Biomedical subjects

F J van der Watt

Publications and source records attributed to F J van der Watt.

4 recordsLinked to original sources

PubMed1990

Detecting asymptomatic coronary artery disease using routine exercise testing and exercise thallium scintigraphy in patients with atherosclerotic vascular disease.

ECG-monitored exercise testing has been proposed as a relatively inexpensive and effective means of screening for asymptomatic coronary artery disease in patients presenting for peripheral vascular surgery. Despite the fact that exercise thallium scintigraphy is also dependent on the patient's ability to exercise, using this test in conjunction with ECG-monitored exercise testing may enhance sensitivity and specificity of non-invasive evaluation. Thirty-two patients were subjected to ECG-monitored exercise testing, exercise thallium scintigraphy and coronary angiography. The sensitivity of ECG-monitored exercise testing for detecting coronary artery disease was calculated at 81.8% and the specificity at 87.5%, while the figures for exercise thallium scintigraphy were 73.1% and 33.3% respectively. Using these two methods in combination yielded a predictive accuracy of 90.6%. The only advantage of exercise thallium scintigraphy over exercise ECG appears to be in patients in whom the latter test could not be interpreted or was non-diagnostic.

Adult↗

PubMed1990

Risk factors for atherosclerosis--can they be used to identify the patient with multisystem atherosclerosis?

Risk factors are often used in preventive care programmes to identify the patient at particular risk for developing atherosclerosis. Risk factors for atherosclerosis have also been shown to be linked to the presence of the disease at a given time, a fact that may be helpful when screening for additional atherosclerotic disease in the known arteriopath. Risk factors were recorded in 471 patients admitted to hospital with symptoms of atherosclerosis. In patients admitted primarily with peripheral vascular disease, risk factors linked to the presence of additional coronary artery disease were a family history of ischaemic heart disease (odds ratio = 2.6), the presence of carotid artery disease (odds ratio = 1.9) and high fasting serum triglyceride levels (P less than 0.04). Grouping these factors together using logistic regression, ischaemic heart disease could be predicted with a sensitivity of 72% and a specificity of 43%. Patients admitted with carotid artery disease were more likely to have ischaemic heart disease in the presence of peripheral vascular disease (odds ratio = 1.9) and a raised serum cholesterol level (P less than 0.02), while female gender (odds ratio = 2.9) and an increase in age (P less than 0.001) were linked to an increased prevalence of concomitant atherosclerosis in patients admitted with acute myocardial infarction or for elective coronary artery bypass surgery. Using an age cut-off point, additional atherosclerosis could be predicted with a sensitivity of 32% and a specificity of 88% in these patients.

Adult↗

PubMed1990

Routine exercise testing to detect coronary artery disease in patients with atherosclerotic vascular disease.

The ability of patients with peripheral vascular disease to perform exercise studies on a conventional treadmill is often hampered by claudication, amputation, ischemic ulceration or rest pain. This study was undertaken to investigate the use of the arm ergometer in these patients. Eighty-three patients admitted with peripheral vascular or carotid artery disease were subjected to electrocardiographic-monitored exercise testing, using both the arm ergometer and conventional treadmill, where possible. Coronary arteriography was performed consecutively on 32 of these patients to establish a control group from which the sensitivity, specificity and predictive accuracy of both methods of exercise testing could be calculated. Nineteen of the 70 arm ergometry tests and 22 of the 48 treadmill tests were positive. Nineteen of the patients with a positive test using either of the methods were asymptomatic for cardiac disease. All five patients who developed cardiac events during surgery had positive exercise tests, preoperatively. The sensitivity of arm ergometry in detecting coronary artery disease was 45.5% and the specificity 100%, while the figures for treadmill testing were 82.4% and 83.3%, respectively. The combined sensitivity for the two tests was 81.8% and the specificity 87.5%. Using a combination of these two tests thus provided a highly specific and adequately sensitive means of detecting the presence of coronary artery disease in patients presenting for peripheral vascular surgery.

Adult↗

PubMed1990

The arm ergometer exercise test for evaluating coronary artery status in patients presenting for peripheral vascular surgery.

Various non-invasive methods exist for evaluating the cardiac status of patients presenting for peripheral vascular surgery. Methods involving exercise on a treadmill are frequently used, but adequate testing may be limited in amputees and patients with severe claudication or rest pain. An alternative means of exercise is the arm ergometer. A study of 130 patients subjected to arm ergometer exercise testing before peripheral vascular surgery was undertaken. A control group of 29 consecutive patients had coronary angiography. ECG exercise testing using the arm ergometer showed a sensitivity for detecting coronary artery disease of 46% and a specificity of 100%. In total, 42 tests were positive, 21 on patients with no symptoms of ischaemic heart disease and no resting ECG changes indicative of ischaemia, and 4 in patients with atypical angina. Muscle fatigue proved a problem, especially in women; while the accuracy of the test did not decline in patients over the age of 60 years when compared with those under this age.

Adult↗