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Biomedical subjects

J F Breen

Publications and source records attributed to J F Breen.

At least 19 recordsLinked to original sources
PubMed2001

Rapid three-dimensional echocardiography : clinically feasible alternative for precise and accurate measurement of left ventricular volumes.

BACKGROUND: Clinical applicability of conventional ultrasonographic systems using mechanical adapters for 3D echocardiographic imaging has been limited by long acquisition and processing times. We developed a rapid (6-s) acquisition technique that collects apical tomograms using a continuously internally rotating transthoracic transducer. This study was performed to examine the clinical feasibility of rapid-acquisition 3D echocardiography to estimate left ventricular end-diastolic and end-systolic volumes using electron-beam computed tomography as the reference standard. Methods and Results-We collected a series of 6 to 11 apical echocardiographic tomograms, depending on heart rate, in 11 patients. There was good correlation, low variability, and low bias between rapid 3D echocardiography and electron-beam computed tomography for measuring left ventricular end-diastolic volume (r=0.96; standard error of the estimate, 21.34 mL; bias, -4.93 mL) and left ventricular end-systolic volume (r=0.96; standard error of the estimate, 14.78 mL; bias, -6.97 mL). CONCLUSIONS: The rapid-acquisition 3D echocardiography extends the use of a multiplane, internally rotating handheld transducer so that it becomes a precise and clinically feasible tool for assessing left ventricular volumes and function. A rapid-image acquisition time of 6 s would allow repeated image collection during the course of a clinical echocardiographic examination. Additional work must address rapid and automated data processing.

Adult↗
PubMed2001

Contrast echocardiography improves the accuracy and reproducibility of left ventricular remodeling measurements: a prospective, randomly assigned, blinded study.

OBJECTIVES: We sought to assess the impact of contrast injection and harmonic imaging, on the measure by echocardiography of left ventricular (LV) remodeling. BACKGROUND: Left ventricular remodeling is a precursor of LV dysfunction, but the impact of contrast injection and harmonic imaging on the accuracy or reproducibility of echocardiography is unclear. METHODS: We prospectively collected LV images by using simultaneous methods. Then, LV volumes were measured off-line, in blinded manner and in random order. The accuracy of echocardiography was determined in comparison to electron beam computed tomography (EBCT) in 26 patients. The reproducibility of echocardiography was assessed by three blinded observers with different training levels in 32 patients. RESULTS: End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF), as measured by EBCT (195 +/- 55, 58 +/- 24 and 137 +/- 35 ml and 71 +/- 5%, respectively) and echocardiography with harmonic imaging and contrast injection (194 +/- 51, 55 +/- 20 and 140 +/- 35 ml and 72 +/- 4%, respectively), showed no differences (all p > 0.15) and excellent correlations (all r > 0.87). In contrast, echocardiography using harmonic imaging without contrast injection underestimated the EBCT results (all p < 0.01). Reproducibility was superior with rather than without contrast injection for intraobserver and interobserver variabilities (all p < 0.001). Values measured by different observers were different without contrast injection, but were similar with contrast injection (all p > 0.18). Consequently, intrinsic patient differences represented a larger and almost exclusive proportion of global variability with contrast injection for EDV (94 vs. 79%), ESV (93 vs. 82%), SV (87 vs. 53%) and EF (84 vs. 41%), as compared with harmonic imaging without contrast injection (all p < 0.005). CONCLUSIONS: For assessment of LV remodeling, echocardiography with harmonic imaging and contrast injection improved the accuracy and reproducibility, as compared with imaging without contrast injection. With contrast injection, variability was almost exclusively due to intrinsic patient differences. Therefore, when evaluation of LV remodeling is deemed important, assessment after contrast injection should be the preferred echocardiographic approach.

Aged↗
PubMed2001

Imaging of the pericardium.

Computed tomography (CT) and magnetic resonance imaging (MRI) are modalities well suited for imaging of the pericardium and pericardial disease. Both offer excellent resolution with a wide field of view. Both have advantages and disadvantages when compared with each other and with echocardiography. Establishing the diagnosis of constrictive pericarditis is a common indication for CT or MRI of the pericardium. Pericarditis, neoplasms, effusions, and congenital anomalies are additional conditions involving the pericardium that can be diagnosed with CT and MRI.

Heart Neoplasms↗
PubMed2001

High-spatial-resolution contrast-enhanced MR angiography of the renal arteries: a prospective comparison with digital subtraction angiography.

PURPOSE: To evaluate a high-spatial-resolution three-dimensional (3D) contrast material-enhanced magnetic resonance (MR) angiographic technique for detecting proximal and distal renal arterial stenosis. MATERIALS AND METHODS: Twenty-five patients underwent high-spatial-resolution small-field-of-view (FOV) 3D contrast-enhanced MR angiography of the renal arteries, which was followed several minutes later by more standard, large-FOV 3D contrast-enhanced MR angiography that included the distal aorta and iliac arteries. For both acquisitions, MR fluoroscopic triggering and an elliptic centric view order were used. Two readers evaluated the MR angiograms for grade and hemodynamic significance of renal arterial stenosis, diagnostic quality, and presence of artifacts. MR imaging results for each patient were compared with those of digital subtraction angiograms. RESULTS: The high-spatial-resolution small-FOV technique provided high sensitivity (97%) and specificity (92%) for the detection of renal arterial stenosis, including all four distal stenoses encountered. The portrayal of the segmental renal arteries was adequate for diagnosis in 19 (76%) of 25 patients. In 12% of the patients, impaired depiction of the segmental arteries was linked to motion. CONCLUSION: The combined high-spatial-resolution small-FOV and large-FOV MR angiographic examination provides improved spatial resolution in the region of the renal arteries while maintaining coverage of the abdominal aorta and iliac arteries.

Aged↗
PubMed2000

Calcific constrictive pericarditis: is it still with us?

BACKGROUND: The presence of pericardial calcification on a plain radiograph strongly suggests constrictive pericarditis in patients with heart failure. However, calcific constrictive pericarditis is considered rare in the United States since tuberculosis incidence has decreased, and doubt has therefore been raised about the importance of this radiologic finding in modern cardiovascular practice. OBJECTIVE: To determine the clinical and prognostic significance of pericardial calcification on radiography in patients with constrictive pericarditis. DESIGN: Retrospective cohort study. SETTING: Tertiary referral center. PATIENTS: A consecutive series of 135 patients (mean age +/- SD, 56 +/- 16 years) who from 1985 through 1995 had constrictive pericarditis confirmed surgically (n = 133) or by autopsy (n = 2). Patients were divided into two groups: those with pericardial calcification on chest radiography (group I) and those without (group II). MEASUREMENTS: Clinical and diagnostic findings were compared in both groups, and outcome was compared in 132 patients who had pericardiectomy. RESULTS: Pericardial calcification was seen in 36 patients (27%). The cause of constrictive pericardial disease was indeterminate in 67% of patients in group I and in 21% of patients in group II (P < 0.001). Patients in group I had had symptoms for a longer period and were more likely to have pericardial knock, larger atrial size, and atrial arrhythmia. Significantly more perioperative deaths were seen in group I, but incidence of late survival and incidence of noncalcific disease were similar in both groups. CONCLUSIONS: Pericardial calcification is a common finding in patients with constrictive pericarditis. It is often associated with idiopathic disease and other markers of disease chronicity and is an independent predictor of increased perioperative mortality rates.

Adolescent↗
PubMed2000

Localized aortic dissection: unusual features by transesophageal echocardiography.

Transesophageal echocardiography relies on the presence of an undulating intimal flap for the diagnosis of aortic dissection. Furthermore, to distinguish true dissection from echo artifacts, the flap has to be identified in more than one view, and it must have a motion independent of the aortic wall. We describe the transesophageal echocardiography appearance of a localized aortic dissection with atypical features for an intimal flap. Awareness of this unusual echocardiographic appearance of an intimal flap will avoid misdiagnosis of the potentially serious acute aortic dissection.

Aged↗
PubMed2000

Three-dimensional contrast-enhanced MR angiography with real-time fluoroscopic triggering: design specifications and technical reliability in 330 patient studies.

Technical reliability was determined for triggering three-dimensional (3D) contrast material-enhanced magnetic resonance (MR) angiography with MR fluoroscopy. Technical requirements for high reliability were also identified. Reliability was evaluated in 330 consecutive patient studies of the neck, thorax, abdomen, and pelvis. Contrast material arrival was detected fluoroscopically in 325 of the 330 studies (98.5%), and the 3D sequence was successfully triggered in 321 of 330 studies (97.3%). Fluoroscopic triggering of centrically encoded 3D MR angiographic acquisitions is a highly reliable means of obtaining 3D MR angiograms with high spatial resolution.

Abdomen↗
PubMed2000

Calcified left ventricular mass: unusual clinical, echocardiographic, and computed tomographic findings of primary cardiac osteosarcoma.

Primary cardiac osteosarcomas are rare and usually originate in the left atrium. In contrast, osteosarcomas metastatic to the heart most commonly involve the right cardiac chambers. This case report describes an unusual primary cardiac osteosarcoma, initially observed as a slowly growing, densely calcified mass of the left ventricle with subsequent secondary pulmonary metastasis. Although cardiac tumors may be asymptomatic, this patient had recurrent bouts of ventricular tachyarrhythmia. We describe the clinical, echocardiographic, and radiological observations spanning 6 years and the gross and microscopic features at autopsy.

Calcinosis↗
PubMed1999

Use of electron-beam computed tomography in the evaluation of chest pain patients in the emergency department.

STUDY OBJECTIVE: We sought to determine whether electron-beam computed tomography (EBCT) could be used as a triage tool in the emergency department for patients with angina-like chest pain, no known history of coronary disease, normal or indeterminate ECG findings, and normal initial cardiac enzyme concentrations. METHODS: We conducted a prospective observational study of 105 patients admitted between December 1995 and October 1997 to the ED of a large tertiary care hospital with 70,000 annual ED visits. The study group was comprised of women aged 40 to 65 years and men aged 30 to 55 years who presented with angina-like chest pain requiring admission to the hospital or chest pain observation unit. All patients underwent EBCT of the coronary arteries, along with other cardiac testing as deemed necessary by staff physicians. RESULTS: Of the 105 patients, 100 underwent other cardiac testing during hospitalization. Evaluation included treadmill exercise testing in 58, coronary angiography in 25, radionuclide stress testing in 19, and echocardiography in 11. Results of EBCT and cardiac testing were negative for both in 53 patients (53%), positive for both in 14 (14%), positive for tomography and negative for cardiac testing in 32 (32%), and negative for tomography and positive for cardiac testing in only 1 patient. This positive test result, on a treadmill exercise test, was ruled a false positive by an independent staff cardiologist. Two other female patients with normal exercise sestamibi or coronary angiography and EBCT findings also had false-positive treadmill exercise results. The sensitivity of EBCT was 100% (95% confidence interval, 77% to 100%), with a negative predictive value of 100% (95% confidence interval, 94% to 100%). Specificity was 63% (95% confidence interval, 54% to 75%). CONCLUSION: EBCT is a rapid and efficient screening tool for patients admitted to the ED with angina-like chest pain, normal cardiac enzyme concentrations, indeterminate ECG findings, and no history of coronary artery disease. Our study suggests that patients with normal initial cardiac enzyme concentrations, normal or indeterminate ECG findings, and negative results on EBCT may be safely discharged from the ED without further testing or observation. Larger studies are required to confirm this conclusion.

Adult↗
PubMed1999

Coronary calcification by electron beam computed tomography and obstructive coronary artery disease: a model for costs and effectiveness of diagnosis as compared with conventional cardiac testing methods.

OBJECTIVES: The purpose of this study was to determine if electron beam computed tomography (EBCT) has potential as a cost-effective approach to diagnosis of obstructive coronary disease. BACKGROUND: Coronary calcification quantified by EBCT is closely related to the extent of atherosclerosis. METHODS: A model based upon published sensitivities (Se)/specificities (Sp) for diagnosis in an ambulatory patient of obstructive coronary disease (> or =50% stenosis) and population prevalence was tested for angiography alone, or treadmill exercise, stress echocardiography, stress thallium or predetermined EBCT calcium score outpoints, followed by angiography if indicated. RESULTS: Total direct testing costs increased in proportion to disease prevalence whereas cost-effectiveness, direct costs/patient diagnosed correctly with disease, decreased as a function of prevalence. Using an EBCT calcium score of 168 (Se/Sp = 71%/90%) provided for the least costly and most cost-effective noninvasive pathway. Calcium scores of 80 (Se/Sp = 84%/84%) and 37 (Se/Sp = 90%/77%) were also cost-effective when prevalence of disease was < or =70%; but results for a >0 calcium score (Se/Sp = 95%/46%) cutpoint were not superior to conventional methods. Calcium score cutpoints of 37, 80 or 168 provided similar or superior overall negative and positive predictive values to conventional noninvasive testing pathways across all prevalence subgroups. CONCLUSIONS: In ambulatory patients evaluated for obstructive coronary disease, a testing pathway utilizing quantification of coronary calcium by EBCT as an initial noninvasive testing approach minimized direct costs, and maximized cost-effectiveness in population groups with low/ moderate disease prevalence (< or =70%); as expected, direct angiography as the first and only test proved most cost-effective in patients with a high prevalence (>70%) of disease.

Calcinosis↗
PubMed1999

Telemedicine consultations in congenital heart disease: assessment of advanced technical capabilities.

OBJECTIVE: To assess the value of adding remote pointer and dynamic display capabilities to a telemedicine system designed to provide consultative services for patients with congenital heart disease. MATERIAL AND METHODS: Independent observations by the referring physician and the consulting physician provided the data for the assessment. Fifty-four teleconsultations involving 38 patients with 21 different congenital heart diseases were analyzed. The teleconsultations were based on previously obtained cineangiograms that were digitized and then transmitted by combined satellite and terrestrial-based technology. The observations, recorded by each physician at his workstation at the time of each teleconsultation, were summarized and analyzed statistically. RESULTS: In 108 observations, the pointer was believed to be helpful in 72 (67%), and dynamic display was helpful in 96 (89%). CONCLUSION: This study suggests that use of a pointer and dynamic display enhances teleconsultations for patients with congenital heart disease.

Arizona↗
PubMed1997

Electron beam computed tomographic coronary calcium score cutpoints and severity of associated angiographic lumen stenosis.

OBJECTIVES: We sought to determine a range of cutpoints for coronary calcium scores measured by electron beam computed tomography (EBCT) in predicting the likely severity of associated angiographic coronary artery stenoses. BACKGROUND: EBCT can quantify coronary calcium and allow the estimation of atherosclerotic plaque burden, but use of the calcium score to define lumen narrowing is controversial. METHODS: A total of 213 patients (mean [+/- SD] age 50 +/- 9 years) underwent coronary angiography and EBCT. Maximal percent diameter stenosis in any artery was paired with total coronary calcium score. Receiver operating characteristic (ROC) curve analysis was done using definitions of "disease" for maximal stenosis from > or = 20% to 100%, and the corresponding score cutpoints were determined for 90% sensitivity, 90% specificity or "optimal" sensitivity and specificity. RESULTS: ROC curve areas ranged from a mean (+/- SE) of 0.91 +/- 0.02 for > or = 20% stenosis to 0.83 +/- 0.03 for 100% stenosis. Optimal calcium score cutpoints consisted of nonoverlapping values ranging from 15 for > or = 20% stenosis to 327 for 100% stenosis, whereas sensitivities and specificities ranged from 78% to 84%, depending on maximal stenosis severity. Calcium score cutpoints for 90% sensitivity and 90% specificity were also nonoverlapping and ranged from 3 and 27, respectively, for > or = 20% stenosis to 154 and 945, respectively, for 100% stenosis; corresponding specificities and sensitivities ranged from 40% to 78%. CONCLUSIONS: These data define the ranges for EBCT coronary calcium score cutpoints that predict the likely severity of associated maximal angiographic stenosis severity to a high sensitivity, high specificity or optimal sensitivity/specificity. These cutpoints potentially can be used in conjunction with clinical variables to predict the severity of lumen narrowing in patients undergoing assessment for coronary artery disease.

Adult↗
PubMed1997

Pericardial thickness measured with transesophageal echocardiography: feasibility and potential clinical usefulness.

OBJECTIVES: This study assessed the reliability of transesophageal echocardiographic measurements of pericardial thickness and the potential diagnostic usefulness of this technique. BACKGROUND: Transthoracic echocardiography cannot reliably detect thickened pericardium. The superior resolution achieved with transesophageal echocardiography should allow better pericardial definition. METHODS: Pericardial thickness measured at 26 locations in 11 patients with constrictive pericarditis who underwent intraoperative transesophageal echocardiography was compared with pericardial thickness measured with electron beam computed tomography. Intraobserver and interobserver variabilities were determined. Pericardial thickness was then measured in 21 normal subjects. With these values as a guide, two observers reviewed 37 transesophageal echocardiographic studies to determine whether echocardiographic measurement of pericardial thickness could be used to distinguish diseased from normal pericardium. RESULTS: The correlation between echocardiographic and computed tomographic measurements (r > or = 0.95, SE < or = 0.06 mm, p < 0.0001) was excellent. The +/-2 SD limits of agreement were +/-1.0 mm or less for pericardial thickness < 5.5 mm and +/-2.0 mm or less for the entire range of thicknesses. Intraobserver and interobserver agreements were good. Mean normal pericardial thickness was 1.2 +/- 0.8 mm (+/-2 SD) and did not exceed 2.5 mm. Pericardial thickness > or = 3 mm on transesophageal echocardiography was 95% sensitive and 86% specific for the detection of thickened pericardium. CONCLUSIONS: Measurement of pericardial thickness with transesophageal echocardiography is reproducible and should be a valuable adjunct in assessing constrictive pericarditis.

Case-Control Studies↗
PubMed1997

Coarctation of the aorta: collateral flow assessment with phase-contrast MR angiography.

OBJECTIVE: The purpose of this report is to describe a new use of MR imaging in coarctation of the aorta. The specific question addressed was how well collateral blood flow in intercostal arteries, as determined by phase-contrast MR angiography, correlated with findings during surgery or catheterization in patients with coarctation of the aorta. CONCLUSION: Phase-contrast MR angiography is an excellent technique for detecting the presence or absence of collateral blood flow in the intercostal arteries of patients with coarctation of the aorta. Knowing whether collateral blood flow is present in patients with narrowing of the juxtaductal aorta should help assess the clinical hemodynamic significance of the coarctation.

Adult↗
PubMed1997

Determination of ventricular ejection fraction: a comparison of available imaging methods. The Cardiovascular Imaging Working Group.

Knowledge of left ventricular ejection fraction has been shown to provide diagnostic and prognostic information in patients with known or suspected heart disease. In clinical practice, the ejection fraction can be determined by using one of the five currently available imaging techniques: contrast angiography, echocardiography, radionuclide techniques of blood pool and first pass imaging, electron beam computed tomography, and magnetic resonance imaging. In this review, we discuss the clinical application as well as the advantages and disadvantages of each of these methods as it relates to determination of ventricular ejection fraction.

Angiocardiography↗
PubMed1997

Right and left ventricular remodeling after orthotopic single lung transplantation for end-stage emphysema.

BACKGROUND: Orthotopic single lung transplantation (LTX) is now an established treatment modality for patients with end-stage emphysema. LTX has been shown to cause unloading of the right ventricle with improvement in right ventricular (RV) structure and function both immediately and up to weeks after surgery, mostly in patients with severe pulmonary hypertension and decreased RV function. Long-term effects of lung transplantation on both RV and left ventricular (LV) anatomy and function, however, are not well known. METHODS: Seventeen patients undergoing LTX for end-stage emphysema and preserved RV function underwent serial electron beam computed tomography RV and LV function studies before, 3 months after, 1 year after, and 2 years after transplantation. Right-sided heart catheterization was performed before transplantation and at 1 and 2 years follow-up. RESULTS: RV end systolic volume decreased significantly (-15.5%), and RV ejection fraction increased significantly (+16%) in the first 3 months after LTX. This change was paralleled by a decrease in pulmonary pressure and vascular resistance, indicating a permanent RV unloading. This improvement was maintained up to 2 years after LTX. LV end-diastolic volume (+25%), LV stroke volume (+29%), and LV muscle mass (+28%) increased significantly in the first 3 months after LTX. This remodeling was maintained during the 2-year follow-up. CONCLUSIONS: Significant changes in cardiac anatomy and function occur shortly after LTX, most likely as a consequence of adaptation to a new hemodynamic state in patients with well preserved RV function before LTX. Furthermore, these acute changes persist for at least 2 years after LTX.

Adult↗