Screening for the detection of coronary artery disease by using the exercise tolerance test in a preventive medicine population.

We designed this study to identify patients with coronary artery disease (CAD), employing the exercise tolerance test, and to develop further criteria for ordering the exercise tolerance test in the preventive medicine population of the Cleveland Clinic Foundation. During 1987-1988 1,930 patients not known to have CAD were referred from the Department of Preventive Medicine for exercise tolerance tests as part of their periodic physical exams. We hypothesized that age was a major risk factor and ordered most (86.4%) tests on this basis: at age 40 and every two years after age 50. Twenty-five cases of CAD (25/1,930 or 1.3%) were found. One of 297 women was found to have CAD (0.3%). Seventeen patients were treated surgically and eight medically. Using age as an indication for testing detected 23 of 25 cases (92%). We compared the group with normal or nondiagnostic exercise tolerance tests and presumed not to have CAD (1,905 patients, median age 48) with the group with CAD (25 patients, median age 59). Age greater than 40, a total cholesterol level over 240 mg/dL, triglyceride level over 250 mg/dL, a total cholesterol to high-density lipoprotein ratio greater than 4.5, and a history of chest pain of any type were all significantly related to the presence of CAD. Testing men older than forty with two or more CAD risk factors, as has been recommended, would have resulted in finding five of the 25 cases (20%). Testing only patients who complained of any type of chest discomfort would have resulted in detecting 14 of the 25 cases (56%).(ABSTRACT TRUNCATED AT 250 WORDS)

Fecal occult blood testing. Guidelines for follow-up after positive findings.

Fecal occult blood testing should be performed under optimal conditions to minimize false-positive test results. Obvious bleeding from the rectum or other sources during the test period should be investigated and testing should be postponed. When a fecal occult blood test is positive, colonoscopy is recommended as the definitive method of diagnosis and often of treatment. When a complete colonoscopy cannot be performed, sigmoidoscopy with air-contrast barium enema is the next best alternative for direct visualization of the distal bowel and indirect investigation of the proximal colon.

alpha1-Antitrypsin deficiency in clinic patients.

Five hundred patients undergoing complete medical examination, and 225 consecutive patients with abnormal pulmonary function tests were studied for alpha1-antitrypsin deficiency. Within the first group, respiratory disease was diagnosed significantly more often in patients with a variant Pi phenotype (MS, MZ, FF) than in the patients with the most common phenotype, MM. Furthermore, the frequency of heterozygosity (MS or MZ) was greater in the patients who had respiratory disease. When the first and second groups were compared, the prevalence of the variant phenotypes was not statistically different.

Application of the EXPERT consultation system to accelerated laboratory testing and interpretation.

The EXPERT consultation system-building tool, a knowledge-based artificial intelligence program developed at Rutgers University, has been applied to the development of a laboratory consultation system facilitating sequential laboratory testing and interpretation. Depending on the results of a basic panel of laboratory tests, the system requests that specific secondary tests be performed. Input of these secondary findings can result in requests for tertiary testing, to complete the database necessary for interpretation. Interpretation of all results is based upon final inferences from the collected findings through a series of rules, a hierarchical network that yields an efficient production system not easily obtained through conventional programming. The rules included in this model are based upon initial results for total protein, calcium, glucose, total bilirubin, alkaline phosphatase, lactate dehydrogenase, aspartate aminotransferase, thyroxin, hemoglobin, mean corpuscular volume, and the concentrations of four drugs. Pertinent clinical history items included are jaundice, diabetes, thyroid disease, medications, and ethanol. Implementing this system in a laboratory-based accelerated testing program involving outpatients maximized the effective use of laboratory resources, eliminated useless testing, and provided the patient with low-cost laboratory information.

Alpha 1 antitrypsin deficiency: a study of the relationship between the Pi system and genetic markers.

Twenty-four members (4 generations) of a family with alpha 1 antitrypsin deficiency were studied in an attempt to determine the chromosomal location of the Pi system locus. Three alpha 1 antitrypsin alleles (PiM, PiI, and PiZ) and five phenotypes (MM, MZ, MI, IZ, and ZZ) were detected in family members. The quinacrine fluorescent banding technique was successfully utilized to reveal eight polymorphic chromosomal markers in family members. Eight red cell antigens and HL-A antigens were identified for each family member. No linkage between the Pi system and chromosomal markers, four polymorphic red cell antigens, and HL-A antigens was detected. On the basis of this family study, the Pi locus as defined by alpha 1 antitrypsin deficiency does not appear to be on chromosomes 2, 3, 13, 14, 21, or 22 within measurable distance of the markers used.