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Biomedical subjects

G C Oliver

Publications and source records attributed to G C Oliver.

At least 55 records · Page 3Linked to original sources
PubMed1976

Surgical treatment of unstable angina by saphenous vein and internal mammary artery bypass grafting.

During a 3 year period, direct myocardial revascularization was performed on an urgent basis in 48 patients with intermittent resting chest pain which persisted more than 24 hours despite in-hospital medical therapy and was accompanied by electrocardiographic changes representative of ischemia. Sixteen patients had saphenous vein (SV) grafts exclusively, and 32 patients each had one or two internal mammary artery (IMA) grafts with or without additional vein grafts. Follow-up ranges from 5 to 41 months (mean, 22 months). Twelve patients had single grafts to the left anterior descending coronary artery (LAD), 18 had double grafts, 16 had triple grafts, and 2 had quadruple grafts. The LAD required grafting in every patient. There was one operative death (2 per cent) and one late death from noncardiac causes. There were two (4 per cent) early postoperative myocardial infarcts and no late infarcts. Actuarial analysis projects a survival rate of 96 per cent 3 years postoperatively. Eighty-one per cent of the survivors are in Functional Class I, 17 per cent are in Class II, and 2 per cent are in Class III. All patients had postoperative angiography 2 weeks after operation. Eighty-six per cent of the SV grafts and all IMA grafts were open. No significant differences were observed between mean preoperative and postoperative left ventricular end-diastolic pressures or ejection fractions, but these parameters were noted to improve after operation in several patients. The remarkably high early and late survival rates, the low incidence of myocardial infarction, and the excellent functional results after rather long follow-up indicate that emergency coronary revascularization provides an effective therapy for unstable angina. The use of IMA grafts, when feasible, is a safe and possibly preferable approach in these patients.

Adult↗
PubMed1976

Relations between enzymatically estimated myocardial infarct size and early ventricular dysrhythmia.

The relation between ventricular dysrhythmia during the first 20 hours after hospitalization for acute myocardial infarction and enzymatically estimated infarct size was studied prospectively. The duration of dyshythmia was measured by the total time during which the average premature ventricular depolarization (PVC) rate was above 25 PVCs/hr. This index was significantly correlated with infarct size index (ISI) and the strength and significance of the correlation increased when patients with previous, remote myocardial infarction were excluded. An initially expected correlation between PVC frequency and average heart rate was not observed. In a subset of patients selected to include the entire range of ISI, median PVC coupling interval did not correlate with ISI or heart rate. Our results confirm the general reduction of PVC frequency with time after hospital admission. An analysis of total lidocaine administered for therapeutc purposes and dysrhythmia evaluated by retrospective computer analysis disclosed a moderately strong and significant correlation. These findings indicate that persistence and severity of ventricular dysrhythmia in the first 20 hours after hospitalization for myocardial infarction are related to enzymatically estimated infarct size.

Adult↗
PubMed1975

Relation between infarct size and ventricular arrhythmia.

In order to determine whether ventricular arrhythmia is quantitatively related to infarct size estimated enzymatically we studied 31 patients with acute myocardial infarction without cargiogenic shock. Infarct size index was estimated from hourly serum creatine kinase (CK) changes during periods of 48 to 72 hours. Ventricular arrhythmia was quantified by automated analysis of continuous electrocardiographic recordings over a period of 20 hours with the use of the Argus/H computer system. Patients were classified into three groups according to infarct size index. Patients in all groups had similar average heart rate, blood pressure, serum potassium, and arterial pH and PCO2 values during the first 10 hours after admission. The total number of ventricular ectopic beats (VEB), frequency of couplets, and ventricular tachycardia, and peak rate of ventricular ectopic beats during the first 10 hours after admission were all related to infarct size index. For example, patients with small, medium, and large estimated infarct size averaged 26, 104, and 405 ventricular ectopic beats, respectively. These results suggest that the severity of ventricular arrhythmia early after myocardial infarction is related to the extent of myocardial injury as estimated enzymatically. Thus the apparent efficacy and therefore the evaluation of antiarrhythmic agents early after myocardial infarction may be influenced by the magnitude of injury sustained by the heart.

Arrhythmias, Cardiac↗
PubMed1970

Abnormal left heart function after operation for atrial septal defect.

Post-operative data have been presented in seven patients with atrial septal defect. In five of them, residual patency of the atrial septum was found at cardiac catheterization, but in two the defect had been closed. All showed evidence of 'left-sided dysfunction', expressed either as an increase in the pulmonary arterial wedge pressure or the left ventricular end-diastolic pressure or both. The reasons for these findings are not clear, though in several there were indications of impaired right ventricular compliance and possible transmission of raised right-sided pressures to the left side of the heart through a still patent atrial septum. This could not, however, be the mechanism in all cases, and dysfunction of the left ventricle has been seen in two patients in whom the defect was securely closed. The cause of this phenomenon in these selected cases remains obscure.

Adult↗
PubMed1968

The measurement of digitoxin in human serum by radioimmunoassay.

A sensitive, specific, and relatively simple immunoassay permitting measurement of pharmacological levels of digitoxin in human serum has been developed. The assay involves binding of (125)I-labeled tyrosine-digitoxigenin (specific activity > 400 mc/mg) by rabbit antibody to digitoxin. Antibody-bound radioactivity is precipitated by addition of a second antibody (goat anti-rabbit gamma globulin), and precipitate radioactivity is measured. Unlabeled digitoxin can be determined by the extent to which it competes with (125)I-labeled digitoxigenin and thus reduces precipitation of radioactivity. Before the assay, unlabeled digitoxin is extracted from serum with chloroform, and the chloroform solution is evaporated to dryness. Quantitation is accomplished by reference to a standard curve in which known amounts of digitoxin are added to normal serum. As little as 1 mmug of digitoxin per ml of serum produces significant reduction in precipitate radioactivity. The sera of 5 patients were analyzed before and after digitalization. A highly significant reduction in precipitate counts in the postdigitalization sera was observed (P < 0.001). Serum digitalis levels were measured in 19 patients receiving no digitalis and in 19 patients taking digitoxin or digitalis leaf. Little of no digitalis-like activity was detected in control sera, whereas serum levels averaged 27 mmug/ml in those on digitalis (range 4-60 mmug/ml, P < 0.001). Patients judged clinically to show digitals toxicity in general had higher levels than those without signs of toxicity. Patients receiving digoxin had little or no detectable digitalis in their serum with this method. In addition to the assay itself, other potential uses of the antidigitalis antibody include treatment of digitalis toxicity and studies on the tissue localization of digitalis.

Antibodies↗