The importance of assessing time-course behaviour of abnormal ST/T changes after exercise.

Routine stress electrocardiography has been criticised for yielding too many so-called 'false-positive' results because ST/T changes that develop during and after exercise are prevalent. Recent studies in our institution indicate, however, that the time-course behaviour patterns of these ST/T configurational 'abnormalities' after exercise are different from those reflecting myocardial ischaemia due to epicardial coronary artery disease (CAD). Time-course analysis increases the predictive value of exercise testing and has dramatically decreased the number of asymptomatic subjects or symptomatic patients at low risk of having CAD being subjected to coronary arteriography in our institution. Our method of assessing post-exercise time course patterns of abnormal ST/T are described in detail. Ischaemic ST/T abnormalities have late onset, early offset or early onset, late offset whereas those ST/T changes associated with normal epicardial coronary arteries have late onset, late offset or early onset, early offset post-exercise time course patterns.

Post-exercise time-course analysis of ST segment and T wave changes: an important contribution to the role of stress electrocardiography in aircrew.

Flight surgeons recognize that ongoing vigilance is necessary to detect coronary artery disease (CAD) in aircrew. Regular physical examinations with only a resting electrocardiogram, albeit having a very low predictive value for detection of CAD in asymptomatic subjects, are now widely practised. Routine stress electrocardiography has been criticized for yielding too many so-called "false positive" results because ST/T changes that develop during and after exercise are prevalent. Recent studies in our institution indicate, however, that the time-course behavior patterns of these ST/T configurational "abnormalities" after exercise are different from those reflecting myocardial ischemia due to epicardial CAD. Time-course analysis increases the predictive value of exercise testing and has dramatically decreased the number of asymptomatic aircrew being subjected to coronary arteriography in our institution. Routine exercise electrocardiography provides a reliable, cost-effective means of detecting aircrew with CAD and a baseline for comparison at subsequent examination, and we strongly recommend that it be universally reinstated.

Observer accuracy and confirmation of the important role of abnormal ST/T time course behavior in the evaluation of stress electrocardiograms.

Routine exercise electrocardiography has been criticized for yielding too many so-called "false-positive" results. Recent studies in our institution indicate that evaluation of the time course behavior of ST segment and T wave (ST/T) changes after cessation of exercise differentiates ischemic from non-ischemic ("false-positive") stress electrocardiograms (SEs). Our method of assessing time course behavior is clarified. The principal aim of this study was to determine the accuracy of experienced observers in making this differentiation. Records of consecutive patients undergoing coronary arteriography over a 2 year period were reviewed and 30 with SEs judged positive for ischemia by the widely accepted ST/T configurational criteria alone were selected at random for the investigation. Sixteen subjects had normal coronary angiograms and had therefore previously been regarded as having false-positive SEs. Fourteen patients had at least one significantly (> 70%) stenosed coronary artery which was our yardstick for ruling that true myocardial ischemia, due to epicardial coronary artery disease (CAD), was present. Five observers, familiar with post-exercise ST/T time course patterns, independently and "blindly" analyzed all 30 configurationally abnormal SEs. Observers were informed only of the patient's age and sex; they were thus unaware of symptoms, exercise variables, coronary anatomy and the number of patients in the 2 groups. The observer consensus for ischemia of SEs using time course analysis was: total test accuracy 87%, sensitivity 79%, specificity 94%, positive predictive value 92% and negative predictive value 83%. Because all 30 patients had ST/T abnormalities, results of the sample for ischemia based on configurational criteria alone were sensitivity 100%, specificity 0% and positive predictive value 47%. We concluded that time course analysis plays a crucial role in evaluating SEs and that exercise electrocardiography remains a safe, cost-effective and reliable method of screening many asymptomatic, as well as symptomatic, subjects for CAD.

Effects of therapy with diet and simvastatin on atherosclerosis in hypercholesterolemic patients.

We evaluated the effect of cholesterol reduction on atherosclerotic coronary artery lesions using diet and simvastatin, a potent HMG CoA reductase inhibitor. Fifteen subjects aged 28-69 years (mean 44), each of whom demonstrated significant (greater than 50%) narrowing of a coronary artery and a baseline cholesterol level greater than 278 mg/dl, were studied. Coronary arteriography was performed prior to and after 20 +/- 2.5 months of therapy. A 42% reduction in total serum cholesterol, a 52% reduction in LDL cholesterol, and an 87% increase in the HDL/LDL cholesterol ratio (p less than 0.01) were achieved. Pretreatment and posttreatment angiograms were reviewed by three experienced angiographers with temporal order masked. Improvement in the overall status of coronary atherosclerotic lesions was demonstrated in two patients (13%), while deterioration occurred in one patient (7%). No overall change was found in the remaining 12 patients (80%). We conclude that a cholesterol-lowering regimen using a nonatherogenic diet and simvastatin therapy may at least stabilize coronary atherosclerosis.

Left anterior hemiblock in South African aircrew.

Serial ECGs and clinical records were examined to determine the prevalence, associated ECG abnormalities and outcome of left anterior hemiblock (LAH) in 13,037 airmen. The prevalence of LAH was 0.72% and it was not related to underlying cardiac disease. LAH should be regarded as a benign finding in healthy individuals.

Safety, tolerability and efficacy of acipimox in type II hyperlipidaemia.

Twenty-one patients with type II hyperlipidaemia were treated with the nicotinic acid analogue, acipimox (Olbetam; Farmitalia), for 6 months. Total cholesterol decreased by 10% and the high-density lipoprotein: low-density lipoprotein cholesterol ratio increased by 13%. Triglycerides were unaltered. Two patients stopped the drug after developing gastro-intestinal side-effects. Acipimox therapy warrants ongoing use and further investigation.

Angiosarcoma of the breast. A case report.

A case of angiosarcoma of the breast in a 39-year-old black woman is described and the presentation, management and clinical course of this rare tumour are discussed.