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Biomedical subjects

T M Bashore

Publications and source records attributed to T M Bashore.

At least 55 records · Page 3Linked to original sources
PubMed1996

Negative predictive value of the Duke criteria for infective endocarditis.

With use of new Duke criteria, 405 episodes of suspected endocarditis were previously classified as "definite," "possible," or "rejected" endocarditis. To determine the negative predictive value of the Duke clinical criteria for the classification of suspected endocarditis, chart review and follow-up were performed for the 52 episodes in which the diagnosis of endocarditis was rejected. Three of 52 episodes were reclassified to possible endocarditis; 49 episodes in 48 patients met the criteria for rejected endocarditis. Of these 49 episodes, 31 (63%) had a firm alternate diagnosis other than endocarditis, 17 (35%) had resolution of the clinical syndrome leading to the suspicion of endocarditis with < or = 4 days of antibiotics, and 1 patient had no evidence of endocarditis at surgery. Echocardiograms recorded in 3 patients with rejected endocarditis had evidence of oscillating valvular masses, and blood cultures were positive in 13 episodes; none of these patients had evidence of endocarditis at follow-up. Follow-up or outcome information was available in all 49 episodes. Excluding the 5 in-hospital deaths, mean duration (+/- SD) of follow-up was 39.9 +/- 28.8 months (range 0.5 to 108.0); in living patients, mean time to final follow-up was 56.2 +/- 25.2 months (range 25.0 to 108.0). One patient had possible infective endocarditis at autopsy. No patient in our series whose diagnosis of endocarditis had been rejected had proven endocarditis. Therefore, the negative predictive value of the Duke clinical criteria for endocarditis is at least 92%.

Adult↗
PubMed1996

Esophageal varices in association with unilateral pulmonary vein atresia.

A 27-yr-old woman with recurrent episodes of hemoptysis (and hematemesis due to esophageal varices) was found to have unilateral pulmonary vein atresia. Reversed flow in the left pulmonary artery, a finding highly suggestive of this rare congenital anomaly, was demonstrated during cardiac catheterization. The definitive diagnosis was afforded by pulmonary wedge angiography, which not only demonstrated the atretic leftsided pulmonary veins, but also revealed a serpiginous system of systemic collateral veins to be the cause of her esophageal varices. Pneumonectomy of the nonfunctioning hypoplastic lung, the most successful approach to this disorder, may be complicated by severe bleeding of the numerous systemic arterial collateral vessels transected during surgical mobilization of the affected lung. Percutaneously delivered vascular occlusion coils were used in this case to occlude the large systemic to pulmonary artery collateral arteries immediately prior to pneumonectomy. Intra- and perioperative bleeding was minimal, and the patient has done well without further episodes of hemoptysis or hematemesis. Percutaneous occlusion of systemic to pulmonary collaterals may prove useful as a preoperative step for other congenital heart disease patients requiring lung or heart/lung transplantation.

Adult↗
PubMed1996

Late conduit occlusion after modified Fontan procedure with classic Glenn shunt.

A number of patients with complex congenital heart disease who were initially palliated with a classic Glenn shunt subsequently underwent modified Fontan procedures. This report discusses the operative management of complete occlusion of right atrial-to-right ventricular conduits in patients with patent classic Glenn shunts. The literature is reviewed regarding similar patients, and alternative treatment strategies are discussed.

Adult↗
PubMed1996

Total pulmonary artery occlusion immediately after lung transplantation: successful revascularization with intravascular stents.

Occlusion of the pulmonary artery anastomosis is an uncommon early complication of lung transplantation which necessitates emergency surgical revision. Percutaneous correction of such a complication has not been previously reported. We report a patient who had total pulmonary artery occlusion less than 24 hours after right single lung transplantation with successful revascularization achieved by means of percutaneously delivered endovascular stents.

Adult↗
PubMed1995

Balloon aortic valvuloplasty in adults: failure of procedure to improve long-term survival.

OBJECTIVES: This study sought to determine the long-term outcome of adult patients undergoing percutaneous balloon aortic valvuloplasty. BACKGROUND: Percutaneous balloon aortic valvuloplasty has been offered as an alternative to aortic valve replacement for selected patients with valvular aortic stenosis. Although balloon aortic valvuloplasty produces an immediate reduction in the transvalvular aortic gradient, a high incidence of restenosis frequently leads to recurrent symptoms. Therefore, it is unclear whether balloon aortic valvuloplasty impacts on the long-term outcome of these patients. METHODS: Clinical, hemodynamic and echocardiographic data were collected at baseline in 165 patients undergoing balloon aortic valvuloplasty and examined for their ability to predict long-term outcome. RESULTS: The median duration follow-up was 3.9 years (range 1 to 6). Ninety-nine percent follow-up was achieved. During this 6-year period, 152 patients (93%) died or underwent aortic valve replacement, and 99 (60%) died of cardiac-related causes. The probability of event-free survival (freedom from death, aortic valve replacement or repeat balloon aortic valvuloplasty) 1, 2 and 3 years after valvuloplasty was 40%, 19% and 6%, respectively. In contrast, the probability of survival 3 years after balloon aortic valvuloplasty in a subset of 42 patients who underwent subsequent aortic valve replacement was 84%. Survival after aortic valvuloplasty was poor regardless of the presenting symptom, but patients with New York Heart Association functional class IV congestive heart failure had events earliest. Univariable predictors of decreased event-free survival were younger age, advanced congestive heart failure symptoms, lower ejection fraction, elevated left ventricular end-diastolic pressure, presence of coronary artery disease and increased left ventricular internal diastolic diameter. Stepwise multivariable logistic regression analysis found that only younger age and a lower left ventricular ejection fraction contributed independent adverse prognostic information (chi-square 14.89, p = 0.0006). CONCLUSIONS: Long-term event-free and actuarial survival after balloon aortic valvuloplasty is dismal and resembles the natural history of untreated aortic stenosis. Aortic valve replacement may be performed in selected subjects with good results. However, the prognosis for the remainder of patients who are not candidates for aortic valve replacement is particularly poor.

Aged↗
PubMed1995

Left ventricular performance improves late after aortic valve replacement in patients with aortic stenosis and reduced ejection fraction.

EF in patients with aortic stenosis and reduced EF who underwent aortic valve replacement did not improve by 1 week postoperatively despite rectification of afterload mismatch. By 6 months, however, EF significantly improved without any further change in ventricular loading conditions. This implies that the benefit from aortic valve replacement (when measured by LV ejection performance) may not be evident until late postoperatively.

Aged↗
PubMed1995

Carcinoid heart disease. Correlation of high serotonin levels with valvular abnormalities detected by cardiac catheterization and echocardiography.

BACKGROUND: Although serotonin has been postulated as an etiologic agent in the development of carcinoid heart disease, no direct evidence for different ambient serotonin levels in cardiac and noncardiac patients has been reported to date. METHODS AND RESULTS: The present study reviews our experience with 604 patients in the Duke Carcinoid Database. Nineteen patients with proven carcinoid heart disease (by cardiac catheterization and/or echocardiogram) were compared with the remaining 585 noncardiac patients in the database with regard to circulating serotonin and its principal metabolite, 5-hydroxyindole acetic acid (5-HIAA). No significant demographic differences existed between the cardiac and noncardiac groups; however, typical carcinoid syndrome symptoms (ie, flushing and diarrhea) were almost threefold more common in the cardiac group (P < .001). Compared with the noncardiac group, heart disease patients demonstrated strikingly higher (P < .0001) mean serum serotonin (9750 versus 4350 pmol/mL), plasma serotonin (1130 versus 426 pmol/mL), platelet serotonin (6240 versus 2700 pmol/mg protein), and urine 5-HIAA (219 versus 55.3 mg/24 h) levels. The spectrum of heart disease among the 19 patients showed a strong right-sided valvular predominance, with tricuspid regurgitation being the most common valvular dysfunction (92% by cardiac catheterization; 100% by echocardiogram). CONCLUSIONS: These data suggest that serotonin plays a major role in the pathogenesis of the cardiac plaque formation observed in carcinoid patients.

Carcinoid Heart Disease↗
PubMed1995

Predictors of outcome of tricuspid valve replacement in carcinoid heart disease.

The cardiac valvular surgical experience of patients in the Duke Carcinoid Database was reviewed to assess operative outcome. Of the 604 patients in the database, 19 patients with carcinoid heart disease were identified by cardiac catheterization or echocardiography, or both. Eight of these underwent tricuspid valve replacement surgery with bioprostheses (2 also had open pulmonic valvuloplasty). Compared with patients medically managed, surgically treated patients were similar with the exception that they had higher right atrial mean (17 +/- 6 vs 9 +/- 4 mm Hg, p = 0.03) and v-wave (27 +/- 6 vs 17 +/- 7 mm Hg, p = 0.04) pressures. Of the 8 surgical patients, 5 (63%) died within 30 days. Causes of death included tricuspid valve thrombosis, cerebral vascular accident, coagulopathy, renal failure, and intractable right heart failure. High comorbidity was present in all 8 patients. There was a weak trend (p = 0.17) toward lower Charlson comorbidity indexes in survivors (6.7 +/- 0.6) compared with nonsurvivors (7.6 +/- 0.9). Age was significantly lower (p = 0.036) in survivors (46 +/- 13 years) compared with nonsurvivors (69 +/- 4 years). Extended follow-up revealed 2 patients who survived beyond a decade. Review of 47 carcinoid valve replacement cases (Duke Carcinoid Database and 39 published cases) revealed a 30-day mortality of 56% for patients > 60 years of age, and 0% for those < or = 60 years of age (p < 0.0001). Although valve replacement surgery can afford prolonged palliation from carcinoid heart disease, it is associated with a significant mortality risk. Careful preoperative risk stratification by age and comorbidity may provide a means for optimal selection of surgical candidates.

Adult↗
PubMed1995

Transesophageal echocardiographic assessment of reversal of systolic pulmonary venous flow in mitral stenosis.

Transesophageal echocardiography and diagnostic cardiac catheterization were performed in 36 patients with symptomatic mitral stenosis to assess the incidence and significance of systolic flow reversal in the pulmonary veins. Mitral regurgitation was graded by contrast ventriculography, and left atrial pressure was directly measured after transseptal puncture. Pulmonary venous flow was recorded with transesophageal Doppler imaging from the left upper pulmonary vein. Early systolic flow reversal was identified in 11 patients (31%) and began an average of 58 +/- 13 ms after QRS onset. This pattern correlated strongly with the presence of atrial fibrillation or flutter. Late systolic flow reversal was identified in 8 patients (22%), beginning an average of 245 +/- 46 ms after the QRS complex. These patients had higher left atrial V-wave pressure (36 +/- 10 vs 29 +/- 8 mm Hg; p < 0.05) and V-wave peak-X-descent trough (18 +/- 7 vs 11 +/- 5 mm Hg; p < 0.01) than patients without systolic flow reversal. Neither pattern of pulmonary venous flow reversal was related to the severity of angiographic mitral regurgitation. Systolic reversal of pulmonary venous flow is not specific for angiographically severe mitral regurgitation in patients with mitral stenosis. Similar limitations to pulmonary venous flow analysis likely apply to other patient groups with elevated left atrial pressure and poor left atrial compliance.

Adult↗
PubMed1995

The forgotten chamber: the importance of the right ventricle.

Historically, the right heart was viewed as less important than the left heart in the maintenance of normal overall hemodynamic performance. However, there is now considerable evidence that emphasizes the significance of intact right ventricular (RV) function. The RV's anatomy and physiology are reviewed in order to provide insight into how changes in volume can be accommodated within a low-pressure environment and how this contributes to hemodynamic stability. The interdependent relationship between the right and left ventricles is also explored. The contribution of RV performance to overall hemodynamics is best exemplified when the RV becomes diseased. RV infarction, atrial septal defect, and cor pulmonale are used as examples to illustrate the dramatic sequelae associated with RV dysfunction, as well as to identify the RV's specific adaptive mechanisms.

Heart Septal Defects, Atrial↗
PubMed1995

Application of quantitative coronary angiography in a cineless environment: in vivo assessment of a fully automated system for clinical use.

The accuracy and precision of a fully automated quantitative coronary angiography (QCA) algorithm for use in a cineless environment were determined in phantom studies and in an in vivo canine preparation. Imaging studies of 118 coronary segments in six anesthetized dogs were compared with measurements of the diameters of casts of the canine coronary arteries produced in physiologic conditions. Regression analysis of phantom vessel diameters against QCA measurements revealed slopes of 0.94 to 0.96 and r values > 0.99. The results of the in vivo studies showed good correlation with the coronary cast diameter measurements, with a slope of 0.969 and an r value of 0.987 for the sets of measurements. The high degree of accuracy obtained in a model representative of the clinical situation demonstrates that QCA methods can be applied reliably in the clinical arena with current digital imaging technology and without cinefilm.

Algorithms↗
PubMed1995

Does hypotension during dobutamine stress echocardiography correlate with anatomic or functional cardiac impairment?

The development of hypotension during various exercise stress tests has been correlated with the presence of multivessel coronary artery disease and impaired left ventricular contractility. Hypotension may also occur during dobutamine stress echocardiography; however, its anatomic and functional significance remains unknown. As part of an ongoing study of restenosis, dobutamine stress echocardiography and diagnostic cardiac catheterization were performed on the same day in 105 outpatients approximately 6 months after percutaneous coronary revascularization (balloon angioplasty or directional coronary atherectomy) to determine the anatomic and functional significance of dobutamine-induced hypotension. Dobutamine was infused in stepwise increments to a maximum rate of 30 micrograms/kg/min. Hypotension was defined as a reduction in systolic blood pressure of > or = 15 mm Hg. Anatomic abnormalities were defined by quantitative coronary angiography and functional abnormalities by digitized two-dimensional stress echocardiography. Clinical, angiographic, hemodynamic, and electrocardiographic data underwent multivariable regression analysis to determine their ability to predict independently the development of dobutamine-induced hypotension. Dobutamine-induced hypotension was not associated with the presence of severity of coronary artery disease or with echocardiographic wall motion abnormalities. Univariable predictors of stress-induced hypotension included high baseline systolic blood pressure, advanced age, and high left ventricular ejection fraction. Only a high baseline systolic blood pressure contributed independent predictive information in multivariable stepwise logistic regression analysis. Therefore, the development of hypotension during dobutamine stress echocardiography, unlike that during traditional exercise stress tests, is not associated with the presence of significant coronary artery disease or left ventricular dysfunction.

Age Factors↗
PubMed1994

Which media are most likely to solve the archival problem?

The clinical application of quantitative methods for coronary arteriography remains limited, due in large part to the absence of a suitable replacement for cinefilm as the procedure record. The extension to the clinical environment of the validated objective methods which have found such widespread acceptance in clinical research studies is difficult to implement if the time-consuming and variable process for digitization of selected cinefilm frames is required. In addition, the complete integration of the angiographic procedure record with other patient records and procedures stored in a digital data format requires that the angiographic data eventually be converted to a digital format as well. Replacement of cinefilm requires that the media chosen for the task provide at least the same capabilities and preferably improved functions as those provided by cinefilm as a display, transport, and archival media. The demanding set of requirements imposed on the replacement options include high capacity, high acquisition rate, high transfer rate, application in a distributed environment, portability between institutions, and low expense. A true digital solution should also provide immediate access to the results of the angiographic procedure, transfer of image data over digital networks, multiple-user viewing capability, and quantitative analysis on a routine basis for all patients. In fact, a single media may not provide all the capabilities listed above but, rather, different media may need to be used for specialized tasks, i.e. the solution for archival may not be the same that will be employed as the portable patient record. Separation of the archival function from the acquisition/display and portable transfer functions increases the likelihood that cinefilm can be replaced in the imminent future by reducing the demands on a single media. Among the archival options available today are: (1) magnetic disks; (2) analog laser optical disks; (3) digital laser optical disks; (4) digital file-based magnetic tape; (5) digital video magnetic tape. In evaluating each of these alternatives, an accounting is required of how each meets the archival requirements along with an approximate breakdown of cost and readiness for implementation as a clinical solution today.

Angiography, Digital Subtraction↗
PubMed1994

Three-year outcome after balloon aortic valvuloplasty. Insights into prognosis of valvular aortic stenosis.

BACKGROUND: To identify predictors of long-term outcome after balloon aortic valvuloplasty, we analyzed data on 674 adults (mean age, 78 +/- 9 years; 56% were women) undergoing this procedure at 24 clinical centers who had a mean initial increase in aortic valve area of 0.3 cm2. METHODS AND RESULTS: Baseline data included clinical, echocardiographic, and catheterization variables. Follow-up data included mortality, cause of death, rehospitalization, 6-month echocardiography, and functional status. Kaplan-Meier curves and log-rank tests were used to evaluate survival in subgroups. Multivariate Cox regression models were used to identify independent predictors of survival. Overall survival was 55% at 1 year, 35% at 2 years, and 23% at 3 years, with the majority of deaths (70%) classified as cardiac by an independent review committee. Rehospitalization was common (64%), although 61% of survivors at 2 years reported improved symptoms. Echocardiography at 6 months (n = 115) showed restenosis from the postprocedural valve area of 0.78 +/- 0.31 cm2 to 0.65 +/- 0.25 cm2 (P < .0001). With stepwise multivariate analysis, sequentially adding clinical, echocardiographic, and catheterization variables, the overall model identified independent predictors of survival as baseline functional status, baseline cardiac output, renal function, cachexia, female gender, left ventricular systolic function, and mitral regurgitation. Baseline and postprocedural variables were examined to identify which subgroup of patients has the best outcome after aortic valvuloplasty. A "lower-risk" subgroup (28% of the study population), defined by normal left ventricular systolic function and mild clinical functional limitation, had a 3-year survival of 36% compared with 17% in the remainder of the study group. CONCLUSIONS: Long-term survival after balloon aortic valvuloplasty is poor with 1- and 3-year survival rates of 55% and 23%, respectively. Although survivors report fewer symptoms, early restenosis and recurrent hospitalization are common.

Adult↗
PubMed1994

Relief of superior vena cava syndrome due to fibrosing mediastinitis using the Palmaz stent.

Relief of superior vena cava (SVC) syndrome due to non-neoplastic mediastinal disease presents a formidable challenge. Long-term patency of surgically created bypass grafts has been poor, and the morbidity associated with these procedures is substantial. We report a case of SVC syndrome, caused by fibrosing mediastinitis, treated with Palmaz balloon expandable intravascular stents. Intravascular stents are a promising alternative for relief of non-neoplastic SVC obstruction.

Adult↗