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T F Heston

Publications and source records attributed to T F Heston.

8 recordsLinked to original sources
PubMed1997

Cardiac risk stratification in renal transplantation using a form of artificial intelligence.

The purpose of this study was to determine if an expert network, a form of artificial intelligence, could effectively stratify cardiac risk in candidates for renal transplant. Input into the expert network consisted of clinical risk factors and thallium-201 stress test data. Clinical risk factor screening alone identified 95 of 189 patients as high risk. These 95 patients underwent thallium-201 stress testing, and 53 had either reversible or fixed defects. The other 42 patients were classified as low risk. This algorithm made up the "expert system," and during the 4-year follow-up period had a sensitivity of 82%, specificity of 77%, and accuracy of 78%. An artificial neural network was added to the expert system, creating an expert network. Input into the neural network consisted of both clinical variables and thallium-201 stress test data. There were 5 hidden nodes and the output (end point) was cardiac death. The expert network increased the specificity of the expert system alone from 77% to 90% (p < 0.001), the accuracy from 78% to 89% (p < 0.005), and maintained the overall sensitivity at 88%. An expert network based on clinical risk factor screening and thallium-201 stress testing had an accuracy of 89% in predicting the 4-year cardiac mortality among 189 renal transplant candidates.

Adult↗
PubMed1992

Gender bias in the evaluation and management of acute nontraumatic chest pain. The St. Louis Emergency Physicians' Association Research Group.

BACKGROUND: Prior studies suggest a gender-based difference in the management of myocardial ischemia in nonacute settings. We examined whether there was a gender difference in the emergency department evaluation and management of patients with acute chest pain. METHODS: A record review from 10 St. Louis metropolitan emergency departments was done on all patients over 35 years old who presented with acute nonpleuritic, nontraumatic chest pain. We reviewed for the presence of cardiac risk factors, prior cardiac disease, time to physician evaluation, and time to initial electrocardiogram. In the patient subgroup admitted from the emergency department with a diagnosis of myocardial infarction or unstable angina, disposition was noted. RESULTS: Women waited longer than men for an initial physician evaluation and an initial electrocardiogram. In the patient subgroup with acute myocardial ischemia, a smaller percentage of women than men (56.0% vs 82.8%) were admitted to an intensive care unit. CONCLUSION: In patients with acute nonpleuritic, nontraumatic chest pain, women were evaluated and managed less aggressively than men.

Acute Disease↗
PubMed1991

Subchondral architecture in bones of the canine shoulder.

The distal scapula and proximal humerus from each shoulder of nine adult dogs were slab-sectioned, cleaned of soft tissues, embedded in white plastic and stained black with a silver stain. These preparations were then photographed for automated, digital, morphometric analysis of subchondral bone structure. Comparison of transverse and coronal sections through the left and right shoulders demonstrated essential isometry of trabecular patterns within each bone. Comparison of the scapula and humerus revealed significant differences in bony architecture. The subchondral plate was an average of 5.6 times thicker under the glenoid fossa than in the opposing humeral head. Deeper trabecular structure also differed with the trabecular bone volume (density) in the humerus being greater than that in the scapula. This difference reflects a greater trabecular density in the humerus with comparable trabecular thickness in both bones. These structural differences are consistent with previous functional studies of the same two bones that revealed greater mechanical stiffness beneath the glenoid fossa and greater hydraulic resistance within the humeral head.

Animals↗