Biomedical subjects
Publications and source records attributed to N C Nanda.
This case report presents the unusual characteristics of a neuroendocrine thymic carcinoma that probably has metastasized to the left side of the interatrial septum from a primary thymic site.
Coronary artery imaging is routinely obtained invasively at cardiac catheterization through coronary angiography. This remains the gold standard, but with advances in ultrasound technology, electron beam computed tomography, and magnetic resonance imaging, newer noninvasive methodologies are achieving greater success at imaging the coronary anatomy. This review is meant to highlight the important accomplishments from transesophageal echocardiographic (TEE) investigations that have studied the coronary arteries. The specific technique for optimally imaging the coronaries with high frequency transducers, color and conventional Doppler, in addition to contrast-enhanced methods, will be analyzed. Importantly, this article serves as a reminder to echocardiographers and cardiologists that excellent, clinically relevant information of the coronary arteries can be obtained routinely during TEE. This technique is part of the trend noted by the other authors in this special edition; that is, echocardiography is becoming the gold standard of the new millennium for many diagnostic areas, even coronary angiography.
We report a patient with traumatic aortic valve injury in whom a large defect in the noncoronary cusp of the aortic valve was clearly visualized by multiplane TEE and confirmed at surgery.
In this case report we present two-dimensional (2-D) and three-dimensional (3-D) transesophageal echocardiographic (TEE) findings of a patient with lipomatous atrial septal hypertrophy and a patient with Hodgkin's lymphoma with atrial septal involvement. The echocardiographic characteristics that differentiate these two lesions are discussed.
We describe a patient with a left main coronary artery fistula with an opening at the superior vena cava-right atrial junction in whom three-dimensional transesophageal echocardiography permitted more accurate assessment of the shape and size of the communication site than two-dimensional transesophageal echocardiography.
Three-dimensional echocardiography is being used with increasing frequency to evaluate cardiac function and structure. We present two cases of prosthetic aortic valve endocarditis where three-dimensional transesophageal echocardiography correlated with the intraoperative surgical findings of prosthetic dehiscence and communication with an abscess cavity. When compared with two-dimensional transesophageal echocardiography, three-dimensional echocardiography was more accurate in defining the exact site of dehiscence and communication with an abscess cavity. The echocardiographic images were oriented as a clockface watch to conform to the surgeon's visualization of the aortic root as viewed from the right side of the patient.
We present a patient in whom the exact location of a right atrial lipoma identified with two- and three-dimensional transesophageal echocardiography (2-D and 3-D TEE) was correlated with the surgical findings. By orienting the 3-D TEE images to conform to the view of the surgeon from the right side of the patient and referencing the site of attachment of the tumor to the surrounding structures, this lipoma was correctly localized to a 7 o'clock position in the right atrium.
We present a patient in whom we successfully reconstructed a long segment of the proximal left vertebral artery in three dimensions using color Doppler transesophageal echocardiography (TEE). Three-dimensional (3-D) color Doppler TEE may complement two-dimensional (2-D) TEE by its ability to view cross sections of the left vertebral artery at any desired level from the 3-D data stored in the computer.
We present a patient in whom power pulse inversion imaging clearly demonstrated a subendocardial myocardial perfusion defect during contrast vasodilator stress using adenosine. The defect was best appreciated with M-mode postprocessing of power pulse inversion imaging data.
We present a technique for transpharyngeal imaging of the bilateral carotid arteries completed towards the end of a transesophageal echocardiogram. To our knowledge, this is the first report that demonstrates the bifurcation of the right common carotid artery into the right internal and external carotid arteries with a transesophageal echocardiographic probe.
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OBJECTIVES: TEE is performed in many patients with ischemic stroke, and it is possible to examine the proximal coronaries by TEE in these patients. Our purpose was to (1) determine the accuracy of transesophageal echocardiography (TEE) in the diagnosis of proximal coronary stenosis in patients with ischemic stroke and (2) show that TEE detection of proximal coronary stenosis changed management in a substantial number of patients. METHODS: Thirty-two patients with ischemic stroke undergoing TEE, in whom the proximal coronaries were examined and who had angiographic results available, were studied. RESULTS: Proximal coronaries were visualized as follows: left main (LM) in 31 (97%), left anterior descending (LAD) in 32 (100%), left circumflex (LCx) in 30 (94%) and right coronary artery (RCA) in 21 (66%). The sensitivity and specificity of TEE in diagnosing significant coronary stenosis in visualized vessels were as follows: LM 100% and 100%, LAD 100% and 95%, LCx 100% and 96%, and RCA 100% and 100%, respectively. When visualized and nonvisualized segments were considered, TEE detected significant stenosis as follows: 4 of 5 in the LM (80%), 13 of 13 in the LAD (100%), 2 of 3 in the LCx (66%), and 2 of 8 in the RCA (25%). Of the 32 patients, TEE results changed management in 17 patients (53%). Angiographic findings resulted in 10 of the 17 patients (59%) undergoing revascularization. CONCLUSIONS: TEE was very accurate in diagnosing significant coexisting coronary artery disease in patients with ischemic stroke. TEE diagnosis of these lesions prompted coronary angiography and subsequent revascularization in a substantial number of patients.
Heart failure is the most common cause of cardiovascular hospitalization in older adults in the United States. This disease is common, disabling, and commonly fatal, especially in the elderly population. Hypertension and coronary artery disease are the leading causes of heart failure. A precise diagnosis of the cardiac abnormality is paramount for adequate treatment, and echocardiography offers the most comprehensive, noninvasive evaluation. With an organized approach using two-dimensional and Doppler echocardiography, the systolic and diastolic left ventricular performance can be determined; the cardiac output, pulmonary artery, and ventricular filling pressures can be estimated; and surgically correctable valve disease can be identified. The response and success of treatment also may be monitored by the judicious use of echocardiography.
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In this report, we present an adult patient with dwarfism who had severe aortic stenosis with markedly thickened fibrotic valve leaflets without calcification. These findings were well demonstrated by both two- and three-dimensional transesophageal echocardiography and confirmed at surgery and by pathological examination.
BACKGROUND: Preoperative recognition of the presence of bicuspid aortic valve can be important in the planning of procedures. Multiplane transesophageal echocardiography may allow more accurate detection of valvular morphology than does biplane transesophageal echocardiography. METHODS AND RESULTS: The studies of 710 patients who subsequently underwent valvular or aortic surgery were reviewed in a blinded fashion. The inclusion criteria were adequate short-axis view and operative note confirmation of aortic valve morphology. Six hundred eight patients were submitted to further analysis. Four hundred three patients had aortic stenosis as the primary diagnosis. Three hundred sixty patients had biplane examinations and 248 had multiplane examinations. The sensitivity and specificity of the multiplane technique in assessing aortic valve morphology (bicuspid vs tricuspid valve) was 87% and 91%, respectively. The sensitivity and specificity of the biplane technique was 66% and 56%, respectively. Whether valves were calcified or not did not result in major changes in sensitivity and specificity for either technique. CONCLUSIONS: Multiplane transesophageal echocardiography provides a more accurate assessment of preoperative aortic valve morphology than does the biplane approach in the majority of patients.
BACKGROUND: Harmonic power Doppler imaging (H-PDI) has been introduced into the field of contrast echocardiography as a contrast-specific imaging modality. However, there has been considerable skepticism as to whether H-PDI would be quantifiable, because it depends on the destruction of microbubbles and has more complex signal processing than gray scale imaging. The aim of the present study was to evaluate the relationship between the concentration of microbubbles and the resulting H-PDI signals even under conditions where bubble destruction is most likely. Furthermore, we evaluated whether microbubbles of Levovist freely pass the microcirculation, which is a prerequisite for the assessment of myocardial blood flow. METHODS AND RESULTS: A strong positive correlation was found between the H-PDI signals and the amount of microbubbles up to the onset of acoustic shadowing (r = 0. 968, P<0.001). Time-intensity curves for H-PDI of air-filled microbubbles were compared with time-concentration curves of indocyanine green (ICG) in both a flow phantom and a working heart setup. The mean transit times (MTTs) through the myocardium of both agents were compared after a bolus injection into the left coronary artery. A close correlation was observed between 1/MTT and flow in both setups (r>0.98, P<0.0001). However, at high flow rates, the MTTs of the microbubbles were slightly, albeit not significantly, faster than those of indocyanine green. CONCLUSIONS: We conclude that microbubbles fulfill the prerequisites of free flowing tracers through the myocardium. Furthermore, H-PDI technology allows a reliable assessment of time-concentration curves of air-filled microbubbles up to the onset of acoustic shadowing.
We describe the usefulness of transesophageal three-dimensional echocardiography in the evaluation of anomalously arising coronary arteries in four adult patients recently studied by us.