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Biomedical subjects

R Gramiak

Publications and source records attributed to R Gramiak.

At least 19 recordsLinked to original sources
PubMed1989

Left ventricular thrombus and systemic emboli complicating the cardiomyopathy of Duchenne's muscular dystrophy.

A 17-year-old boy with Duchenne's muscular dystrophy and congestive cardiomyopathy with a left ventricular thrombus is described. The patient presented with flank pain, and computed tomography of the abdomen revealed multiple bilateral renal infarcts. An echocardiogram delineated a left ventricular thrombus and generalized hypokinesis with a left ventricular ejection fraction of 25%. Heparin therapy was started, but the patient died of refractory congestive heart failure. Autopsy revealed diffuse skeletal myopathy consistent with Duchenne's muscular dystrophy as well as biventricular cardiomyopathy with a recent left ventricular apical-septal mural thrombus. Right atrial thrombus, a left upper lobe pulmonary embolus, and splenic and renal infarcts were also noted. To our knowledge, this is the first reported case of left ventricular thrombus with or without systemic emboli in the cardiomyopathy of Duchenne's muscular dystrophy.

Adolescent↗
PubMed1987

Doppler ultrasound in aortic stenosis: in vitro studies of pressure gradient determination.

Torricelli's equation expresses a simple relationship between fluid velocity and pressure gradient in orifice flow and is currently used in conjunction with noninvasive Doppler ultrasound to determine gradients in mitral stenosis, and aortic stenosis, as well as other cardiovascular orifices. In theory, however, the Torricelli equation overestimates the gradient in aortic stenosis and the Borda equation should be more applicable. A brief tutorial derivation of the Borda and Torricelli equations is presented. The applicability of Torricelli's equation in aortic stenosis was studied experimentally with a rigid wall, pulsatile flow analogue. Doppler ultrasound and manometric data were collected simultaneously. Percent stenosis, peak flow rate and fluid viscosity were varied. The results demonstrated that the Torricelli equation consistently overestimated the pressure gradient. At 61% area stenosis, the overestimation exceeded 100%. In vivo studies are required to determine the relevance of the observations to clinical situations.

Aortic Valve Stenosis↗
PubMed1986

Left coronary arterial blood flow: noninvasive detection by Doppler US.

Continuous wave (CW) and pulsed Doppler ultrasound studies with spectral analysis were used to detect the left coronary arterial blood flow in patients who were undergoing routine echocardiography. The pulmonary artery is a stable ultrasonic landmark from which detection of the blood flow can be effected. The left coronary artery can be distinguished by its blood flow toward the cardiac apex and by specific, functional flow features. Flow patterns vary among the left main, circumflex, and anterior descending arteries; patterns also vary with respiration cycles. In the present study, coronary arterial blood flow was detected in 58 of 70 patients (83%). Findings were validated by selectively injecting an agitated saline contrast medium into the left coronary artery and, in another study, by comparing human Doppler phasic flow waveforms with electromagnetic flowmeter recordings obtained in dogs.

Animals↗
PubMed1984

Is routine angiography necessary prior to carotid endarterectomy?

The records of 111 consecutive patients undergoing evaluation for possible carotid endarterectomy at the University of Rochester were reviewed. All patients had noninvasive evaluation (oculoplethysmography-Gee and direct, continuous-wave Doppler ultrasonography) as well as selective carotid angiography. Patients were grouped by clinical presentation to ascertain the relative importance of angiography in determining the need for surgery. Arteriography added nothing to clinical and noninvasive evaluation in over two thirds of patients with hemispheric cerebral symptoms or asymptomatic carotid bruits. In contrast, we found that almost all patients with nonhemispheric symptoms required angiography for adequate evaluation prior to surgery. The implication of these findings on preoperative evaluation of patients with carotid surgery is discussed.

Angiography↗
PubMed1982

Frequency-dependent angle scattering of ultrasound by liver.

Ultrasonic scattering by one specimen of normal pig liver and two specimens of abnormal human liver has been measured as a function of angle and frequency at each angular position of transmit and receive transducers which were rotated in equal and opposite directions about the axis of a cylindrically shaped tissue sample. Mean data values were determined by averaging points at like frequencies and angular positions in scans made at intervals along the axis of the specimen. Sections of the specimens were obtained throughout its length and stained to emphasize structures containing collagen and connective tissue shown by acoustic microscopy to produce sound speed variations which are known to cause scattering. Using the stained sections as diffraction screens, calculations of scattering were carried out via Fourier transforms on a scale comparable to that in the acoustic studies for comparison with the acoustic data. In all specimens studied, mean acoustic scattering exhibited a general decrease in level with increasing scattering angle. The rate of decrease in acoustic scattering with angle agreed qualitatively with the calculations of average angular falloff of scattering by the stained sections. Lower rates of decrease were observed in tissues with more closely spaced collagen containing structures. Although the data derived from the few substantially different specimens studied is not intended to be representative of all liver, the results show a qualitative correspondence between acoustic scattering and visual appearance which depends on tissue components and their arrangement.

Animals↗
PubMed1981

Automated water-path ultrasonic examination of scrotum.

A new method of examining the scrotum by ultrasound with an automated water-path scanner is described. This method allows immobility of the scrotum in a more acceptable and painless way than in contact scanning methods. Panoramic scans of the entire scrotum and precision tomographic plane placement are advantages over conventional techniques. A description of normal scrotal anatomy includes the mediastinum of the testis, an important scrotal landmark. Representative cases of benign and malignant scrotal disease are presented to emphasize the utility of water-path scanning.

Adolescent↗
PubMed1980

Echocardiographic evaluation of cardiac abnormalities in Duchenne's dystrophy and myotonic muscular dystrophy.

Routine echocardiographic examinations were performed on 53 individuals with muscular dystrophy (29 with myotonic muscular dystrophy [MMD] and 24 with Duchenne's dystrophy [DD]). Five of 29 (17%) with MMD and six of 24 (25%) with DD had typical mitral valve prolapse evidenced by echocardiography. All patients with DD and mitral valve prolapse had severe thoracic skeletal deformities, while none with MMD and mitral valve prolapse had such abnormalities. Other echocardiographic parameters analyzed included the fractional shortening of the left ventricle (% delta S), excursions of the left ventricular posterior wall (LVPW) and the ventricular septum, pre-ejection period/left ventricular ejection time ratios (PEP/LVET), and thickness of the LVPW and ventricular septum. Abnormal prolongation of the PEP/LVET ratio and increased thicknesses of the LVPW and ventricular septum were noted in some individuals in the MMD group. Decreased % delta S with diminished excursion and diastolic velocity of the LVPW were noted in some with DD.

Adolescent↗
PubMed1979

Echogenic fluid: a pitfall in the ultrasonographic diagnosis of cystic lesions.

Although it is well known that biliary sludge can produce fine diffuse echoes within the gallbladder, it is less commonly appreciated that other cystic structures may contain echogenic fluid and therefore be mistaken sonographically for solid lesions. In this article three cases of splenic cysts and one case each of pyrometrocolpos, hydroureter, and pyonephrosis presented with diffuse fine echoes in the fluid. Three of these cases were misinterpreted as a result of this echogenic appearance. These cases serve to emphasize the need for awareness of the echogenicity of some types of fluid and the value of other signs of cystic lesions besides absence of internal echoes.

Adult↗
PubMed1979

Ultrasonic detection of myocardial infarction by amplitude analysis.

Myocardial infarctions were produced in dogs by occluding the left anterior descending artery; the dogs were killed at varying times, from 30 minutes to 8 days. Prior to sacrifice, Thioflavin S was injected intravenously. The excised heart was scanned by a B-scanner interfaced with a computer that permitted quantification of signal amplitude. The heart was sectioned, photographed, and studied pathologically. Infarcted myocardium showed high ultrasonic reflectivity with average amplitudes 1.4--2.6 times that of normal muscle. Perfusion-histomorphologic evidence of infarction correlated best in infarcts of 24 hours or less; older infarcts were generally underestimated. Tissue changes, sources of false-positive and false-negative findings, signal processing, and potential clinical utility are discussed.

Animals↗
PubMed1979

New techniques in cardiac imaging with ultrasound: state of the art.

Two-dimensional real-time ultrasonic imaging in the diagnosis of acquired and congenital cardiac lesions is reviewed. This technique provides anatomically correct cross-sectional images and demonstrates movements of valve leaflets and segments of heart walls. The imaging of blood flow through the use of ultrasonic contrast agents and the application of pulsed Doppler principles is also reviewed, and future trends are discussed.

Contrast Media↗
PubMed1978

Systolic flutter of the mitral valve.

Systolic flutter of the mitral valve was observed in 11 cases during the past 3-1/2 years. All patients had mitral regurgitation due to mitral valve prolapse or flail leaflets, and nine of the 11 (82%) had prior or concurrent bacterial endocarditis. Systolic flutter is uncommon in the absence of endocarditis and was observed in only two of 15 patients (13%) with proven chordae tendinae or papillary muscle rupture without historical and pathological evidence of infection involving the mitral valve. Systolic flutter was also not seen in a large number of patients with mitral regurgitation due to other causes. It is postulated that the regurgitation jet of blood across the edge of a structurally abnormal but flexible mitral leaflet is important for the development of flutter.

Aged↗