PubMed Health⌕ Search

Biomedical subjects

D C Mullen

Publications and source records attributed to D C Mullen.

At least 37 records · Page 2Linked to original sources
PubMed1978

Selection of patients for coronary bypass surgery.

We have tried to present a rational approach to selection of patients for coronary bypass surgery. An evaluation of both the anatomic and the clinical status of a patient in whom coronary arteriography has been performed, along with consideration of known results of medical and surgical forms of treatment of coronary artery disease in large series, determines which therapy is preferable. In all instances, the goal of treatment is threefold: relief of pain, preservation of myocardium and prolongation of life. In properly selected patients, pain can be relieved by surgery 90% of the time. Preservation of myocardium is a reality in some groups of patients treated surgically. Current data indicate that prolongation of life by coronary bypass surgery occurs in patients with left main coronary or triple-vessel disease, and as more data are collected, other subgroups may be included.

Coronary Artery Bypass↗
PubMed1978

Effect of intra-aortic balloon pumping on nutrient coronary flow in normal and ischemic myocardium.

The effects of intra-aortic balloon pumping (IABP) on myocardial flow distribution were studied in 50 dogs. Cardiac output was controlled by right heart bypass. In each dog the following parameters were measured with and without IABP during normal coronary perfusion and after regional ischemia was induced by anterior descending coronary vein flow by timed collection, and endocardial/epicardial flow ratios by a previously reported thermal washout technique. In nonischemic myocardium, IABP significantly (p less than 0.05) increased mean coronary sinus flow 11.5 percent +/- 5.8 percent (S.D.) and the mean endocardial/epicardial ratio, 17.3 percent +/- 0.28 percent. In the regionally ischemic myocardium, IABP significantly (p less than 0.05) increased mean segmental coronary vein flow 13.9 percent +/- 1.23 percent but decreased the endocardial/epicardial ratio 29.9 percent +/- 1.1 percent. We conclude that in the dog, IABP enhances subendocardial blood flow in perfused but not in ischemic myocardium. Contrary to common suppositions, the increase in collateral blood flow with IABP preferentially supplies epicardial layers in segmental ischemic zones, but may be shunted from the subendocardium.

Animals↗
PubMed1977

Late evaluation of patients undergoing valve replacement with the Björk-Shiley prosthesis.

This study analyzes 484 patients who survived mitral, aortic, or mitral and aortic valve replacement using the Björk-Shiley prosthesis from January, 1970, through December 31, 1974. Long-term follow-up of 1 1/2 to 6 1/2 years (mean, 3.67 yr) was done on 435 patients (98.2%). Eighty to 85% of the patients have improved noticeably. Thromboembolic problems occurred in 6.9%, representing 1.5 emboli per 1,000 patient-months. Anticoagulant bleeding problems occurred in 6.4% of the patients; late mortality was 15%. Actuarial survival curves showed patients at risk to 6 years having a 79% chance of survival. The same analysis according to preoperative New York Heart Association Functional Classification showed a striking reduction in survival in class IV patients. The Björk-Shiley prosthesis is a good choice for valve replacement today. Earlier diagnosis and treatment are needed to obtain better long-term survival.

Adolescent↗
PubMed1977

Prognostic considerations in the management of left ventricular aneurysms.

This report summarizes a four-year experience with 60 patients who had left ventricular aneurysm (LVA) resection and bypass of all significantly diseased coronary arteries, with an operative and late mortality of 3.3 and 8.3%, respectively. Their cardiac catheterizations were reviewed, and the only values that seemed to reflect prognosis were preoperative cardiac index and the presence of absence of septal motion. The lower the cardiac index, the less likely the patient was to do well postoperatively. There were now survivors who had lacked septal motion by left anterior oblique ventriculogram. Patients without septal motion are therefore no longer considered surgical candidates. If septal motion is present, resection of LVA carries no more risk than myocardial revascularization without LVA.

Adult↗
PubMed1977

Coronary artery surgery without global ischemia.

A simple technique for local occlusion of the coronary artery without aortic cross-clamping during the distal anastomosis has been developed. The use of this internal coronary artery occluder, which we developed, represents another step forward in myocardial protection during coronary bypass procedures.

Coronary Artery Bypass↗
PubMed1976

Beneficial metabolic effects of methylprednisolone sodium succinate in acute myocardial ischemia.

The metabolic and hemodynamic effects of methylprednisolone sodium succinate (40 mg/kg body weight) after acute myocardial ischemia were determined in 24 heparinized mongrel dogs. Myocardial ischemia was produced by ligation of the left anterior descending coronary artery. Catheters in the coronary sinus and the vein draining the left anterior descending coronary arterial area were used to collect blood samples from nonischemic and ischemic myocardium. Lactate, pyruvate, glucose, free fatty acids and oxygen were measured in arterial and venous blood from ischemic and nonischemic areas before and 3, 30 and 60 minutes after myocardial ischemia in animals with (Group II) and without (Group I) steroid treatment. In both Groups I and II glucose, lactate, free fatty acids, oxygen and coronary blood flow in nonischemic areas were not significantly changed, whereas glucose uptake in ischemic areas was significantly increased with myocardial ischemia and remained elevated. In Group I lactate uptake in ischemic areas became negative after coronary arterial ligation and remained so; in Group II, it increased after 30 (70%) and 60 (111%) minutes. Free fatty acid uptake in ischemic areas was reduced after myocardial ischemia in Group I, but in Group II it increased after 30 (224%) and 60 minutes (173%), and there was a concomitant increase in oxygen uptake. Pyruvate uptake in nonischemic areas decreased after 60 minutes in Group I, whereas it was reduced after 30 (68%) and 60 minutes (513%) in Group II. The changes were similar in ischemic myocardium. There were no significant changes in hemodynamic indexes. Coronary blood flow in ischemic areas decreased in Group I after myocardial ischemia and further after 30 and 60 minutes, but in Group II it increased after 30 (82%) and 60 minutes (53%). The data indicate that administration of methylprednisolone results in improved collateral blood flow into the infarcted area and a significantly improved metabolic response of ischemic myocardium. The glucocorticoid may also have a direct benefical effect on carbohydrate metabolism and cause the increased pyruvate neccesary to maintain the generation of energy-producing substrates. The results also suggest that methylprednisolone increases cell survival time and results in greater salvage of ischemic myocardium.

Acute Disease↗
PubMed1975

The effect of continued cigarette smoking on the patency of synthetic vascular grafts in Leriche syndrome.

The effects of continued smoking were studied in 187 consecutive patients who underwent aorto-iliac or aorto-femoral grafting because of Leriche disease and who left the hospital with well-functioning grafts. The patients were divided into the following groups: (1) never smoked, (2) stopped smoking after the operation, (3) continued to smoke less than a pack a day and (4) continued to smoke more than a pack a day. The patency of the grafts was evaluated at regular intervals during a follow-up period ranging from 6 months to 10 years. A significant difference in the patency in the favor of the nonsmokers was found, with the "more than one pack a day" group having more than triple the occlusion rate of the nonsmokers, both absolutely and in month-patency time. We recommend that the surgeon make a most sincere effect to induce patients undergoing vascular operations for occlusive vascular diseases to give up smoking. Failure to promise to stop the smoking habit should be regarded as a relatively strong contraindication for surgery in patients not directly threatened with loss of an extremity.

Arteriosclerosis↗