bluuebunny/crossref_metadata_2025 huggingface dataset:
Bicycle Stress Echocardiography
Authors: RYAN THOMAS
Published: August 2007

Bicycle stress echocardiography involves the recording and interpretation of two‐dimensional echocardiographic information before, during, and after bicycle exercise. The exercise test can be performed in the supine or upright posture. While there are important physiological differences between these two positions, they appear to provide similar diagnostic information on the presence or absence of coronary artery disease. A major advantage of bicycle stress echocardiography compared to treadmill exercise is the ability to image at peak exercise, rather than relying solely on pre‐ and postexercise imaging. This contributes to the greater sensitivity of the test for the detection of ischemia. The recent application of digital processing techniques may also improve sensitivity by permitting side‐by‐side comparison of rest and stress images. In summary, bicycle stress echocardiography is a useful tool in the management of patients with known or suspected coronary artery disease. It is a versatile and accurate technique, which competes favorably with other imaging modalities and provides information on regional and global left ventricular function.
Dipyridamole Echocardiography
Authors: CASTELLO RAMON , LABOVITZ ARTHUR J.
Published: August 2007

Intravenous dipyridamole is a potent coronary vasodilator that has been extensively investigated over the past several years in the noninvasive assessment of patients with suspected coronary artery disease when exercise cannot be performed or is suboptimal. As an alternative to exercise studies, dipyridamole has been used in combination with different cardiac imaging techniques such as echocardiography, thallium scintigraphy, and radionuclide ventriculography. Extensive experience has been obtained with dipyridamole thallium‐201 imaging for coronary artery disease screening, risk stratification, and prognosis after an acute coronary event. However, experience with the use of dipyridamole in combination with two‐dimensional echocardiography has been limited. Dipyridamole increases coronary blood flow in nondiseased coronary vessels relative to coronary vessels with significant luminal narrowings. These provide the basis for detecting regional differences in flow by using different cardiac imaging techniques. Two‐dimensional echocardiography would show regional wall‐motion abnormalities in response to those regional differences in coronary blood flow. In this article, the most commonly used protocols, safety, and practicability of dipyridamole echocardiography are reviewed. As an alternative to exercise, dipyridamole echocardiography shares all the indications of a standard exercise test. Clinical applications of dipyridamole echocardiography include coronary artery disease screening, suspected coronary artery spasm, postmyocardial infarction risk stratification, evaluation of percutaneous transluminal coronary angioplasty results, and prognosis following an acute coronary event. Compared to conventional (ECG) exercise testing, dipyridamole echocardiography appears to be equally sensitive but more specific. Compared to atrial pacing, dipyridamole provokes ischemia at a lower rate pressure product and results in a greater ST segment depression suggesting that dipyridamole induces more profound myocardial ischemia than atrial pacing. Dipyridamole thallium and exercise thallium have shown to be equally sensitive and specific in the assessment of coronary artery disease. High dose dipyridamole echocardiography appeared to be equally sensitive and more specific. Experimental studies have demonstrated that dobutamine appears to be a more powerful pharmacological agent in inducing wall‐motion abnormalities. Dipyridamole echocardiography as compared to stress echocardiography offers the advantage of obtaining better quality postintervention images. With regard to sensitivity and specificity for coronary artery disease diagnosis, both techniques appear to render similar results. Although further studies are needed, the available data indicates that cardiac ultrasound imaging prior to and following the intravenous administration of dipyridamole may be an attractive alternative to thallium perfusion imaging in the clinical setting, particularly when radionuclide capabilities are not present.
Echocardiographic and Doppler Findings in Primary Sarcoma of the Pulmonary Artery
Authors: PINAMONTI BRUNO , SINAGRA GIANFRANCO , SLAVICH GIANNI , CALUCCI FULVIO , MANZINI VINCENZO DE PANGHER , BUSSANI ROSSANA , SILVESTRI FURIO
Published: August 2007

Primary sarcoma of the pulmonary artery is a rare heart tumor. In the reported case, the clinical findings were nonspecific, and were characterized by progressive dyspnea, fever, and a systolic murmur in the pulmonary area. Echocardiographic examination showed an echogenic mass partially obstructing the pulmonary artery trunk, dilation of the right cardiac chambers, and a pressure overload pattern. Doppler and color Doppler demonstrated a high‐velocity systolic flow jet in the pulmonary artery due to obstruction of the vessel by the tumor, as well as severe high‐velocity tricuspid regurgitation. The patient died suddenly soon thereafter. The autopsy confirmed almost total occlusion of the pulmonary artery by a neoplastic mass. Histopathological diagnosis was primary vascular leiomyosarcoma of the pulmonary artery. In addition, a large tumor embolus had occluded the right pulmonary artery. Doppler echocardiography proved useful in noninvasively recognizing the sarcoma of the pulmonary artery, and explaining the clinical picture and hemodynamic derangements produced by this tumor. This could, in other patients, allow an early diagnosis and timely surgical intervention.
Catecholamine Stress Echocardiography
Authors: SAWADA STEPHEN G. , SEGAR DOUGLAS S. , RYAN THOMAS , DOHAN ALI M. , WILLIAMS ROXANNE , FEIGENBAUM HARVEY
Published: August 2007

Two‐dimensional echocardiographic monitoring during catecholamine infusion has shown promise as a safe and accurate method for detection of coronary artery disease. The clinical application of catecholamine stress echocardiography has been facilitated by the development of digital image processing techniques. The sensitivity of this method of stress testing has been improved by drug infusion protocols that are designed to maximize myocardial stress. Recent investigations have demonstrated the value ofdobutamine stress echocardiography for detection of multivessel disease following myocardial infarction and for assessment of cardiac risk before noncardiac surgery. Evaluation of changes in wall motion and thickening that occur during low dose dobutamine infusion may enable detection of viable myocardium after thrombolytic treatment of acute myocardial infarction. Compared to alternative noninvasive diagnostic methods, catecholamine stress echocardiography permits continuous acquisition of high‐quality information on regional and global systolic function. This and other advantages have prompted the search for broader applications of this technique.
Dipyridamole‐Echocardiography: Clinical Usefulness Following Interventions
Authors: PICANO E. , BOLOGNESE L. , PIRELLI S. , LATTANZI F. , SARASSO G. , PICCININO C. , FALETRA F. , MASSA D. , MARINI C. , DISTANTE A.
Published: August 2007

Dipyridamole‐echocardiography test response can be expressed not only in a black or white (positive vs negative) code but also, in positive tests, by a gray scale integrating the severity and extent of the dyssynergy as well as the ischemia‐free stress time. The recognition of the dyssynergy is important to establish the diagnosis; however, the evaluation of the degree of the induced ischemia, stratified according to spatiotemporal coordinates, is even more important because it accurately predicts the coronary anatomical and functional situation, as well as the prognosis of the individual patient. Furthermore, the “shades of gray” in a positive response have proved useful in assessing the beneficial effects of several interventions: coronary angioplasty; coronary artery bypass surgery; thrombolysis; and medical antianginal therapy. Due to its excellent reproducibility, dipyridamole‐echocardiography can play a pivotal role for simple, safe, fast, accurate, and objective assessment of therapeutic interventions, either mechanical or pharmacological, based upon the presence, timing, severity, and extent of dipyridamole‐induced dyssynergy.
Exercise Evaluation of Prosthetic Heart Valves by Doppler Echocardiography: Comparison with Catheterization Studies
Authors: DRESSLER FREDERICK A. , LABOVITZ ARTHUR J.
Published: August 2007

Although valve replacement remains the cornerstone of treatment for critical heart valve dysfunction, problems including thromboembolism, infection, and primary failure of the prosthesis remain. Resting studies of valve hemodynamics are sometimes insufficient to reveal valve dysfunction. Early studies using cardiac catheterization focused on changes in prosthetic function seen with various types of exercise or drug‐induced stress. These studies suffered from an inability to adequately stress catheterized patients and were cumbersome to the patient and the investigator. With the introduction of Doppler echocardiography, however, studies could be performed after significant exercise with low risk and increased ease. Using echocardiography, reports of exercise‐induced changes in aortic and mitral valve hemodynamics have appeared. Over 600 patients have been studied using Doppler echocardiography. In the aortic position, all prostheses studied have a mild peak instantaneous gradient (18–26 mmHg) at rest, which increases with exercise (35–63 mmHg). No significant differences between the four models of mechanical prostheses studied are found. The gradients achieved with exercise do not appear to be related to the heart rate achieved or duration of exercise. Smaller prostheses are associated with larger gradients; however, the correlation was not strong. All mitral valve prostheses studied are also mildly stenotic at rest (range of mean gradients 2.3–7.1 mmHg) and become moderately stenotic with exercise (range 5.1–16.5). Although the lowest gradients are seen with St. Jude Medical and Medtronic Hall prostheses, their gradients are not significantly less than with other valves. Exercise duration and heart rate attained are not correlated to gradient, and valve size is not related to gradient except in the case of the larger St. Jude Medical valves. Other factors predictive of low levels of exercise tolerance are age >50 and predominant mitral regurgitation before replacement. In summary, exercise Doppler echocardiography offers a noninvasive technique to evaluate prosthetic heart valves. It is reproducible, safe, and less cumbersome than cardiac catheterization. A range of normal exercise hemodynamics has been established for aortic and mitral prostheses. Using these parameters, the diagnosis of early prosthetic dysfunction can be made.
Assessment of Aortic Coarctation and Collateral Circulation By Biplane Transesophageal Echocardiography
Authors: RYAN KEVIN , SANYAL RAJAT S. , PINHEIRO LUIZ , NANDA NAVIN C.
Published: August 2007

Our experience in using biplane transesophageal echocardiography in the assessment of coarctation of the aorta is described.
Left and Right Coronary Artery Aneurysm Associated with Right Coronary Artery Occluding Thrombus: Demonstration by Transesophageal Echocardiography
Authors: HSIUNG MING‐CHON , KU CHANG‐SHENG , LIN CHEN‐CHEE , DING YU‐AN , WANG DANG‐JIEN , SHIEH SHYH‐MING , LIN KO‐CHOW
Published: August 2007

This case provides a demonstration of the improved utility of transesophageal echocardiography, as compared to angiography and conventional echocardiography, in the setting of Kawasaki disease. Transesophageal echocardiography was able to demonstrate aneurysm and thrombolytic occlusion of the right coronary artery (RCA), whereas transthoracic echocardiography could not detect the occlusion and angiography missed the RCA findings altogether.
Pulmonary Artery Catheter‐Associated Thrombosis
Authors: WOLFE MARK , REIMOLD SHARON C. , COUPER GREGORY , LEE RICHARD T.
Published: August 2007

Transesophageal echocardiography has become increasingly important in the assessment of critically ill patients. We report a 39‐year‐old patient who was incidentally noted to have a large right intraatrial thrombus associated with an indwelling pulmonary artery catheter identified by transesophageal echocardiography. This led to eventual catheter removal by open venotomy. Careful examination of intravascular devices during transesophageal echocardiography may lead to early diagnosis of catheter‐associated thrombosis and thus alter management appropriately.
Cardiovascular Ultrasound: Expanding Frontiers in Vascular Disease
Authors: MARTIN RANDOLPH P. , APPELBE ALAN , SIGANOS JANET
Published: August 2007

Advances in cardiovascular ultrasound have included development of instrumentation providing outstanding images, as well as color spectral Doppler hemodynamic information. The increasing utilization of cardiovascular ultrasound has led to its increasing diagnostic application and accuracy in the evaluation of the patient with known or suspected cerebrovascular and peripheral vascular disease. The sensitivity of duplex ultrasound to detect carotid disease varies from 87% to 94% with a specificity of 88% to 93%. The accuracy of duplex examination for detection of peripheral venous disease, when compared to contrast venography, is high. A sensitivity of nearly 93% with a specificity of 98% has been noted. Cardiovascular ultrasound is a noninvasive technology with no known biological hazard that can be applied to the broad spectrum of patients including those who are critically ill. It is a relatively low‐cost procedure when compared to other diagnostic procedures and can be performed on a serial basis. Since it provides anatomical and functional hemodynamic information, it is rapidly becoming the procedure of choice not only for diagnosis, but also for management.
Echocardiographic Diagnosis of a Partially Thrombosed Right Coronary Artery Aneurysm in a Patient with Polycystic Disease
Authors: HAUSMANN DIRK , DÜRST URS N. , FREI ULRICH , DANIEL WERNER G.
Published: August 2007

This report describes a patient with polycystic disease of the kidneys and the liver and an aneurysm of the proximal right coronary artery. Transthoracic and transesophageal echocardiographic imaging showed a 5 times 5 cm oval‐shaped, spherical tumor in the atrioventricular corner. The tumor was partially filled with homogenous echostructures. Coronary angiography showed aneurysmatic configuration of the right coronary artery, but no region demonstrating a mass of similar size and shape as seen by echocardiography. The finding of a partially thrombosed coronary artery aneurysm was subsequently confirmed by surgery.
Transesophageal Echocardiographic Diagnosis of Aortopulmonary Fistula
Authors: CHEN CHUNG‐HUO , NANDA NAVIN C. , FAN POHOEY , SANYAL RAJATSUBHRA , HSIUNG MING C. , ALLAM ABDULGADER R.
Published: August 2007

Our case illustrates the value of transesophageal echocardiography in the assessment of patients suspected or diagnosed to have prosthetic aortic valve endocarditis. In addition to making a correct diagnosis of the exact site and nature of the aortopulmonary fistula, the technique also correctly demonstrated the location and extent of all the abscess cavities. The two perforations in the anterior mitral leaflet as well as the disruption of the aortic prosthesis with paraprosthetic leak were also correctly characterized.
Mediastinal Liposarcoma Causing Left Ventricular Inflow Tract Obstruction: Diagnosis by Transesophageal Echocardiography
Authors: CHOW WING‐HING , CHOW TSUN‐CHEUNG , CHEUNG HENRY , CHEUNG DAVID , CHEUNG KING‐LOONG
Published: August 2007

A patient with mediastinal liposarcoma causing left ventricular inflow tract obstruction is described. The location of the tumor and its pressure effect were accurately diagnosed by transesophageal echocardiography.
Problems and Pitfalls in the Echocardiographic Assessment of Pericardial Effusion
Authors: D'CRUZ IVAN A. , CONSTANTINE ARTHUR
Published: August 2007

The echocardiographic diagnosis of pericardial effusions is usually based on visualization of a sonolucent circumcardiac space of varying width. However, potential fallacies in interpretation can arise if sonolucent spaces adjacent to the heart (pleural effusions, ascites, pericardial cysts) are mistaken for pericardial effusions. Loculated pericardial effusions, especially if unusual in location or configuration, can cause diagnostic difficulty on occasion. The differential diagnosis of various “solid” echoes within a pericardial effusion is of clinical relevance, yet not widely discussed. Inflammatory tissue, neoplastic involvement, pus, caseous material, and extravasated blood all have characteristic echocardiographic morphologies. All of the various reported echocardiographic signs of tamponade do not have the same significance, so that caution is necessary not to over‐ or under‐read tamponade. Chamber collapse can be absent in real tamponade in specific situations. On the other hand, “regional” tamponade can occur if loculated pericardial effusions are sufficiently large and high tension; echocardiographic appearances are “atypical” but diagnostically valuable if correctly interpreted. These and certain other unusual variants oftamponade deserve to be better known among echocardiographers not only because of their intrinsic interest, but also to avoid potential pitfalls in the echocardiographic assessment of patients with suspected disease.
Use of Echocardiography in Detecting Cardiac Sources of Embolus
Authors: GUTTERMAN DAVID D. , AYRES RICHARD W.
Published: August 2007

Up to 20% of all ischemic strokes are felt to be the result of emboli from the heart. High resolution transthoracic (TTE) and transesophageal (TEE) echocardiography have been the principal diagnostic tools for detecting associated cardiac abnormalities and for guiding medical and surgical approaches to these patients. In addition to identifying the precise location and morphological characteristics of intracardiac masses, echocardiography has improved our ability to predict embolic potential of these masses. Specific cardiac lesions that are predisposed to stroke and are readily identifiable by echocardiography include: cardiac thrombi, valvular vegetations, cardiac tumors, aortic atheroma, atrial septal aneurysm, and regional left ventricular wall abnormalities. Careful interrogation of patients with cerebrovascular accidents has identified a potential cardiac source of embolus in approximately 30%. This is largely due to the advent of TEE, which has provided much better assessment of posterior cardiac chambers including left atrium and left atrial appendage. Use of TEE in identifying a cardiac source of embolus is indicated in patients with stroke who are young, have no apparent cerebrovascular disease, or have recurrent embolic events. Echocardiography is an essential diagnostic tool in evaluating patients with a suspected cardiac source of embolus. TTE and TEE provide invaluable information regarding the majority of cardiac sources of embolus.
Transthoracic Echocardiography versus Transesophageal Echocardiography in Detecting Cardiac Sources of Embolism
Authors: PEARSON ANTHONY C.
Published: August 2007

Although the yield of potential cardiac sources of embolism by echocardiography in patients with stroke and arterial embolism has been low, with the advent of transesophageal echocardiography, a renewed enthusiasm for echocardiography in these patients has developed. This article reviews the six major studies comparing transthoracic to transesophageal echocardiography in the search for potential cardiac sources of embolism. The overall yield of transesophageal echocardiography in these studies for potential cardiac sources of embolism is 43% compared to 14% by transthoracic echocardiography in a total of 367 patients. In patients without clinical cardiac disease, the yield is lower but still substantially higher by transesophageal echocardiography (24% compared to 7% by transthoracic echocardiography). For left atrial thrombus, left atrial spontaneous contrast, patent foreman ovale, and atrial septal aneurysm (ASA), transesophageal echocardiography is clearly superior than transthoracic echocardiography. Data on the detection of mitral valve prolapse and left ventricular thrombus are conflicting and neither method is clearly superior. In addition, transesophageal echocardiography identifies certain abnormalities including debris in the aorta and prosthetic strands that transthoracic echocardiography is incapable of identifying. Although transthoracic echocardiography should continue to be the initial screening modality for stroke patients, transesophageal echocardiography should be performed when surface findings are negative or equivocal in patients with likely cardioembolic stroke.
Abnormalities of the Interatrial Septum as a Potential Cardiac Source of Embolism:
Authors: KICHURA GEORGE M. , CASTELLO RAMON
Published: August 2007

Stroke is a common and often devastating medical condition for the inflicted patient and his/her family. Certain abnormalities of the interatrial septum have recently been considered as potential causes for cerebral ischemic events. These abnormalities include atrial septal aneurysm (ASA) and patent foramen ovale (PFO). ASA is described as a bulging of the interatrial septum involving the region of the fossa ovalis. The prevalence of ASA is higher in patients undergoing transesophageal echocardiography (TEE) due to unexplained cerebral ischemia (15%) when compared to that of patients who had TEE performed for other reasons (4%). This apparently strong association between ASA and cerebral embolism has led to the consideration of ASA as a potential source of embolism. TEE appears to be more sensitive than transthoracic echocardiography (20% vs 6%) in detecting PFO. As with ASA, the prevalence of PFO is higher in those patients referred for unexplained cerebral ischemia than in those undergoing transesophageal studies for other reasons. Although a strong association between ASA, PFO, and stroke has been shown, the prognostic implications of these abnormalities are unclear. Therefore, longitudinal, prospective, and large scale studies are needed to evaluate the prognosis and clinical significance of these abnormalities.
Exercise Echocardiography in Combined Mild Mitral Valve Stenosis and Regurgitation
Authors: TISCHLER MARC D. , NIGGEL JOELYN
Published: August 2007

Dynamic mitral regurgitation (MR) is typically associated with either severe systolic left ventricular dysfunction or episodes of acute myocardial ischemia. We report three patients with mild combined mitral stenosis and regurgitation and normal global left ventricular systolic function who presented with severe exertional dyspnea. Upright bicycle exercise echocardiography revealed development of severe dynamic MR in all three cases with Doppler evidence of severe pulmonary hypertension. There was no echocardiographic or electrocardiographic evidence of ischemia. Exercise echocardiography is an established tool for assessing dynamic changes in transvalvar pressure gradients. These results suggest that exercise echocardiography may also be useful for evaluating changes in severity of MR and for the assessment of dynamic changes in pulmonary artery systolic pressures.
Intraoperative Transesophageal Echocardiography Using High Resolution Imaging in Infants and Children with Congenital Heart Disease
Authors: MUHIUDEEN ISOBEL , SILVERMAN NORMAN
Published: August 2007

A transesophageal probe recently has been developed for use in pediatric patients, which incorporates 48 rather than 26 elements, and permits continuous‐wave Doppler, and pulsed and color Doppler flow modalities. This probe potentially offers significantly enhanced image quality. To evaluate its capabilities, we tested the probe intraoperatively in 53 infants and children undergoing surgical repair of congenital heart disease, and found that clear echocardiographic images with good detail were provided, including the ability to image coronary arteries in patients weighing as little as 2.7 kg. Imaging detail transesophageally is commensurate with the performance of this system from a transthoracic route. This probe also has the capacity for accurate estimates of high velocity jets using continuous‐wave Doppler, which is a relatively new development. (ECHOCARDIOGRAPHY, Volume 10, November 1993)
Real‐Time, Automated Echocardiographic Measures of Ventricular Area and Area Change:
Authors: MARTIN GERARD R. , SEIBEL NITA L. , MAJD MASSOUD
Published: August 2007

Echocardiography now permits tracking of the blood‐endocardial border and automatic measurement of ventricular area throughout the cardiac cycle. To determine the accuracy of this technique, we compared echocardiographic measurements of area with similar measurements made by radionuclide technique in 19 children, ages 4–24 years (mean 13 years). The blood‐endocardial border was tracked from the apical two‐chamber view and radionuclide measurements were made from the left anterior oblique view. We measured echocardiographic end‐diastolic area, end‐systolic area, and fractional area change from the average of five cardiac cycles. The radionuclide area measurements were made from a gated blood pool study incorporating 700–1200 cardiac cycles. Results were compared by bias analysis. The mean differences (± 1 SJD.) between left ventricular area measurements were: end‐diastole 1.13 ± 2.3 cm2, end‐systole –0.90 ± 1.33 cm2, and fractional area change 7.4 ± 9.3 (%). Differences between the measurements were within the limit of agreement (mean ±2 S.D.) in 55 of 57 measurements. The area measurements were not free from bias; the mean differences of area measurements were significantly different from zero for end‐diastolic area (P ≤ 0.05), end‐systolic area (P ≤ 0.01), and fractional area change (P ≤ 0.002). Echocardiography tended to underestimate end‐diastolic area and fractional area change and it tended to overestimate end‐systolic area. Realtime tracking of the blood‐endocardial border is possible and allows accurate measurement of ventricular area.

echocardiography, radionuclide, tissue characterization
Physiological Assessment of Coronary Artery Disease and Myocardial Viability in Ischemic Syndromes Using Adenosine Echocardiography
Authors: CASE R. ALEX , BUCKMIRE ROBERT , McLAUGHLIN DAVID P. , KELLER MARK
Published: August 2007

We hypothesized that it would be feasible and safe to use adenosine echocardiography to assess the physiological significance of coronary stenoses, detect ischemic myocardium, and assess myocardial viability in a high risk group of patients with coronary artery disease (CAD). Therefore, in 40 patients with either unstable angina, non‐Q myocardial infarction, or myocardial infarction treated with thrombolytic therapy, we performed adenosine echocardiography (140 μglkg per min for 5 mins with a 16 segment model for analysis) and compared the findings with quantitative planar thallium‐201 scintigraphy, and (in 26 patients) coronary angiography. The technique was safe, and there were no serious complications. Adenosine resulted in a significant increase in heart rate and decrease in blood pressure. The sensitivity of adenosine echocardiography and thallium scintigraphy were 96% and 88%, respectively, for detecting > 75% stenosis. The change in echo score from baseline during adenosine infusion was significantly higher with more severe coronary disease (single vessel right coronary artery [RCA] or left circumflex [LCX] disease = 0.125± 0.15, proximal left anterior descending coronary artery [LAD] disease = 023 ±0.15, RCA and LCX disease=0.30 ± 0.14, LAD and RCA and/or LCX disease = 0.62 ± 0.13). Likewise, the echo score during adenosine infusion was significantly higher in patients with high risk thallium scans (low risk = 1.29 ± 0.26, medium risk = 1.74 ± 022, and high risk= 2.21 ± 0.37). In 13 patients receiving thrombolytic therapy, adenosine echocardiography identified 12 with viable myocardium as defined by quantitative thallium criteria. Furthermore, the wall‐motion response of the viable segment was indicative of the degree of stenosis of the artery subtending the segment. Regional function deteriorated in patients with high grade (95 ± 2%) stenoses and improved in those with nonflow limiting stenoses (66 ± 25%, P = 0.03). Therefore, we conclude that adenosine echocardiography can detect significant coronary stenoses, has a high degree of concordance with thallium in detecting cardiac perfusion abnormalities, and can assess myocardial viability following thrombolytic therapy.

adenosine echocardiography, thallium scintigraphy, unstable angina, thrombolytic therapy, viability
Analysis of Right Ventricular Kinesis by Means of Transesophageal Echocardiography:
Authors: KOZÁKOVÁ MICHAELA , PALOMBO CARLO , BENANTI CESARE , L'ABBATE ANTONIO , DISTANTE ALESSANDRO
Published: August 2007

The evaluation of right ventricular (RV) kinesis by two‐dimensional echocardiography represents a difficult task. Transthoracic echocardiography can visualize the RV in several projections, but the image quality and the variability of imaging views usually do not allow quantitative analysis. We investigated the potential of transesophageal echocardiography (TEE) for evaluating RV global function and regional kinesis, in 32 controls and in 16 patients with inferior myocardial infarction (MI) and asynergy involving the inferior wall of both ventricles. Good‐quality images of at least one horizontal section of the RV were obtained in 73% of subjects by conventional, 90o sector and in 100% of subjects by wide‐angle, “panoramic” sector. Images of the RV in short‐axis view at medium level were acquired and evaluated in 93% of cases, but at basal and apical levels only in 67% and 39%, respectively. The low percentage of successful detection and evaluation of the RV at apical level can be explained by prominent motion and trabeculation of the apex. Global systolic area changes (SAC) in controls attained similar values at apical and medium levels (60% and 59%, respectively), but were significantly lower (48%, P < 0.05) at basal level. In patients with previous inferior MI and inferoposterior asynergy, global SAC were significantly (P < 0.01) lower at medium and basal levels (32% and 27%, respectively) compared with controls. Regional kinesis of RV was assessed as segmental SAC in 12 different segments, by fixed and float system of center of cavity. In controls, the fixed system underestimated kinesis of inferior and septal segments and overestimated kinesis of anterolateral segments, due to leftward translation and inferior rotation of the RV during systole. Float system showed almost concentric kinesis of the RV, with segmental SAC between 53% and 66%. In patients with RV asynergy, the fixed system confirmed the “eyeball” analysis, while float system tended to mask the asynergy and showed more uniform kinesis, with diffuse decrement in SAC throughout all segments. Further evaluation, also by biplane and omniplane probes, may help overcome the limitations of the present method for a comprehensive analysis of R V kinesis. TEE, however, already allows improving the echocardiographic assessment of RV kinesis and appears to be a promising tool, and potentially a reference technique, for investigation of R V kinesis during stress.

right ventricle, transesophageal echocardiography, ventricular function, quantitative analysis
Errors in Pressure Gradient Measurement in Prosthetic Aortic Valves Due To Pressure Recovery: Type, Size, and Flow Rate Effects In Vitro
Authors: STEWART SANDY F.C. , ARABIA FRANCISCO A. , NAST EDWARD P. , TALBOT THOMAS L. , PROSCHAN MICHAEL , CLARK RICHARD E.
Published: August 2007

We assessed errors in valvular pressure gradients due to pressure recovery, the variation in aortic pressure with distance from the valve, to explain errors in catheter measurements and simultaneous continuous‐wave Doppler/catheter studies. Ten types and three sizes of valves were tested in vitro. Aortic pressure was measured by catheter between 1 and 6 cm from the valve. Pressure recovery was quantified as the slope of the gradient with distance from the annulus. Valve type, size, and flow rate effects were determined by analysis of variance. Relationships between Doppler and maximal catheter gradients were also analyzed statistically. The slope of pressure recovery was significantly higher in smaller valves (P< 0.01), in bioprosthetic rather than mechanical valves (P < 0.001), and at higher flows (P < 0.0001). Doppler I catheter slopes were dependent on valve type and size, with more overestimation by Doppler in mechanical (P < 0.01) and larger valves (P < 0.01). Errors due to catheter positioning are more likely wherever effects of pressure recovery are higher: in bioprosthetic valves, smaller valves, and at higher flow rates. Pressure recovery can explain overestimation by Doppler only if localized gradients closer than 1 cm from the valve exist. Clinicians should be aware of these effects of pressure recovery when making major diagnostic and therapeutic decisions.
Transesophageal Echocardiographic Features of Unieuspid Aortic Valve
Authors: OSMAN KHIDIR , NANDA NAVIN C. , KIM KEE‐SIK , ROYCHOUDHURY DEBASISH , FINCH ANA D.
Published: August 2007

The usefulness of transesophageal echocardiography in the diagnosis of congenital unieuspid aortic valve is described.
The Paradoxical Pulse in Tamponade: Mechanisms and Echocardiography Correlates
Authors: HOIT BRIAN D. , SHAW DAVID
Published: August 2007

Pulsus paradoxus is an exaggerated fall in systolic blood pressure with inspiration (usually greater than 10 mm). Understanding the accuracy of pulsus paradoxus for a diagnosis of cardiac tamponade requires a consideration of the mechanisms underlying its genesis, and a knowledge of its presence in other conditions and its variable absence in cardiac tamponade with associated disease states. Echocardiography (M‐mode, 2‐D, and Doppler) has aided considerably our understanding of pulsus paradoxus. Inspiratory increases in right heart filling and output are widely accepted as necessary for pulsus paradoxus to occur; inspiration causes increases in right ventricular dimensions and pulmonic and tricuspid velocities, and decreases in left ventricular (LV) dimensions and aortic and mitral velocities and LV diastolic compliance. Doppler studies of pulmonary venous inflow confirm that an inspiratory fall in left atrial filling is necessary for pulsus paradoxus. Pulsus paradoxus is complex and multifactorial in origin; it may be absent in cardiac tamponade when certain conditions (e.g., LV dysfunction) coexist and may accompany disease states other than cardiac tamponade (e.g., obstructive airway disease). Thus, the significance of pulsus paradoxus (and its Doppler echo correlates) must be considered in the clinical context.
Estimation of Severity of Mitral Regurgitation by Digital Image Processing of Doppler Spectral Recordings
Authors: TAK TAHIR , MATHEWS SAJEN J. , GOEL SANJIV , CHANDRARATNA P.A.N.
Published: August 2007

In order to test the hypothesis that the intensity of the regurgitant signal (RS) is indicative of severity of mitral regurgitation (MR), we digitized five well‐defined MR envelopes in 19 patients and calculated the mean pixel intensity (MPI) of the MR envelope and that of the diastolic inflow signal (DIF) using an offline computer system. The mean age of the patients was 49 years (range 19–78 years). The intensity of the RS was expressed as a ratio of the MPI of DIF (RSI DIF). This ratio was compared to the severity of MR determined by left ventricular angiography (LV angio). The ratio of the RSI DIF correlated well with the angiographic severity of MR (r = 0.9). A ratio of < 0.6 identified patients with moderate to severe MR and a ratio of < 0.6 correlated with mild MR (grade I and II) by LV angio. Our data indicate that MR severity assessed by measurement of the intensity of the RS correlates well with the angiographic determination of MR.
Visualization of Pattern Flow in Abdominal Arteries by Transgastric Echocardiography After Aortic Dissection Repair
Authors: IUS PAOLO , SALVADOR LORIS , ROCCO FRANCESCO , ROS ANTONIA DA , BELLI PAOLA , ROSI PAOLO , VALFRE‘ CARLO
Published: August 2007

The persistence of false lumen after surgical repair of aortic dissection is frequent. This event has a negative impact on the prognosis and is secondary to the persistence of unrepaired entry sites and of dissected major aortic branches. We describe three cases in which visualization of a dissected celiac trunk with an anomalous flow pattern was possible with transesoghageal echocardiography. Two of these cases died in the early postoperative period and the echo findings were confirmed at necropsy. We suggest that visualization of anomalous pattern flow in the celiac trunk is of prognostic relevance because it plays a major role in mantaining the false lumen persistence and, therefore, should be part of the routine examination after surgical repair of aortic dissection.
The Role of Echocardiography in Assessing the Morphological Response of Left Ventricular Thrombus to Anticoagulation
Authors: LEE KAMTHORN S. , LEVER HARRY M.
Published: August 2007

We present a patient with idiopathic dilated cardiomyopathy and a large left ventricular apical thrombus in which serial echocardiography over a 1‐month period documented progressive enlargement of this mural thrombus. This case illustrates the dramatic progression of left ventricular thrombus size despite aggressive anticoagulation. In addition, the critical role of echocardiography in the diagnosis and follow‐up of patients with left ventricular thrombus is emphasized.
Transthoracic Real‐Time Three‐Dimensional Echocardiography Using a Fan‐Like Scanning Approach For Data Acquisition
Authors: DELABAYS ALAIN , PANDIAN NATESA G. , CAO QI‐LING , SUGENG LISSA , MARX GERALD , LUDOMIRSKI ACHI , SCHWARTZ STEVEN L.
Published: August 2007

Three‐dimensional echocardiography is an emerging clinical method to assess cardiovascular disorders. The feasibility of using a linear mode scanning (parallel slicing) for transthoracic data acquisition has been demonstrated. In this study, we evaluated the feasibility of real‐time transthoracic three‐dimensional imaging of the heart using a fan‐like scanning mode of echocardiographic data acquisition. We used a computer‐driven motor to sequentially angulate transthoracic transducers over a fan‐like arc up to 90°. With careful ECG and respiratory gating, we acquired basic two‐dimensional data set via parasternal and subcostal windows and performed dynamic three‐dimensional reconstructions. The problems encountered included the need to repeat data acquisition sequences because of transducer movement or inappropriate gain and grayscale settings. From 15 scanning sequences in four patients, we were able to use ten sets of data. These yielded good quality three‐dimensional studies projecting normal valves, a stenotic mitral valve, and an atrial septal defect, in a number of novel views. The valves could be visualized from above and fioni below as well as in other orientations, and the detailed anatomy appraised. Spatial relationships of the atrial septal defect with inferior and superior vena cava, coronary sinus, or tricuspid annulus could be uniquely displayed through views from the right side of the heart. This technique provided adequate new imaging planes not available from two‐dimensional echocardiography. This experience demonstrates for the first time that transthoracic three‐dimensional echocardiography using a fan‐like scanning mode of data acquisition is feasible, and that it provides adequate visualization ofintra‐cardiac structures in unique projections. This article presents the first clinical experience with this approach. Further developments of this technique could propel three‐dimensional echocardiography in day‐to‐day clinical practice.
Increased Fetal Activity and Heart Rate During and Immediately After Pulsed Doppler Echocardiography
Authors: SAEIAN KIA , WEINTRAUB ROBERT , HAGEN‐ANSERT SANDRA , SAHN CHRISTINE , SHIOTA TAKAHIRO , KENNY ANTOINETTE , SAHN DAVID J.
Published: August 2007

Introduction: Previous reports have suggested that the use of continuous‐wave Doppler for nonimaging heart rate monitoring or in utero Doppler imaging increased fetal activity. In this study, 11 fetuses (EGA 20–28 weeks) underwent a cardiac 2‐D ultrasound and pulsed Doppler examination (since pulsed Doppler is more often used for fetal cardiac diagnosis) with 2‐D and Doppler performed in a randomized order and with 10‐minute ultrasound observation periods with as little transducer movement as possible before, during, and after 2‐D only, and Doppler evaluation. Methods: All studies were performed with informed consent at the lowest available Doppler power < 90 mW/cm2 spatial peak temporal average. Fetal heart rate, the number of fetal gross movements / min, and the percent time occupied by fetal movements were evaluated by two blinded observers from video taped records. Patients had been referred to rule out fetal heart disorders but all echoes showed normal cardiac anatomy. Results: Fetal heart rate after pulsed Doppler study was statistically higher by analysis of variance (mean 127 beats/min) than in the pre‐Doppler evaluation period (mean 120) and was highest during the Doppler exam period (mean 136; P < 0.05) in 10 of 11 fetuses. The percent time of fetal movements was highest during the Doppler exam period and in 9 of 11 fetuses movement increased. The raw number of gross movements / min, however, was highest after the Doppler. No such changes occurred during or after 2‐D alone. Conclusion: Whether associated with slightly higher energy output, minimal thermal changes, or audible switching or electronic output sounds transmitted from the instrumentation through the uterus, fetal heart rate and activity increased in our study both during and after pulsed Doppler examination.
Right Atrial and Ventricular Infarction
Authors: GOMEZ‐VILLALOBOS MA. DE JESUS , VARGAS‐BARRON JESUS , ROMERO‐CARDENAS ANGEL , RIJLAARSDAM MARIA , KEIRNS CANDACE , LUPI‐HERRERA EULO , GONZALEZ‐ESPINO JESUS
Published: August 2007

In order to compare the results of transesophageal echocardiography (TEE) in diagnosis of right atrial (RA) and right ventricular (RV) infarction with those of transthoracic echocardiography (TTE), 11 patients admitted to the coronary care unit with the diagnosis of posteroinferior left ventricular (LV) acute myocardial infarction (MI) and electrocardiographic suspicion of extension to RV were studied. In two of the 11 patients, RA infarction was identified on the basis of akinesis of the RA free wall, dilatation of the atrial cavity, spontaneous echo contrast, mural thrombosis, and poor atrial contribution to RV filling. In all 11 patients, RV infarction was determined by akinesis of one or more segmental regions, dilatation of the cavity in four patients, and tricuspid regurgitation in seven. Only six cases of RV infarction were diagnosed with TTE. The findings indicate that TEE provides additional information to TTE for determining RA and RV infarction during the early stages of MI.
Future Directions in Intravascular Ultrasound
Authors: LANCÉE C.T. , BOM N. , ROELANDT J.
Published: August 2007

Intravascular ultrasound imaging requires both a small transducer assembly and catheter delivery system with optimal flexibil‐ ity and steerability. At this moment, multiele‐ ment electronic arrays provide an optimal catheter delivery system but the transducer assembly is both complicated and expensive while the image quality remains rather fair. Most intravascular ultrasound systems use mechanically rotated ultrasound beam generated by a single element. These systems provide good image quality but the need of a drive shaft restricts both the flexibility and steer ability of the catheter delivery system (Table I). In addition, the drive shaft behaves like spring and due to the curved trajectory of the catheter tube in the vascular system, a complicated frictional interaction will occur. The shaft will show a tendency to wind and unwind during one revolution, yielding a certain unpredictability of the angular position of the scanning head relative to that of the proximal system (Fig. 1).1
Three Dimensional Reconstruction of Transesophageal Echocardiographic Longitudinal Images
Authors: LI ZHI‐AN , WANG XIN‐FANG , NANDA NAVIN C. , LU PING , OFILI ELIZABETH , HU GANG , FAN POHOEY , ZHENG LI‐HUI , KIM KEE‐SIK , DENG YOU‐BIN , YANG YA
Published: August 2007

Using longitudinal transesophageal echocardiography and the concept of three‐dimensional transthoracic echocardiography, we performed three‐dimensional reconstruction of transesophageal images of various clinico‐pathologic cases, including atrial septal defect, mitral stenosis, mitral valve prolapse, and pulmonary stenosis. The hardware equipment and image processing flow chart of three‐dimensional reconstruction of transesophageal echocardiographic images are described in this manuscript. Our present study indicates that three‐dimensional reconstruction of transesophageal echocardiographic images could display multiregional three‐dimensional structure of the heart and great vessels, including superior vena cava, ascending aorta, right ventricular outflow tract, pulmonary artery, and left heart, with clear, visual and stereoscopic imaging. The regional structures could be displayed at different levels of stereo‐anatomic‐sections and at different orientations of rotating stereo images, which could provide accurate three‐dimensional anatomical information for cardiac stereo‐morphological study and definition of spatial location and extent of cardiac abnormalities.
Diagnosis of Fistulas of the Mitral‐Aortic Intervalvular Fibrosa
Authors: KROLICK MERRILL A. , NOVITZKY DIMITRI , FONTANET HECTOR L.
Published: August 2007

A 57‐year‐old white male status post St. Jude aortic prosthesis, who 10 years later presented with congestive heart failure was found to have a fistula between the left ventricular outflow tract and left atrium at the mitral‐aortic intervalvular fibrosa with no evidence of endocarditis or trauma.
Routine Echocardiographic Views Miss Significant Pleural Effusions
Authors: URMAN MARK K. , POLLICK CHARLES
Published: August 2007

Objectives: To determine the benefit of adding chest scanning to the routine echocardiographic examination to diagnose pleural effusions. Background: Pleural effusions are common in several cardiac disorders, yet routine echocardiography is insensitive in delineating pleural fluid. Methods: Bilateral chest scanning was performed in addition to the routine echo examination in 100 consecutive inpatients referred for echocardiography with recent chest X rays (CXRs). Detection and quantification of pleural effusion by sonographic chest scanning was compared blindly with CXRs. Identification of pleural fluid was analyzed for correlation with clinical diagnosis of congestive heart failure (CHF) and elevated pulmonary artery pressures if found by echo‐Doppler examination. Results: Agreement on presence or absence of pleural effusion occurred in 88 of 100 patients—in 5 patients bilateral chest scanning detected pleural effusion with negative CXRs; in 7 patients CXRs suggested pleural effusion with negative bilateral chest scanning (all 7 patients had minor blunting of the costophrenic angle). Routine echo views only detected 22 of 51 patients (43%) with pleural effusion detected by bilateral chest scanning. In 45 patients with CHF, 29 (64%) had pleural effusion by bilateral chest scanning (25 bilateral, 1 left, 3 right) vs 12 (27%) by routine echo (only left pleural effusion seen). Ejection fraction and estimated pulmonary artery pressure did not differ between CHF patients with and without pleural effusion. Conclusions: Routine echocardiographic views underestimate the presence of pleural effusion in patients referred for study. Bilateral chest scanning is equal to CXRs for pleural effusion detection and provides clinically useful information which may be of particular benefit to patients with CHF.