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Biomedical subjects

R A Bruce

Publications and source records attributed to R A Bruce.

At least 19 recordsLinked to original sources
PubMed1992

Arthroscopic resection of glenoid labral tears in the athlete: a report of 29 cases.

This article is a retrospective review of 28 overhead-throwing and striking athletes who underwent 29 arthroscopic partial glenoid labral resections. Indications for the procedure were a sudden inability to perform because of pain and the presence of a palpable "click" on clinical examination. At a minimum of 2 years follow-up, there was a statistically significant difference in the functional outcome between patients with stable and those with unstable glenohumral joints. In those with stable joints, there was a 91% good or excellent functional outcome. In those with unstable joints, there was a 25% good functional outcome and a 75% fair or poor functional outcome. We also noted a statistically significant difference in labral tear location between the stable and unstable glenohumeral joints. Seven of eight superior labral tears were in stable shoulders. Fourteen of 19 anterior labral tears were in stable shoulders. Both posterior labral tears were in unstable glenohumeral joints. Injury of the glenoid labrum without anatomic instability was observed in 72% of patients. Arthroscopic resection of a longitudinal labral tear in a stable shoulder can relieve the patient's discomfort and allow him or her to return to athletic competition. No patient developed clinical subluxation as a result of labral debridement, nor did any patient convert from a subluxing shoulder to a dislocating shoulder following surgery. In patients with anterior instability and labral tears, labral debridement was not a successful alternative to formal stabilization.

Adult↗
PubMed1991

Ameloblastic carcinoma. Report of an aggressive case and review of the literature.

Odontogenic carcinomas of the jaws are classified as malignant ameloblastoma, ameloblastic carcinoma or primary intraosseous carcinoma. Because these lesions are extremely rare, microscopic diagnosis is difficult. An aggressive case of ameloblastic carcinoma of the mandible is presented. In spite of radical surgery and radiotherapy, the patient expired eight months following initial diagnosis. - A review of the literature seems to indicate that so called simple ameloblastomas rarely can dedifferentiate and metastasize following multiple inadequate surgical procedures. Although radical surgery is not necessary, local excision should be thorough. - Ameloblastic carcinoma and primary intraosseous carcinomas may be histogenetically similar. They are highly malignant tumours which should be treated aggressively. Metastasis is common and prognosis is poor.

Ameloblastoma↗
PubMed1989

Strategies for risk evaluation of sudden cardiac incapacitation in men in occupations affecting public safety.

Sudden cardiac incapacitation occurring during critically stressful circumstances in men engaged in a variety of occupations may compromise public safety. Since the primary cause of this incapacitation is usually heart disease, more effective medical screening has been advocated. We report the annual incidence of sudden cardiac incapacitation in four clinical groups--4105 healthy men (Group I), 537 men with atypical chest pain syndromes (Group II), 1374 hypertensive men (Group III), and 2373 men with clinically manifest coronary heart disease (Group IV)--who have been examined and tested by maximal exercise with the Bruce protocol in Seattle community practice. Five strategies for prospective risk assessment are presented in these groups, namely age alone, clinical diagnosis before testing, the combination of both parameters, exercise-enhanced risk assessment, and the exercise criteria proposed by a Task Force for Ischemic Heart Disease (Bethesda Conference XVIII, 1986). We conclude that the exercise-enhanced risk assessment is the most effective of these strategies.

Accident Prevention↗
PubMed1979

Comprehensive analysis of exertional ECG changes before and after oral propranolol.

In 12 patients with symptomatic coronary heart disease and three normal persons, comprehensive analyses of the electrocardiographic changes associated with symptom-limited upright exercise are made by computer analysis of the electrocardiogram recorded using a Frank XYZ lead system. This analysis provided a display of the 12 lead ECG, vectorcardiogram, polarcardiogram, and spatial cardiogram and measurements of spatial magnitudes of heart vectors. The effect of 40 mg of oral propranolol was assessed by repeating the exercise protocol 60--90 min later. There is evidence that propranolol reduces the electrocardiographic features of myocardial ischemia. This reduction in myocardial ischemia correlates with reductions in pressure rate product and heart rate. The presence of infarct criteria with exercise is variable and not apparently influenced by propranolol.

Adult↗
PubMed1979

Acute effects of oral propranolol on hemodynamic responses to upright exercise.

Noninvasive measurements of maximal oxygen intake and invasive measurement of systemic and pulmonary arterial pressures, arterial and mixed venous oxygen contents and direct Fick cardiac output are reported for 3 healthy men and 14 men with coronary heart disease. Observations were obtained at supine and sitting rest, during graded levels of upright exercise on a treadmill up to symptom-limited maximal effort and in two periods of recovery. The effects of 40 mg of propranolol orally were ascertained by repeating the measurements 1 to 1 1/2 hours later. The most consistent effect of propranolol was reduction of pressure-rate products at all phases; slowing of heart rate was significant only during exercise and recovery, and the greater slowing was accompanied by a significant increase in stroke volume. These changes were similar in patients with and without evidence of left ventricular impairment greater than 15 percent on exercise testing. Maximal oxygen intake decreased in healthy subjects and decreased slightly in patients with coronary heart disease with less than 15 percent left ventricular impairment or percent deviation of pressure-rate product from age-predicted normal values during the control study. Maximal oxygen intake increased in patients with more than 15 percent left ventricular impairment. Arterial-mixed venous oxygen difference increased after propranolol because of a reduction of mixed-venous oxygen content attributed to greater peripheral extraction of oxygen.

Blood Pressure↗
PubMed1979

Clinical importance of directional statistics for electrocardiographic differentiation of smoking habits.

Statistical methods for the analysis of directional data are of relatively recent origin and have not been generally applied in clinical investigations where they are appropriate. This study compares spherical means and standard deviations for directional polarcardiographic variables with the linear means and standard deviations of the same variables for a typical industrial cohort of male white collar workers. Normal subjects were classified by smoking status and by independent clinical evidence of the presence of CHD, and both directional and linear statistics are applied to compare the PCG variables in these groups. Directional statistics more accurately define the spherical means and variances of heart vectors and thereby permit more reliable differentiation of directions, or angles to aid diagnosis.

Adult↗
PubMed1979

Noninvasive screening criteria for enhanced 4-year survival after aortocoronary bypass surgery.

Two thousand one men with coronary heart disease (CHD) who were enrolled in the Exercise Testing Registry of the Seattle Heart Watch had symptom-limited maximal exercise tests at the initial clinical examination and follow-up surveillance of subsequent mortality for 4.1 +/- 1.6 years. When subdivided into three mutually exclusive subgroups, 636 patients did not have exertional myocardial ischemia, left ventricular dysfunction or cardiomegaly; 885 without cardiomegaly had only exertional ischemia; 480 had left ventricular dysfunction by either cardiomegaly and/or two noninvasive exertional criteria, with or without exertional myocardial ischemia. Three hundred thirty-one men had aortocoronary bypass surgery, while 1670 remained unopened for at least 4 years. Only 34% of the operated patients who had left ventricular dysfunction, as defined, showed a marked improvement in 4-year survival rates (p less than 0.01). Differences in the annual CHD mortality rates in relation to surgical treatment in the other two groups were not statistically significant. Restricting the analysis to a subset of patients who had invasive studies did not alter the conclusion. Accordingly, we suggest the use of noninvasive criteria to aid preliminary screening of patients for invasive studies and surgical treatment.

Adult↗
PubMed1978

Exercise testing as a predictor of heart disease and sudden death.

Analysis of data obtained from symptom-limited exercise testing and standard clinical evaluation has identified certain variables as having marked prognostic significance in coronary disease, making it possible to separate patients at highest risk of sudden death from the vast majority. The way is thus opened for focusing aggressive preventive efforts upon the group most likely to achieve the greatest benefit.

Age Factors↗
PubMed1978

Physiologic improvement following coronary artery bypass surgery.

In this study the effects of coronary artery bypass surgery on ventricular function were evaluated at rest by quantitative analysis of segmental wall motion on cineventriculography, and during maximal treadmill exercise by measurement of serial cardiac outputs (Fick method) with the use of indwelling pulmonary artery and radial artery catheters. The patient had single vessel coronary disease and exertional angina. Following placement of a bypass graft to the proximally occluded left anterior descenting coronary artery, and despite the presence of arterial hypoxemia secondary to interstitial pulmonary fibrosis, a striking increase in maximal cardiac output occurred, mediated by a rise in both maximal heart rate and stroke volume. In this patient, resting ventricular volumes and ejection fraction were normal both before and after surgery, but preoperative abnormalities in extent of segmental wall motion, identified quantitatively, were restored to normal after bypass grafting. These investigations indicate that bypass surgery can provide substantial physiologic benefits in addition to providing subjective relief of anginal symptoms.

Aged↗