forms of congenital mitral stenosis, we studied 16 children, age range 2 months to 13 years, with congenital deformities of the mitral valve documented at cardiac catheterization. Thirteen had additional congenital heart defects, most commonly aortic stenosis or aortic coarctation. In eight patients features of mitral valve anatomy were observed and described during cardiac surgery and in one child the anatomy was verified by postmortem examination. 2DE studies allowed anatomic subclassification of 10 valves which had asymmetric or single dominant papillary muscles (parachute) and six which had arcade mitral valve attached by short chords to multiple diminutive papillary muscle heads. All patients' echoes exhibited shortened and thickened mitral chordae and doming of the mitral leaflets during diastole, and seven children had restricted mitral orifices imaged on the short-axis imaging plane. All seven of the patients studied by Doppler echocardiography had increased maximal transmitral inflow velocity (range 111 to 260 cm/sec) greater than the 95% confidence limits for mitral flow velocities in 34 normal children who served as the control group. Our study suggests that 2DE studies, especially when combined with Doppler interrogation, are sensitive for defining forms of congenital mitral stenosis.

Adolescent↗
PubMed1984

Left ventricular wall motion abnormalities in Kawasaki's disease.

Two-dimensional (2DE) and M-mode echocardiographic examinations were reviewed for 21 patients with Kawasaki's 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 Kawasaki's disease. 2DE may be better for assessing LV contraction than for imaging aneurysms in Kawasaki patients.

Aneurysm↗
PubMed1984

Anatomic-ultrasound correlations for intraoperative open chest imaging of coronary artery atherosclerotic lesions in human beings.

This study was performed to further validate a method for intraoperative ultrasound imaging of coronary arteries. Ultrasound images of coronary atherosclerotic lesions were compared with anatomic specimens of the coronary arteries obtained from open chest human subjects. The anatomic specimens were derived from four cardiac transplant recipients, accepted as candidates for transplantation because they had severe diffuse atherosclerotic disease, and one patient who died in the early postoperative period after a coronary artery bypass procedure. Twenty-six ultrasonically imaged atherosclerotic areas of the coronary arteries in these patients were compared with formalin-fixed and decalcified anatomic specimens. Specific ultrasound appearances for atherosclerotic lesions were observed, including 1) discrete (focal) stenosing fibrous/atheromatous plaques; 2) diffuse nonobstructive fibrous/atheromatous disease (detectable even in anatomically small vessels); 3) complete occlusion by fibrous/atheromatous lesions or organizing thrombus; and 4) "shadowing," an ultrasound pattern characteristic of significant calcification within atherosclerotic plaques. As part of this study, a new 12 MHz water path probe was evaluated for coronary artery scanning. The new probe allowed improved access to coronary arteries and increased detail of anatomic visualization. Both the performance of the new high resolution probe and the knowledge gained by the anatomic correlations obtained in this study should aid the development of intraoperative coronary artery scanning for surgical localization of atherosclerotic disease during coronary bypass surgery.

Adult↗
PubMed1984

Noninvasive quantification of stenotic semilunar valve areas by Doppler echocardiography.

Fourteen patients, aged 1 month to 13 years, with congenital semilunar valve stenosis (11 pulmonary and 3 aortic) were studied for orifice area quantification calculated from a Doppler echocardiographic equation: Area = SV/0.88 X V2 X VET, where SV = stroke volume, V2 = maximal velocity and VET = ventricular ejection time. Results from individual measurements used in this formula and derived area were compared with individual results from cardiac catheterization and valve area derived from the Gorlin formula. Ventricular ejection time by cardiac catheterization ranged from 0.17 to 0.44 second (mean +/- standard deviation [SD] 0.27 +/- 0.09), and by Doppler study from 0.20 to 0.41 second (mean +/- SD 0.29 +/- 0.06) (r = 0.65, standard error of the estimate [SEE] = 0.03, y = 0.149 + 0.528x). Pressure gradient by catheterization ranged from 30 to 125 mm Hg (mean +/- SD 56.6 +/- 33.1), and by Doppler study from 17.6 to 100 mm Hg (mean +/- SD 46.8 +/- 27.9) (r = 0.91, SEE = 8.8, y = 1.23 + 0.904x). Stroke volume was measured by Doppler study simultaneously with cardiac catheterization in nine patients; results at cardiac catheterization with thermodilution measurements (cardiac output/heart rate) ranged from 5.5 to 53.4 cc (mean +/- SD 24.7 +/- 20), and by Doppler study from 5.8 to 46.9 cc (mean +/- SD 23 +/- 18) (r = 0.96, SEE = 3.5). Area quantification was performed in two ways. In Group 1, heart rate-matched stroke volumes from cardiac catheterization were used in the derived equation for Doppler study (all patients). In Group 2, the stroke volume used was that obtained by Doppler study, which was performed simultaneously with cardiac catheterization (nine patients).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

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.

Adolescent↗
PubMed1984

Ultrasonic contrast studies for the detection of cardiac shunts.

Contrast echocardiography has achieved importance in the diagnosis of cardiac shunt lesions. The technique provides information about flow patterns and serves as an adjunct to identifying communications that may be too small to image, even with high resolution real time scanning. This report reviews clinical applications and experiences in the use of standard, peripherally injected echocardiographic contrast agents for the detection of atrial septal defect, ventricular septal defect and patent ductus arteriosus. The importance and development of transpulmonary contrast agents capable of crossing the pulmonary capillary bed to opacify the left ventricle are reviewed and experience with a variety of experimental echocardiographic contrast agents is presented. Agents opacifying the left ventricle after intravenous injection are capable of providing direct ultrasonic contrast imaging of congenital left to right shunts. Further, recent experience with an experimental standardized, gas-producing contrast agent in an open chest animal model with an experimentally produced ventricular septal defect suggests that a combination of an experimental right heart agent that produces a measurable and reproducible amount of contrast effect, with a videodensitometric system capable of quantifying both positive and negative contrast effects, may provide an ultrasonic method for evaluating the magnitude of cardiac shunts.

Animals↗
PubMed1984

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.

Adolescent↗
PubMed1984

A pulsed Doppler echocardiographic method for calculating pulmonary and systemic blood flow in atrial level shunts: validation studies in animals and initial human experience.

The purpose of this study was to assess the accuracy of a quantitative two-dimensional range-gated Doppler echocardiographic method for estimating systemic and pulmonary flows in an open-chest canine preparation with a variable-sized atrial level shunt mimicking an atrial septal defect. In addition, we also report our initial experience with 10 children who had isolated atrial septal defects and who had pulmonary and systemic flow rations (QP:QS) determined by Doppler echocardiography simultaneously with green dye-shunt calculations in the cardiac catheterization laboratory. Ten mongrel dogs weighing 20 to 30 kg were anesthetized, intubated, and mechanically ventilated. Previously calibrated electromagnetic flow probes were placed around the ascending aorta and main pulmonary artery, and an atrial level shunt was created by inserting one-half inch diameter cannulae into the left and right atrial appendages and connecting both cannulae to 3/4 inch tubing that passed through a previously calibrated extracorporeal mechanical roller pump. This permitted quantitation as well as regulation of shunt size and direction. With each step-by-step variation in shunt magnitude, systemic and pulmonary flows were estimated by Doppler echocardiography and were matched to the simultaneous electromagnetic flowmeter recordings. Doppler-estimated systemic blood flow was obtained by imaging and recording Doppler flow velocities in the ascending aorta with the transducer positioned directly over the vessel. Doppler pulmonary flow was obtained by imaging the main pulmonary artery on the short-axis view and by determining flow velocity with the sample volume placed distal to the pulmonic valve.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Validation of a Doppler echocardiographic method for calculating severity of discrete stenotic obstructions in a canine preparation with a pulmonary arterial band.

The purpose of this study was to develop an open-chest animal preparation to validate the accuracy of a two-dimensional Doppler echocardiographic method for estimating pressure drops across discrete stenotic obstructions. Six mongrel dogs underwent median sternotomy and catheters were placed in the right ventricle, distal main pulmonary artery, and aorta of each. A 1/8 inch umbilical tape was sewn to the posterior rim of the pulmonary artery just above the anulus and was progressively tightened to vary the degree of stenosis. Ultrasound and Doppler studies were performed with a 2.5 MHz phased-array unit with capabilities for pulsed or continuous-mode Doppler and real-time imaging. Peak systolic main pulmonary arterial flow velocities were recorded by Doppler echocardiography within the jet distal to the band from an oblique parasternal short-axis echocardiographic view and corrected for angle of incidence between the direction of Doppler sampling and the presumed direction of flow. Doppler velocities were converted to gradients with a simplification of the Bernoulli equation (gradient = 4 X maximal Doppler flow velocity2 ). Maximal Doppler-determined systolic pulmonary arterial velocities showed a good linear correlation with the 63 measured pressure drops (r = .95, SEE +/- 36.3 cm/sec). An excellent correlation was also found between Doppler-calculated and actual pressure gradients (r = .96, SEE +/- 7.26 mm Hg). Our results suggest that this Doppler method for measuring gradients across discrete stenotic obstructions may be quite accurate in clinical applications.

Animals↗
PubMed1983

Two-dimensional echocardiographic evaluation of dilated cardiomyopathy in children.

This study examines and quantitates left ventricular (LV) short-axis 2-dimensional (2-D) echocardiograms of 16 normal control subjects and 19 patients who presented with clinical features suggestive of myocarditis leading to severe myocardiopathy. Of the 19 patients, 8 died or had cardiac transplantation: 9 were studied in the chronic phase and 10 in the acute phase. The endocardial surface of the LV short-axis image was digitized at chordal level at end-diastole and end-systole. Digitized traces in systole and diastole were superimposed. The cavity area of systole and diastole was determined and expressed as the percent systolic area reduction ratio. In the control subjects, the left ventricles were round in systole and diastole, contracted concentrically, and had a mean percent systolic area reduction of 53% (range 43 to 67). The left ventricle was not round in systole in the patients with myocarditis, and in 15, only the ventricular septum contracted significantly. Three patients had nonconcentric contraction, and regional contraction was more difficult to judge. The systolic area reduction ratio for the patients was 11% (range 1 to 33), with no overlap with control subjects (p less than 0.001). Our results suggest that myocarditis more severely affects the LV free wall than the septum. In chronic patients, LV contraction remained markedly impaired. Quantitative evaluation of short-axis 2-D echocardiograms is a useful and sensitive technique for assessing damage due to presumed myocarditis.

Adolescent↗
PubMed1983

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.

Child↗