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Biomedical subjects

M H Ellestad

Publications and source records attributed to M H Ellestad.

At least 91 records · Page 5Linked to original sources
PubMed1978

Comparison of S-T segment changes on exercise testing with angiographic findings in patients with prior myocardial infarction.

Ninety-seven patients with a prior transmural myocardial infarction who underwent coronary angiography and treadmill stress testing were studied retrospectively to assess the reliability of the exercise electrocardiogram in detecting additional disease in patients with a prior infarction. In patients with a previous inferior wall infarction, the S-T response to the treadmill stress test had a high degree of sensitivity (87 percent) and specificity (90 percent) in detecting additional significant coronary artery disease. However, in patients with a previous anteroseptal wall infarction, the S-T response had much less sensitivity (52 percent), but the degree of specificity remained high (90 percent). In this group a positive test suggested the presence of ischemia in the lateral or inferoposterior region of the myocardium, or both. A negative S-T response was of little value in distinguishing among groups of patients with single or multiple vessel coronary artery disease. The presence of an anterior ventricular aneurysm is most likely responsible for this low sensitivity rate because it generates an opposing force to the ischemic vector, thereby cancelling the S-T segment changes and producing a false negative treadmill stress test. The resting surface electrocardiogram proved useful in predicting a false negative exercise test. The presence of Q waves in the precordial leads extending to lead V4 or beyond decreased the sensitivity rate of treadmill stress testing to 33 percent.

Adult↗
PubMed1978

Coronary sinus pacing clinical follow-up.

Coronary sinus pacing is a safe and effective means of pacing from the atrium. In 66 patients with an average follow-up of 14 months, there was a 14% failure rate. There were transient problems in 14% which were subsequently corrected. There was a 6% death rate which was not pacemaker related. Successful atrial pacing with thresholds up to 6.0 mA is feasible. Atrial pacing was successful in 18 of 19 patients with varying degrees of atrioventricular block. Our experience with a new electrode has been very satisfactory.

Aged↗
PubMed1978

Evaluation of R wave amplitude changes versus ST-segment depression in stress testing.

Exercise ECGs and coronary angiograms were reviewed in 266 patients (81 normals and 185 with significant coronary artery disease). Thirty-three false positive and 96 false negative ST responses to stress testing were purposely chosen to determine if the R wave could reduce the number of false ST responses. R wave amplitude changes were measured in the control and in the immediate postexercise period. An increase or no change in R wave was taken as evidence of an abnormal response, while a decrease in the R wave was a normal response. The sensitivity by ST segment was 48% and the specificity was 59%. These values were low because of the large number of false positive and negative ST responses in the study. It was our purpose to determine if these lowered values could be significantly improved by the R wave. Using R wave criteria, the sensitivity was 63% (P is less than 0.01) while the specificity was 79% (P is less than 0.01). The sensitivity and specificity of stress testing can be significantly improved using R wave changes.

Coronary Angiography↗
PubMed1977

Predictive implications of ventricular premature contractions associated with treadmill stress testing.

Follow-up data on future coronary events was collected on 6,500 patients who had undergone stress testing; 1,327 of these exhibited ventricular premature contractions (VPCs) associated with one or more phases of treadmill stress testing (TSTs). Eighty-three percent of all patients tested had known or suspected cardiovascular disease. The annual incidence of new coronary events (myocardial infarction, angina, cardiac death) during a five year follow-up was 1.7% among 1,067 patients without VPCs or ischemic ST changes, 6.4% in 758 patients with VPCs alone, 9.5% among 609 patients with ischemic ST changes alone and 11.4% in 569 patients with VPCs plus ischemic ST changes. The significance of VPCs associated with the TSTs rests largely upon the clinical status of the persons tested. VPCs observed among patients referred for TSTs for the evaluation of known or suspected cardiovascular disease, with or without ischemic ST abnormalities, represent a definite risk factor for future coronary events.

Coronary Disease↗
PubMed1977

Stress testing in the prognosis and management of ischemic heart disease.

Stress testing is by no means perfect as far diagnosing coronary artery disease, but at this time it is the single best noninvasive method for establishing the presence of ischemic heart disease. From the data shown here, one can see that it adds some important prognostic features as well. The American Heart Association has published a "Coronary Risk Handbook" which can be used to predict the likelihood of a future coronary event by means of accepted risk factors such as hypertension, cholesterol level, and smoking. If we include a positive stress test as a risk factor and compare it to the others, it is clear that a positive stress test has a much higher correlation with future coronary events than any of the other risk factors alone or in combination (Figure 12). Physicians should pay close attention to all of the mentioned factors while carrying out a stress test rather than just looking for ST depression alone. The occurrence of anginal pain, the time of onset, the degree of ST depression, and the patient's pulse and blood pressure response are all useful in assessing the degree of coronary involvement and in predicting an individual's chances of suffering some form of coronary event.

Angiography↗
PubMed1976

Upsloping S-T segments in exercise stress testing. Six year follow-up study of 438 patients and correlation with 248 angiograms.

A 6 year follow-up study of 438 patients who underwent maximal treadmill stress testing revealed the following annual incidence rate of coronary events (death, myocardial infarction or onset or progression of angina pectoris): 13 percent in 84 subjects whose stress test produced 2 mm downsloping S-T segment depression, 9 percent in 230 subjects with 2 mm horizontal S-T depression and 9 percent in 124 subjects who had an upsloping S-T segment with 2 mm S-T depression measured 0.08 second from the J point. Coronary angiograms were obtained in another group of 248 subjects who underwent maximal treadmill stress testing. They revealed major (greater than 50 percent) obstruction of two or three vessels in 67 percent of 62 subjects with a downsloping S-T pattern on the stress test, in 60 percent of 116 subjects with horizontal S-T depression and in 57 percent of 70 subjects with upsloping S-T depression. Patients with an upsloping pattern of S-T depression during stress testing had the same incidence of coronary events as those with a horizontal pattern of S-T depression. Upsloping S-T depression should not be confused with isolated J point depression. Subjects with an upsloping segment also had the same incidence of major two or three vessel disease as those with horizontal depression. Subjects with a downsloping pattern has a slightly greater incidence of coronary events and major two or three vessel disease.

Angina Pectoris↗
PubMed1975

Aortic stenosis, angina, and coronary artery disease. Interrelations.

Sixty-nine patients over age 35 with severe valvular aortic stenosis were investigated for concomitant coronary artery disease. Forty (57.9%) had clinical angina pectoris. Sixteen (23.2%) had significant coronary occlusive disease by arteriography. Of those with angina, 13 patients (32.5) had significant coronary arterial obstruction, while in the pain-free group only (10.3%) had occlusive coronary disease. It is concluded that patients with severe aortic stenosis who are free of angina have only a small, but definite, chance of having significant coronary disease.

Aged↗
PubMed1975

Predictive implications of stress testing. Follow-up of 2700 subjects after maximum treadmill stress testing.

Follow-up data on 2700 subjects who had had maximum stress tests were assembled in life tables. A positive test, characterized by ST-segment depression of 1.5 mm, 0.08 sec from the J point, predicted an incidence of some new coronary event of 9.5% a year, as compared with 1.7% in those with a negative test. The incidence of infarction and death was also significantly higher than in the negative responders. Early onset of ischemia occurring at moderate exercise (4 metabolic equivalents-METS) resulted in an incidence of all coronary events of 15% a year, while ischemia first manifested at the seventh minute of exercise (approximately 8 METS) results in an incidence of only 4% per year. The magnitude of ST depression and the age of onset of ischemia failed to influence the incidence of coronary events. A myocardial infarction previous to the test increased the incidence of events in both positive and negative responders. The positives with a previous infarction had more than double the incidence of coronary events than the positive responders with no pre-existing infarction. Those with chronotropic incompetence had a high incidence of coronary events even though the ECG response to exercise was normal.

Adult↗