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Biomedical subjects

W C Sheldon

Publications and source records attributed to W C Sheldon.

At least 19 recordsLinked to original sources
PubMed2001

Trends in cardiac catheterization laboratories in the United States.

The Society for Cardiac Angiography and Interventions has periodically published a Directory of Cardiac Catheterization Laboratories in the United States. All known catheterization laboratories are surveyed and certain operational characteristics are queried. These surveys, in 1983, 1987, 1993, 1995 and 1998, have demonstrated a 2.5 fold increase in cardiac catheterization laboratories since 1983, corresponding increases in numbers of physicians that perform procedures, and in the numbers of procedures performed, reflecting advances in cardiovascular medicine and technology. These surveys have also documented the evolution of interventional techniques, and a shift away from film based imaging, to digitally based methods. These data provide a substrate for consideration of national cardiovascular objectives and planning of future resource allocation by cardiovascular physicians and their colleagues.

Cardiac Catheterization↗
PubMed1992

Cardiac catheterization laboratory survey: 1990. Society for Cardiac Angiography and Interventions, Laboratory Performance Standards Committee.

A survey of 117 member cardiac catheterization laboratories was undertaken by the Society for Cardiac Angiography and Interventions. The survey included numbers and types of procedures, both diagnostic and interventional, in adult as well as pediatric age groups. Radiation safety, various laboratory policies, frequency of short stay, and outpatient procedures were tabulated. Report generation, training programs, administrative organization, and laboratory equipment were all included. The results were compared with a 1978 survey. Areas of concern in terms of safety of the patient and possible underutilization of laboratories were identified.

Angioplasty, Balloon, Coronary↗
PubMed1987

Clinical and angiographic features of coronary artery disease after chest irradiation.

Coronary artery disease (CAD) developed in 15 patients at a mean of 16 years (range 3 to 29) after chest irradiation. The mean dose of radiation was 42 +/- 7 grays; irradiation was performed for Hodgkin's disease in 9 patients, lymphoma in 2, breast carcinoma in 3 and cystic hygroma in 1 patient. Mean age was 48 years (range 26 to 63) at diagnosis of CAD; 4 patients were younger than 35 years. Nine were women. Ten presented with angina, 3 with acute myocardial infarction, 1 patient with syncope and 1 with dyspnea. Twelve had no more than 2 risk factors of atherosclerosis. At coronary angiography, 8 had at least 50% diameter narrowing of the left main coronary artery and 4 had severe ostial stenosis of the right coronary artery. Eight patients also had valvular heart disease, 4 pericardial disease and 4 complete heart block. Mean left ventricular ejection fraction was 67 +/- 11% (range 53 to 80%). Nine had undergone coronary artery bypass grafting, but surgery was difficult or impossible in 3 because of severe mediastinal and pericardial fibrosis. Radiation-associated CAD is characterized by a high incidence of left main and right ostial coronary disease and often occurs in women with relatively few conventional risk factors for CAD.

Adolescent↗
PubMed1986

Influence of the internal-mammary-artery graft on 10-year survival and other cardiac events.

We compared patients who received an internal-mammary-artery graft to the anterior descending coronary artery alone or combined with one or more saphenous-vein grafts (n = 2306) with patients who had only saphenous-vein bypass grafts (n = 3625). The 10-year actuarial survival rate among the group receiving the internal-mammary-artery graft, as compared with the group who received the vein grafts (exclusive of hospital deaths), was 93.4 percent versus 88.0 percent (P = 0.05) for those with one-vessel disease; 90.0 percent versus 79.5 percent (P less than 0.0001) for those with two-vessel disease; and 82.6 percent versus 71.0 percent (P less than 0.0001) for those with three-vessel disease. After an adjustment for demographic and clinical differences by Cox multivariate analysis, we found that patients who had only vein grafts had a 1.61 times greater risk of death throughout the 10 years, as compared with those who received an internal-mammary-artery graft. In addition, patients who received only vein grafts had 1.41 times the risk of late myocardial infarction (P less than 0.0001), 1.25 times the risk of hospitalization for cardiac events (P less than 0.0001), 2.00 times the risk of cardiac reoperation (P less than 0.0001), and 1.27 times the risk of all late cardiac events (P less than 0.0001), as compared with patients who received internal-mammary-artery grafts. Internal-mammary-artery grafting for lesions of the anterior descending coronary artery is preferable whenever indicated and technically feasible.

Coronary Artery Bypass↗
PubMed1986

Pituitary apoplexy: a complication of cardiac surgery.

Pituitary apoplexy occurred in 3 patients in the immediate postoperative period following cardiac operation with cardiopulmonary bypass. In this setting, this complication is extremely rare and not widely recognized. Precipitating factors may be related to the extracorporeal bypass apparatus, anticoagulation, low cerebral blood flow, and even anesthetic agents. Neurosurgical decompression can be safely performed in the early postoperative period following open-heart operations.

Cardiopulmonary Bypass↗
PubMed1985

Comparison of stress digital ventriculography, stress thallium scintigraphy, and digital fluoroscopy in the diagnosis of coronary artery disease in subjects without prior myocardial infarction.

Exercise thallium scintigraphy is often used for the diagnosis of coronary artery disease (CAD). Exercise digital subtraction ventriculography and digital subtraction fluoroscopy are new diagnostic procedures with roles that have not been determined. To compare the relative accuracies of the digital techniques with thallium scintigraphy, 97 consecutive patients without myocardial infarction underwent all 3 tests on the day before their scheduled coronary angiograms. Forty-two patients had CAD (more than 50% diameter narrowing of 1 major artery). A fixed or reversible perfusion defect defined an abnormal thallium test response and a segmental wall motion abnormality at rest or with exercise defined an abnormal digital ventriculographic response. Any visualized coronary calcific deposit defined an abnormal digital fluorographic response. The sensitivities of digital fluoroscopy (86%) and digital ventriculography (79%) were significantly higher than the sensitivity of thallium (62%) (p less than 0.05). The specificity of thallium (82%) was not significantly higher than that of either digital ventriculography (72%) or fluoroscopy (67%). The diagnostic accuracies of digital fluoroscopy, digital ventriculography, and thallium were 75%, 75% and 73%, respectively. A logistic regression model showed that thallium and digital fluoroscopy were more accurate in younger patients, whereas digital ventriculography was more sensitive in hypertensive persons and in those not taking beta-blocking drugs. The choice of test depends on disease prevalence, clinical variables (such as age and hypertension) and the importance of functional information obtained from stress testing.

Age Factors↗
PubMed1984

Left ventricular function in coronary artery disease. Evaluation of slope of end-systolic pressure-volume line (Emax) and ratio of peak systolic pressure to end-systolic volume (P/Ves).

Left ventricular function was assessed by measurement of systolic pressure-volume variables and ejection fraction in seven normal subjects (group I), five patients with coronary artery disease and normal symmetric left ventricular wall motion (group II) and eight patients with remote myocardial infarction and segmental akinesia (group III). Left ventricular volumes were obtained from right anterior oblique ventriculograms and pressures from catheter-tip micromanometer (14 patients) or fluid-filled catheters (6 patients) at two different systolic loads. P/Ves was calculated as the ratio of peak systolic pressure (P) to end-systolic volume (Ves) at rest, Emax as the slope of the end-systolic pressure volume line constructed at two systolic loads, and Vo as the volume axis intercept of this line. Emax was significantly (p less than 0.01) lower in patients with segmental akinesia (group III) (5.0 +/- 0.5) than in normal subjects (group I) (10.4 +/- 0.8) or patients with coronary artery disease and normal wall motion (group II) (9.9 +/- 0.8). In contrast, there was no significant difference in P/Ves among the three groups (6 +/- 1.0 in group I, 5 +/- 0.8 in group II, 3.7 +/- 0.5 in group III). Similarly, Ves and Vo failed to separate the three groups. Although ejection fraction was significantly (p less than 0.05) lower in group III (0.56 +/- 0.03) than in groups I and II (0.67 +/- 0.03 in both groups), there was considerable overlap of individual values in the three groups. In eight patients, measurements were repeated during isometric exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Output↗
PubMed1983

Coronary artery surgery in women compared with men: analyses of risks and long-term results.

A surgical experience with 2,445 consecutive women who underwent isolated bypass grafting was analyzed for comparison with 18,079 consecutive men. Severe or unstable angina occurred preoperatively in 60% of women and 45% of men (p less than 0.001). Despite less three vessel disease (44 versus 56%, p less than 0.001) and better left ventricular contraction (normal in 60% of women and 53% of men [p less than 0.001]), women had a higher operative mortality rate (2.9 versus 1.3%). When matched for age, severity of angina and extent of coronary atherosclerosis, women still had twice the operative mortality of men. In matched patients, body surface area was the strongest predictor of operative risk, even when the model was adjusted for gender. When the model was adjusted for body surface area, gender was not an important predictor of operative death. The smaller size of women, rather than their sex, appears to explain the difference in operative mortality. After a mean interval of 2 years, women had a lower overall graft patency rate (76.4%) than men (82.1%) (p less than 0.001). At 5 and 10 years postoperatively, a higher percent of men were angina-free. Yet, survival for women (90.6%) and for men (93.0%) at 5 years, and at 10 years (78.6 and 78.2%, respectively) was not dissimilar.

Adolescent↗
PubMed1982

Mortality related to cardiac catheterization and angiography.

During a 14-month period, 75 deaths occurring in relation to 53,581 cardiac catheterizations were consecutively and prospectively reported to the Registry Committee of the Society for Cardiac Angiography. Three of the patients died several days after their catheterization from an unrelated cause and are excluded from this analysis. There were 21 patients (group I) who arrived at the laboratory in extremis and whose deaths were expected irrespective of the catheterization. Most of these patients suffered from recent myocardial infarctions and cardiogenic shock, or had complex congenital malformations. In 35 patients (group II), a cardiovascular complication occurring during the catheterization resulted in death. In 16 patients (group III) catheterization seemed uneventful, but death occurred suddenly 10 min to 10 h after the procedure. Of these 16 patients, eight had left main coronary artery obstruction greater than or equal to 90%, five had three-vessel disease all with 90% obstructions, one had 2-vessel disease both with 90% obstructions, and who had critical aortic stenosis. The 51 unexpected deaths (groups II and III) were considered to be causally related to the procedure, a mortality rate of 0.10%. Subsets with an increased mortality rate (M), were patients with: a) left main disease greater than 50% (M = 0.94%); b) ejection fraction less than 30% (M = 0.54%); c) NYHA class III or IV (m = 0.24%); d) age over 60 years (M = 0.23%); or e) three-vessel disease (M = 0.13%). In conclusion, catheterization related mortality occurs mostly in patients with far advanced cardiac disease. Nearly 1/3 of the unexpected deaths occurred suddenly after a seemingly uneventful procedure. Close monitoring after catheterization of patients with similar characteristics (left main disease greater than or equal to 90%, or three-vessel disease all greater than or equal to 90%) might disclose avenues for reducing mortality occurring after catheterization.

Adolescent↗
PubMed1982

Results of myocardial revascularization: a 12-year experience.

All 740 patients who underwent isolated myocardial revascularization procedures from 1967 to 1970 at our institution were compared with the first 1000 patients who underwent similar elective operations each from 1971 to 1979. Data from these 9 years were processed through a computerized cardiovascular information registry. In the 1971-1979 period, the patients were older (median age 57 years, compared with 50 years in the 1967-1970 period), more had multivessel disease (90% vs 44%) and more had ventricular asynergy (54% vs 41%). The number of grafts per patient increased from 1.5 to 2.7, and yet morbidity declined in every category except neurologic deficit. The operative mortality rate was 1.1% from 1967 to 1979 and 1.0% from 1971 to 1979. Graft patency was determined in 475 patients from 1967 to 1970, in 533 patients from 1971, in 519 from 1972, in 540 from 1973 and in 408 from 1974. Patency rates after a mean catheterization interval of 21 months were 77%, 77%, 84%, 87% and 87%, respectively. Five- and 10-year follow-ups were completed for the 1967-1970 series and a 5-year follow-up was completed for 1971, 1972, 1973 and 1974 cohorts. The 5- and 10-year actuarial survival rates for the 1967-1970 series were 89.4% and 77.3%, respectively. The 5-year survival rates for the 1971-1974 series were 91.9%, 93.4%, 92.1% and 91.7%. Abnormal ventricular function and incomplete revascularization adversely influenced the mortality rate (p less than 0.05) in all years. The percentage of asymptomatic patients at 5 years was 66%, 65%, 69%, 67% and 74% for the five patient cohorts. Lower risk and a higher 5-year survival rate are attributable to greater technical experience, changing technology and improved management rather than to selection of lower-risk cases. These 5- and 10-year survival rates compare favorably with the reported results of medical therapy.

Actuarial Analysis↗