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Biomedical subjects

A D Waggoner

Publications and source records attributed to A D Waggoner.

At least 19 recordsLinked to original sources
PubMed2005

Cardiac magnetic resonance imaging abnormalities in systemic lupus erythematosus: a preliminary report.

The purpose of this prospective, pilot study was to determine whether differences in myocardial T2 relaxivity can be identified among active systemic lupus erythematosus (SLE) patients with clinically suspected SLE myocarditis, other active SLE patients, inactive SLE patients and age and gender matched controls. Eleven consecutive female patients (six with active SLE and five with inactive SLE), and five age, gender and race matched healthy controls underwent imaging with echocardiography and cardiac magnetic resonance imaging (MRI). Echocardiographic measurements included left ventricular end diastolic (LVEDV) and end systolic volumes (LVESV), and mass (LVM) (all indexed to body mass); ejection fraction and cardiac output. The cardiac MRI measurement was the T2 relaxation time (an index of soft tissue signal, with higher levels suggestive of increased tissue water content). Patients with active SLE had significantly higher LVEDV and LVM than inactive SLE patients and healthy controls, and significantly larger LVESV than healthy controls. Myocardial T2 relaxation times were significantly higher in patients with active SLE compared to those with inactive SLE and to healthy controls, and remained higher even after excluding the two active SLE patients who had clinical myocarditis. The four active SLE patients who underwent repeat cardiac imaging studies after clinical improvement showed normalization of these myocardial abnormalities. The conclusion was that active SLE patients demonstrate abnormalities in myocardial structure manifested by high myocardial T2 relaxation times that normalized after clinical improvement in disease activity. These findings suggest that T2 relaxation values are a sensitive indicator of myocardial disease in patients with SLE and that myocardial T2 relaxation abnormality frequently occur in patients with active SLE, even in the absence of myocardial involvement by clinical criteria.

Adult↗
PubMed2001

Tissue Doppler imaging: a useful echocardiographic method for the cardiac sonographer to assess systolic and diastolic ventricular function.

Tissue Doppler imaging (TDI) has evolved to become a useful noninvasive method that can complement other echocardiographic techniques in the assessment of left ventricular myocardial velocities in a variety of clinical conditions. Color 2-dimensional and color M-mode TDI are used for quantification of systolic myocardial velocities during myocardial ischemia at rest and with pharmacologic stress testing. Spectral pulsed TDI can provide measurements of regional systolic and diastolic myocardial velocities, and it is particularly useful in the identification of abnormalities of left ventricular diastolic relaxation. This review summarizes the clinical applications of TDI to promote understanding of its utility in the evaluation of left ventricular myocardial function.

Blood Flow Velocity↗
PubMed2001

Licensure of the cardiac sonographer: an overview of issues and activities.

The impact of echocardiography on the continuum of cardiovascular health care is well established. Ongoing concerns regarding costs, accessibility, quality, and appropriateness of services rendered by practitioners of echocardiography have prompted various legislative proposals and regulatory policies from government, medical professional groups, and health plans. Specifically, there continues to be a drive to enact law for licensure of sonographers. These activities require continuing advocacy for the profession with active leadership. As part of its mission statement, the American Society of Echocardiography (ASE) states, "ASE strives to be a leader in public policy in order to create a favorable environment for excellence in the practice of echocardiography." As such, the ASE is committed to an increase in their interaction with legislators, payers, and policy makers. This article describes the historical perspective of state, federal, and provincial sonographer licensure issues to provide an understanding of the political perspectives.

Allied Health Personnel↗
PubMed2000

Congestive heart failure and the role of two-dimensional Doppler echocardiography: a primer for cardiac sonographers.

Congestive heart failure (CHF) has been an increasing cause of hospitalization, particularly among the elderly population, although the clinical presentation may vary in the individual patient. Two-dimensional and pulsed Doppler echocardiography can be valuable diagnostic methods for the assessment of afflicted patients and can have an impact on patient outcome. The unique advantage of echocardiographic techniques is their ability to characterize left ventricular systolic performance and diastolic filling abnormalities that are commonly present in patients with CHF. This review provides current information the cardiac sonographer can recognize in the assessment of patients with CHF.

Echocardiography, Doppler↗
PubMed1999

Potential utility of left heart contrast agents in diagnosis of myocardial rupture by 2-dimensional echocardiography.

This case illustrates the use of intravenous injections of a contrast agent during 2-dimensional echocardiography in a patient with myocardial rupture after myocardial infarction. Intravenous injections of echocardiographic contrast agents may have potential use in the identification of intrapericardial hemorrhage after myocardial infarction caused by myocardial rupture or development of ventricular pseudoaneurysm.

Aged↗
PubMed1999

The profession of cardiac sonography and the status of professionalization of cardiac sonographers.

The role of the cardiac sonographer has evolved in the profession of cardiac ultrasonography to a level requiring rigorous education, training, and high standards. Although we want to consider ourselves professionals, further efforts are necessary to meet the various criteria conferring such a status. It is essential cardiac sonographers realize these necessary steps to achieve recognition as professionals.

Allied Health Personnel↗
PubMed1995

Right ventricular dysfunction in low output syndrome after cardiac operations: assessment by transesophageal echocardiography.

BACKGROUND: Low output syndrome after cardiac operations is associated with high morbidity and mortality rates. The contribution of right ventricular dysfunction to this syndrome has not been fully characterized. The purpose of this study was to evaluate the utility of transesophageal echocardiography to identify the frequency and the in-hospital mortality from right ventricular dysfunction in patients with this syndrome. METHODS: Seventy-five consecutive patients undergoing transesophageal echocardiography for low output syndrome early after cardiac operations were evaluated. The findings from transesophageal echocardiography were correlated with the type of surgical procedure, cross-clamp time, right heart hemodynamics, and coronary angiography. RESULTS: Right ventricular systolic dysfunction occurred in 36 patients (42%); in 17 patients it was isolated and in 19 patients it occurred in combination with left ventricular dysfunction. Postoperative right ventricular dysfunction was not uniformly associated with important right coronary artery disease or with prolonged ischemic time during cardiopulmonary bypass. Hemodynamic data were not useful to distinguish the group with postoperative right ventricular dysfunction. Patients with right ventricular dysfunction had a high (44%) in-hospital mortality rate. CONCLUSIONS: Right ventricular dysfunction occurs frequently in patients with low output syndrome after cardiac operations and is associated with a high in-hospital mortality rate. Better understanding of the mechanisms causing postoperative right ventricular dysfunction may provide insight for preventing this complication.

Adult↗
PubMed1994

Quantitative ultrasonic tissue characterization of myocardium in cyanotic adults with an unrepaired congenital heart defect.

Adults with nonrestrictive ventricular septal defects have chronic hypoxemia that may lead to alterations in myocardial structure and function. Ultrasonic integrated backscatter provides quantitative assessment of myocardial acoustic properties that are altered by myocardial ischemia, fibrosis, and edema. Sixteen patients (age 31 +/- 10 years) with a nonrestrictive ventricular septal defect were studied using 2-dimensional and M-mode echocardiography with integrated backscatter imaging to determine the cyclic variation of integrated backscatter in the right ventricular free wall, ventricular septum, and left ventricular posterior wall. Cyclic variation of integrated backscatter in the right ventricular free wall and interventricular septum in patients was significantly less than that in control subjects (4.1 +/- 0.8 vs 4.9 +/- 1.0 decibels [dB], p = 0.02, and 3.8 +/- 1.2 vs 4.8 +/- 1.1 dB, p = 0.004, respectively). There was no difference between mean cyclic variation of integrated backscatter in the left ventricular posterior wall in patients and that in control subjects (4.7 +/- 1.3 vs 4.8 +/- 1.1 dB, p = NS, respectively). However, values < 4.0 dB were noted in 38% of patients compared with 15% of control subjects. Biventricular systolic function was normal in all but 1 patient. There was no correlation between backscatter and either wall thickness or percent wall thickening from the 3 regions. Histologic analysis of myocardial tissue in 3 patients revealed interstitial and replacement fibrosis. Adults with nonrestrictive ventricular septal defects exhibit alterations in tissue-acoustic properties detectable by integrated backscatter imaging despite preserved systolic function and wall thickening.

Adult↗
PubMed1994

Restoration of atrial function after the maze procedure for patients with atrial fibrillation. Assessment by Doppler echocardiography.

BACKGROUND: The purpose of the present study was to evaluate the effects of the maze procedure on atrial function in patients operated on for atrial fibrillation. The maze procedure is a new surgical intervention that is designed to restore sinus rhythm and active mechanical atrial contraction as a definitive treatment for patients with atrial fibrillation. METHODS AND RESULTS: Doppler echocardiographic analysis of mitral and tricuspid inflow as well as pulmonary venous flow velocity was carried out in 46 patients 8 +/- 7 months after the maze procedure, and results were compared with those obtained from 27 age-matched control subjects. To evaluate atrial contraction, we determined the presence of atrial contribution to ventricular filling at the mitral and tricuspid valve levels and measured the percent atrial filling fractions of the left and right atria. To evaluate atrial compliance, we measured the systolic and the systolic-to-diastolic flow velocity ratios of the pulmonary venous inflow. Results were compared with similar measurements obtained from control subjects. Restoration of active atrial contraction was detected in 40 of the 46 patients (87%); right atrial contraction was noted in 38 patients (83%), and left atrial contraction was noted in 28 patients (61%). In patients with active atrial contraction, the percent atrial filling fraction of the right atrium was comparable to that of control subjects (32 +/- 7% versus 33 +/- 8%, P = NS), whereas that of the left atrium was smaller (20 +/- 5% versus 36 +/- 7%, P < .005). In addition, compared with control subjects, pulmonary venous flow in maze patients exhibited a reduced systolic component (17 +/- 4 versus 53 +/- 16 cm/s, P < .001) and decreased systolic-to-diastolic flow velocity ratio (0.3 +/- 0.01 versus 1.1 +/- 0.3, P < .001) and velocity integral ratio (0.3 +/- 0.01 versus 1.3 +/- 0.4, P < .001), all suggesting decreased left atrial filling. CONCLUSIONS: The maze procedure restores active right atrial contraction and improves left atrial contraction in most patients. Obtained measurements suggest decreased left atrial compliance and reduced left atrial contribution to ventricular filling compared with control subjects. Despite the reduced indexes, qualitative restoration of function in either atria should translate in improved atrioventricular synchrony and reduction in thromboembolic events in patients with chronic or paroxysmal atrial fibrillation.

Atrial Fibrillation↗
PubMed1994

Ultrasonic tissue characterization: integrated backscatter imaging for detecting myocardial structural properties and on-line quantitation of cardiac function.

Quantitative myocardial tissue characterization is being developed as an adjunct to conventional echocardiography to delineate the physical state of myocardium under diverse pathophysiological states. Real-time quantitative integrated backscatter imaging has made possible clinical investigations carried out in the United States, Europe, and Japan in patients with ischemic heart disease, hypertrophic cardiomyopathy, and cardiac allograft rejection, among others. A modification of the imaging processing used for characterization of tissue facilitates automatic detection of endocardial blood interfaces and on-line quantification of ventricular size and function, which has been recently introduced in clinical practice. Further progress and developments in quantitative ultrasonic imaging will place in perspective the clinical use of tissue characterization based on myocardial backscatter.

Animals↗
PubMed1993

Right and left ventricular area and function determined by two-dimensional echocardiography in adults with the Eisenmenger syndrome from a variety of congenital anomalies.

The Eisenmenger syndrome has been associated with right ventricular (RV) enlargement and systolic dysfunction. However, little attention has been directed toward potentially characteristic changes in left ventricular (LV) dimensions or function. Therefore, 2-dimensional echocardiography (short-axis-papillary muscle level) was performed in 24 adults (mean age 33 +/- 7 years) with Eisenmenger syndrome to evaluate RV and LV size and function. A significant correlation was found between RV and LV end-diastolic areas (r = 0.96; regression slope 1.06), and fractional area change (r = 0.88; regression slope 1.03) in patients with a nonrestrictive ventricular septal defect (VSD) (n = 15). In contrast, in patients with Eisenmenger syndrome but no VSD (n = 9), RV and LV end-diastolic areas (r = 0.68; regression slope 0.10), and fractional area change (r = 0.08; regression slope -0.09) were discordant. RV function was preserved in most patients with a VSD, and mean RV fractional area change was significantly greater than in those without a VSD (0.50 +/- 0.13 vs 0.18 +/- 0.08; p < 0.001). No significant difference was apparent in these 2 groups (patients with and without a VSD) with respect to age, pulmonary artery systolic pressure, partial arterial oxygen pressure or hematocrit. Thus, the results indicate a relation between biventricular chamber dimensions and systolic function that is dependent on the nature and locus of the primary intracardiac defect responsible for the Eisenmenger syndrome.

Adult↗
PubMed1993

Dobutamine stress echocardiography predicts surgical outcome in patients with an aortic aneurysm and peripheral vascular disease.

OBJECTIVES: This study was conducted to assess the utility of dobutamine stress echocardiography for determining the presence of significant coronary artery disease and for predicting surgical outcome and long-term prognosis in patients scheduled to undergo peripheral vascular or aortic aneurysm surgery. BACKGROUND: Assessment of coronary artery disease in patients scheduled to undergo peripheral vascular surgery can avoid perioperative complications. METHODS: Dobutamine stress echocardiography was performed in 98 consecutive patients scheduled to undergo aortic or peripheral vascular surgery. Intravenous dobutamine was infused in a graded fashion, with two-dimensional digital echocardiographic monitoring of ventricular function and segmental wall motion. Group 1 (n = 70) consisted of patients who exhibited a normal response to dobutamine infusion (negative dobutamine study); group 2 (n = 23) comprised those patients with an abnormal response to dobutamine, characterized by the development of new or worsening wall motion abnormalities at rest, indicating the presence of myocardial ischemia (positive dobutamine study). Five patients with an inconclusive dobutamine study (because of inadequate heart rate) were excluded from analysis. RESULTS: No major adverse effects occurred with testing in any patient. Sixty-eight of 70 patients with a negative study had peripheral vascular or aortic surgery performed without perioperative cardiac events (2 patients refused surgery). Nineteen of 23 patients with a positive study underwent coronary angiography and all had > 50% lumen narrowing in one or more major coronary artery distributions; 13 underwent coronary artery bypass grafting or angioplasty before peripheral vascular or aortic surgery and all had an uneventful perioperative period. Four of the 10 patients from group 2 who did not undergo coronary revascularization had a perioperative cardiac event (myocardial infarction in 2, an ischemic episode requiring urgent coronary bypass grafting in 1 and congestive heart failure in 1). CONCLUSIONS: Positive and negative dobutamine study results are significant predictors of the presence or absence of perioperative events (20% vs. 0%, p = 0.003). A positive test warrants coronary angiography and further medical or surgical intervention, or both, but a negative test indicates a low likelihood of perioperative cardiac complications of aortic or peripheral vascular surgery. During the long-term follow-up period in this study (group 1 mean, 24 months; group 2 mean, 15 months), two patients (3%) from group 1 and three (15%) from group 2 developed cardiac complications (p = 0.038). Thus, dobutamine stress echocardiography is safe and can predict surgical outcome in patients undergoing aortic aneurysm repair or surgery for occlusive disease of the peripheral arteries. In addition, a negative test result is a strong predictor of decreased perioperative and long-term cardiac morbidity and mortality.

Aged↗
PubMed1993

Echocardiographic characterization of the improvement in right ventricular function in patients with severe pulmonary hypertension after single-lung transplantation.

OBJECTIVES: This study was designed to characterize immediate, early and long-term changes in right ventricular structure and function, as defined by two-dimensional and Doppler echocardiography, after single-lung transplantation in patients with severe pulmonary hypertension. BACKGROUND: Single-lung transplantation has recently been shown to dramatically improve hemodynamics in patients with primary pulmonary hypertension who had unsuccessful medical therapy. METHODS: Fourteen patients with severe pulmonary hypertension who underwent single-lung transplantation were studied with transthoracic and transesophageal two-dimensional and Doppler echocardiography. Right ventricular dimensions were measured in the apical four-chamber view. Right ventricular ejection and acceleration times and peak velocity of tricuspid regurgitation were measured by Doppler study. Results of right heart catheterization were available early (< 3 months) after transplantation in 10 of 13 patients and late after transplantation (6 months to 2 years) in 11 patients. RESULTS: In the early posttransplantation studies, right ventricular dimensions decreased and fractional area change and ejection fraction increased in all patients, but right ventricular wall thickness did not change significantly. Tricuspid regurgitation lessened markedly in all patients. Long-term decreases in right ventricular dimension and improvement in systolic function were sustained. Right ventricular wall thickness significantly decreased compared with the early postoperative value (0.76 +/- 0.1 cm compared with 0.63 +/- 0.14 cm, p < 0.02). CONCLUSIONS: Two-dimensional echocardiography demonstrates sustained improvement in right ventricular function after single-lung transplantation for severe pulmonary hypertension despite severe preoperative dysfunction.

Cardiac Catheterization↗
PubMed1993

Comparison of color flow imaging and peripheral venous saline contrast during transesophageal echocardiography to evaluate right-to-left shunt at the atrial level.

Intravenous injections of agitated saline (contrast) are used to identify right-to-left atrial shunt during transesophageal echocardiography (TEE). Color flow imaging (CFI) with TEE can be used to detect left-to-right atrial shunt but its application to detect right-to-left shunt is not known. We performed CFI and contrast during TEE in 72 patients for detection of right-to-left shunt. Frame-by-frame review of CFI demonstrated discrete laminar jets of the left side of the atrial septum at the lower or upper margin of the fossa ovalis (FO) in 41 (57%) of 72; only 22 had positive contrast. Timing of shunts was late diastolic or early systolic and not related to pulmonary venous inflow. The length of the FO at end-systole was greater in those with positive CFI compared to negative CFI (13.5 +/- 5 vs 11 +/- 4 mm, P = 0.02). CFI was positive for right-to-left shunt in ten of 14 with atrial septal aneurysms. Contrast was positive for right-to-left shunt in 29 (40%) of 72; all but six had positive CFI. The degree of left atrial opacification was minimal in 19 and moderate to severe in ten. FO size was greater in positive versus negative contrast (14 +/- 4 vs 11 +/- 5 mm, P = 0.02). Contrast was positive for shunt in ten of 14 with septal aneurysms. Thus, right-to-left atrial shunt more often occurs with increased FO size and septal aneurysms.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Two-dimensional Doppler color flow imaging in adults with L-transposition of the great arteries.

Abnormalities of the left atrioventricular (AV) (tricuspid) valve and pulmonic stenosis are part of the spectrum of manifestations in patients with corrected transposition of the great arteries (L-TGA). However, the utility of Doppler color flow imaging combined with two-dimensional echocardiography in L-TGA has not been established. Thus, we evaluated 14 adults (mean age 33 +/- 8 {SD} years) with L-TGA. Two-dimensional echocardiography demonstrated Ebstein's anomaly in five patients. Color flow imaging detected left AV valve regurgitation in 13 (moderate to severe in six); the other patient had a prosthetic valve. Right AV valve regurgitation was detected in two (mild in both). Aortic regurgitation was present in five (moderate in three). Pulmonic regurgitation was present in nine (moderate to severe in three). Pulmonic stenosis was detected in three (subvalvular in two, valvular in one) and two patients had pulmonary atresia. One patient had a bicuspid aortic valve with mild stenosis. Mean right ventricular ejection fraction (apical, area-length) was 44%; only 1 of 9 patients had a value greater than 55%. Thus, two-dimensional Doppler echocardiography with color flow imaging detects a high incidence of systemic AV valvular regurgitation and reduced right (systemic) ventricular systolic function in adults with L-TGA.

Adult↗