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Biomedical subjects

M H Ellestad

Publications and source records attributed to M H Ellestad.

At least 55 records · Page 3Linked to original sources
PubMed1986

The cardiointegram: detection of coronary artery disease in males with chest pain and a normal resting electrocardiogram.

The cardiointegram is a non-invasive technique for the analysis of the electrical signals of the heart obtained by a transformation of the voltage vs. time format by a series of integrations. This multicenter study compares the results of the cardiointegram with coronary arteriography in 140 male patients with chest pain and a normal resting electrocardiogram. The cardiointegram was determined on two resting complexes of Leads I, II, V4, V5 and V6 and called abnormal if greater than or equal to four of ten complexes were abnormal, i.e., fell outside of a previously determined template of normality. The sensitivity was 73% and specificity was 78% for the diagnosis of occlusive coronary artery disease. When greater than or equal to five of ten abnormal complexes were used as the cut-off for an abnormal test and "equivocal" results (four of ten abnormal, n = 18) were excluded from analysis there was a sensitivity of 69% and specificity of 88%. Thirty-seven of 38 patients (97%) with an abnormal cardiointegram and a positive exercise stress test had coronary artery disease. Thus, the cardiointegram appears to be a useful non-invasive test for the detection of coronary artery disease in males with chest pain and a normal resting electrocardiogram in whom the diagnosis of coronary artery disease is being considered.

Angiocardiography↗
PubMed1985

Does exercise alter anaerobic threshold in coronary artery disease during beta blockade?

The effect of propranolol on cardiac patients undergoing exercise training is reported to increase exercise tolerance and maximum oxygen uptake (VO2 max) but its effect on anaerobic threshold (AT) is unknown. It was the purpose of this study to determine the role of exercise training with propranolol on AT in patients with coronary artery disease (CAD). Eight men and one woman with significant (CAD) were selected for this study. Each patient completed a maximum treadmill stress test (MTST) following the Bruce protocol on propranolol 40-160 mg/day as a control study. Cardiorespiratory variables were measured at rest and at each stage of the treadmill test. These patients underwent an exercise training programme for 12-16 weeks on the same dose of propranolol. Training sessions were for a minimum of 30-40 minutes, 3 times a week, with training heart rate of 75%-85% of the pretraining peak heart rate. Training heart rate ranged from 98 to 128 beats/min. They were retested with a MTST after the training programme, on the same dose of propranolol. AT was calculated noninvasively by measuring respiratory variables every 30 seconds in relation to work increment. AT was identified by measuring the time course of VE, VCO2, VE/VO2, etc. in relation to incremental work. The mean values of VO2, O2P and % VO2 max at AT before and after training on propanolol were as follows: VO2 = 1.43 L/min +/- .25 and 1.86 L/min +/- .44, O2P = 14.35 +/- 2.40 and 18.73 +/- 4.00 ml/beat, % of VO2 max = 68.20 +/- 6.31 and 73.59 +/- 5.84. The mean changes of VO2 O2P, and % of VO2 max were + 0.43 L/min +/- 0.20 (P < .003), + 4.38 +/- 2.55 (P < .003) and +/- 5.07% +/- 4.84 (P < .001). After exercise training on propanolol, the mean peak exercise tolerance time and absolute VO2 max increased by 2.8 min (from 9.0 to 11.8 min) (P < .001) and 22.7% (P < .007), respectively. We conclude that the increase in anaerobic threshold in patients with coronary artery disease may be due to improvement in VO2 max, increased stroke volume, and peripheral O2 extraction.

Body Weight↗
PubMed1984

Naloxone and asymptomatic ischemia: failure to induce angina during exercise testing.

Endorphins and endorphin receptors are believed to modulate pain perception. To investigate whether naloxone, a specific antagonist, could initiate anginal pain during exercise-induced myocardial ischemia in asymptomatic patients with angiographically defined coronary artery disease, a single-blind trial was conducted in 10 men with prior positive exercise electrocardiograms. Multistage treadmill exercise tests were performed twice within a week. On the second test, patients received naloxone, 2 mg intravenously, by a syringe infusion pump. Exercise was terminated because of fatigue in 6 patients and completion of the protocol in 4. No patient reported chest pain during exercise. Naloxone did not significantly alter exercise duration, heart rate, blood pressure and ST-segment changes compared with control testing. It is concluded that endorphins do not play a significant role in the recognition of anginal pain in patients who have asymptomatic exercise-induced ischemia.

Aged↗
PubMed1984

Comparison of the multivariate analysis and CADENZA systems for determination of the probability of coronary artery disease.

The accuracy of 2 discriminate systems for diagnosis of coronary artery disease (CAD), multivariate analysis (MVA) and Bayesian analysis (CADENZA), was evaluated in 113 patients undergoing electrocardiographic stress testing and coronary angiography. MVA uses weighting factors (F values) generated from our patient data, whereas CADENZA uses probabilities gleaned from an extensive review of the American literature. Overall accuracy was similar. MVA had a higher sensitivity for 1-vessel CAD (75 versus 33%), but CADENZA was better for determining the severity of CAD. The 2 systems provided posterior probabilities for disease that were highly correlated (r = 0.56; p less than 0.001). Both systems suggest the need for further testing based on the probability generated; herein lies their major strength. The application of such systems should help the clinician reach a diagnosis or make a decision as to management in a cost-effective manner.

Bayes Theorem↗
PubMed1984

Coronary artery bypass surgery morbidity.

A retrospective analysis was undertaken of 365 consecutive patients, 75 women and 290 men with a mean age of 59.9 +/- 9.7 years, who had coronary artery bypass surgery during 1981. Complications classified as major were: mediastinal hemorrhage, pericardial tamponade, wound dehiscence, sternal osteomyelitis, myocardial infarction, bacterial endocarditis, dissecting aneurysm and diabetes insipidus. Complications classified as minor were: atrial fibrillation, postpericardiotomy syndrome, cellulitis, thrombophlebitis and phrenic nerve palsy. There were 48 patients (13%) with 52 major complications. Age more than 60 years, cardiopulmonary bypass time longer than 150 minutes, aortic cross-clamp time longer than 100 minutes, number of grafts greater than five and presence of diabetes mellitus were significantly associated with major complications. Complications tended to occur more frequently in women, obese patients and those with emergency operation or ejection fraction less than 30%, but the associations were not statistically significant. Physicians referring patients for coronary artery surgery should be cognizant of the incidence of morbidity along with the other risks and benefits when considering coronary artery bypass surgery.

Adult↗
PubMed1984

Status of exercise stress testing after myocardial infarction.

The use and current limitations of early exercise testing of the patient with a postmyocardial infarction (MI) is reviewed. The test provides useful information in identifying patients at high risk of a second coronary event, thereby helping direct possible interventional therapy. It also furnishes information regarding the patient's capacity for physical exertion, detection of ventricular arrhythmias, and extent of coronary artery disease. Angina, ST segment responses, BP, and ventricular arrhythmias during early exercise testing are evaluated for their importance in determining prognosis. The concomitant use of thallium scintigraphy and radionuclide ventriculography seems to augment detection of multivessel disease and left-ventricular dysfunction. A practical strategy for the use of early exercise testing in the evaluation of post-Mis is provided.

Angina Pectoris↗
PubMed1984

The exercise test as a guide to management and prognosis.

The exercise stress test is one of the most useful procedures available in the management of ischemic heart disease. It can provide a good deal of information, in addition to ST segment changes, for the clinician to interpret. Analysis of test results allows more accurate diagnosis, estimation of the severity of disease, and establishment of prognosis.

Angina Pectoris↗
PubMed1983

Transient central diabetes insipidus after aortocoronary bypass operations.

Three cases of transient central diabetes insipidus after cardiopulmonary bypass are presented. All 3 patients responded promptly to administration of vasopressin, and were completely recovered from polyuria 10 days after cardiac surgery. It is postulated that transient diabetes insipidus after cardiac operation occurred in some patients who had preexisting selective osmoreceptor dysfunction when cardiac standstill during extracorporeal circulation alters the left atrial nonosmotic receptor function, resulting in suppression of antidiuretic hormone release.

Arginine Vasopressin↗
PubMed1983

Cardiac rupture following intracoronary streptokinase.

Thrombolytic dissolution of coronary artery thrombus has added new dimensions to early myocardial infarction treatment. Reperfusion via streptokinase infusion has been shown to be beneficial; however, adverse effects are being noted. We present the case of a patient so treated who subsequently developed left ventricular free wall rupture.

Coronary Disease↗
PubMed1983

Use of multivariate analysis to improve the accuracy of radionuclide angiography with stress in detecting coronary artery disease in men.

A multivariate analysis (MVA) system was derived retrospectively from a population of 76 males with coronary artery disease and 18 control subjects. Posterior probabilities were then derived from such a system prospectively in a new male population of 11 subjects with normal coronary arteries and hemodynamics and 63 patients with coronary artery disease. The sensitivity was 84% compared to that for change in ejection fraction (delta EF) greater than or equal to 5 criterion of 71% (p less than 0.01), the specificity was 91% compared to 73% for the delta EF greater than or equal to 5 criterion (p greater than 0.05), and the correct classification rate was 85% compared to 72% for the delta EF greater than or equal to 5 criterion (p less than 0.01). The significant variables were: change in EF with exercise, percent maximal heart rate, change in end-diastolic volume (delta EDV) with exercise, change in R wave, and exercise duration. Application of the multivariate approach to radionuclide imaging with stress, including both exercise and nuclear parameters, significantly improved the diagnostic accuracy of the test and allowed for a probability statement concerning the likelihood of disease.

Adult↗
PubMed1983

Identification of septal ischemia during exercise by Q-wave analysis: correlation with coronary angiography.

Septal Q-wave amplitudes were studied in lead CM5 to evaluate its utility in predicting segmental coronary artery pathoanatomy. Q-wave amplitudes were measured in 41 patients with coronary artery disease (CAD) before and immediately after treadmill exercise. All patients studied had either significant single-vessel CAD (greater than 70% diameter reduction) or normal coronary anatomy; 13 had left anterior descending (LAD) CAD, 8 had right coronary occlusions, 8 had left circumflex (LC) CAD, and 12 had angiographically normal coronary arteries. Septal Q-wave amplitude measurements at rest and during peak exercise were recorded in 0.5 mm increments and classified as increasing in 20 patients, decreasing in 8, and no change in 13 with exercise. All 13 patients with isolated LAD narrowing had either no change (5 patients) or a decrease (8 patients) in the septal Q wave with exercise. Statistical analysis revealed 62% sensitivity and 100% specificity for single LAD narrowing if a decreasing Q wave was noted with exercise. Patients with isolated right or LC CAD or normal coronary anatomy had mixed septal Q-wave responses to exercise. Only patients with LAD narrowing had reductions in Q-wave amplitude with treadmill exercise. This finding suggests that low Q-wave voltage and its failure to increase after exercise imply abnormal septal activation, reflecting loss of contraction associated with ischemia from LAD narrowing.

Adult↗