Biomedical subjects
Publications and source records attributed to R M Gunnar.
Newer antiarrhythmic agents can control atrial flutter and fibrillation in many patients, although individual episodes may require cardioversion. Catheter ablation is often curative for refractory flutter. Ablation of atrial fibrillation is more difficult, because of its different mechanism. Surgical and catheter-based ablation procedures have been pioneered for fibrillation but remain experimental.
Explore the source record for details and available documents.
OBJECTIVES: This study was conducted to determine whether the long-term administration of fish oil attenuates myocardial necrosis in an occlusion-reperfusion model of myocardial ischemia. BACKGROUND: Omega-3 fatty acids found in fish oil have various biologic properties that may modify myocardial injury caused by severe ischemia and reperfusion. METHODS: Of 21 dogs fed an identical diet, 10 were given supplemental fish oil containing 0.06 g/kg per day of eicosapentaenoic acid for 6 weeks. Under anesthesia and open chest conditions, the left circumflex coronary artery was occluded for 90 min, followed by 6 h of reperfusion. Regional myocardial blood flow was measured with 15-microns spheres before and during occlusion and during reperfusion. The area at risk and infarct size were measured using standard staining techniques. RESULTS: In the dogs receiving supplemental fish oil, the platelet cell membrane content of eicosapentaenoic acid increased from 0.9 +/- 0.56% to 7.1 +/- 4.0% (p < 0.001). Infarct size was 29 +/- 7% in the control group and 13 +/- 3% in the fish oil group (p < 0.05). There was no significant difference in the myocardial area at risk or rate-pressure product between the control and fish oil groups. There was no difference in regional myocardial blood flow between the groups at baseline study or during coronary occlusion and reperfusion. CONCLUSIONS: Dietary fish oil supplementation significantly reduced myocardial infarct size in this model. The difference in infarct size did not appear to be related to dissimilarities in regional myocardial blood flow or determinants of oxygen consumption. Further investigation is needed to determine the nature of the protective mechanisms of omega-3 fatty acids on myocardial infarct size.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
If the activation of the sympathetic nervous system in chronic heart failure is causally related to progressive pump dysfunction, sudden death, and exercise intolerance, then selective blockade of the beta-adrenergic system may prove to be therapeutically beneficial. This report briefly reviews the evidence that there is systemic activation of the sympathetic nervous system in chronic heart failure, postulates mechanisms by which this activation might contribute to the morbidity and mortality of the syndrome, and hypothesizes further regarding how beta blockade may be beneficial in heart failure. The clinical evidence that the use of beta blockers is beneficial in the treatment of chronic heart failure is reviewed.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Repeat coronary angiography was performed in 42 patients 10 years after randomization to medical (n = 21) or surgical (n = 21) therapy for chronic angina. The native coronary arteries were classified into 15 angiographic segments and 3 arterial trunks for analysis of progression of coronary artery disease. The incidence rate of disease progression in coronary segments was 24% and 28% in medically and surgically treated patients, respectively (p = NS). Grafted segments showed a 38% rate of disease progression, which was higher than the 18% rate of for nongrafted segments (p less than 0.001) and the overall rate of 24% for medically treated patients (p less than 0.01). Similarly, 29 (94%) of 31 grafted arteries exhibited disease progression compared with 19 (59%) of 32 nongrafted arteries (p less than 0.01) and 42 (67%) of 63 arteries in medically treated patients (p less than 0.01). In grafted vessels, disease progression occurred more often in arteries proximal (84%) to the anastomosis than in arteries distal (16%) to graft insertion (p less than 0.001). Progression occurred in 46% of proximal segments compared with 23% of distal segments (p less than 0.02). Progression was seen in 23 (55%) of 43 segments with an occluded graft compared with 30 (31%) of 96 segments with a patent graft (p less than 0.02). Ten years after randomization, medically and surgically treated patients showed a comparable rate of disease progression in coronary segments. However, surgical therapy appeared to significantly accelerate atherosclerotic progression in the grafted vessels, especially in the proximal portions. Occluded grafts also correlated with an adverse effect on disease progression.(ABSTRACT TRUNCATED AT 250 WORDS)
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The Loyola Open-Heart Registry is a fully operational database that contains detailed data on approximately 9,000 patients who have undergone coronary bypass or cardiac valve replacement from January 1970 to December 1984. We analyzed the registry data using multivariate discriminant analysis to identify and quantitate those factors that might predict operative mortality (OM) for patients undergoing coronary artery bypass grafts at Loyola University Medical Center: Operative mortality was defined as death within 30 days following surgery. A total of 50 clinical and angiographic variables were analyzed for possible univariate association with operative mortality. Twenty-two variables were found to have significant univariate association with OM, and these 22 variables were subjected to multivariate discriminant analysis. For patients undergoing isolated, elective coronary artery bypass, the factors found to be predictive of OM are age (greater than 70) (F = 11.57), severe (more than six stenoses) coronary artery disease (F = 5.81), diffuse disease (F = 5.54), positive family history (F = 5.17), and number of coronary arteries bypassed (F = 4.78).