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Biomedical subjects

R L Frye

Publications and source records attributed to R L Frye.

At least 109 records · Page 6Linked to original sources
PubMed1980

Histopathological specificity of hypertrophic obstructive cardiomyopathy. Myocardial fibre disarray and myocardial fibrosis.

The topography and specificity of fibre disarray and fibrosis in hypertrophic obstructive cardiomyopathy were determined in a histological study comprising 40 necropsy hearts--10 with hypertrophic cardiomyopathy, 10 with congestive cardiomyopathy, 10 with aortic valve stenosis, and 10 normal hearts. Seven standard regional sections were sampled from each heart and graded "double-blind" (tissue location and disease entity) for severity and extent of fibre dissarray and four distinct types of myocardial fibrosis. Statistical comparison of the severity and distribution of indices of fibre disarray and fibrosis within each group and between the normal and the disease groups showed that fibre disarray and fibrosis were qualitatively non-specific for hypertrophic cardiomyopathy. However, when fibre disarray was quantified (1) it was significantly increased in hypertrophic cardiomyopathy and allowed separation of hearts with hypertrophic cardiomyopathy from normal hearts and from those with congestive cardiomyopathy and aortic stenosis, (2) it did not vary significantly among sections of the left ventricle (that is, between the septum and the free wall) in hypertrophic cardiomyopathy, (3) it was closely associated with plexiform fibrosis, and (4) it varied independently of wall and septal thickness. Though the histogenesis of fibre disarray is unknown, it probably represents an exaggeration of a non-specific common pathway for many diverse pathophysiological processes.

Adolescent↗
PubMed1980

Risk factors and angiographic coronary artery disease: a report from the coronary artery surgery study (CASS).

The findings for 14 risk variables were correlated with the results of coronary arteriography in 8807 patients registered in the interinstitutional Coronary Artery Surgery Study (CASS). Discriminant-function analysis revealed that age, sex, cigarette smoking and the level of blood cholesterol best distinguished between the groups with (6688 patients) and without (2119 patients) coronary artery disease. A family history of coronary artery disease and the presence of hypertension or diabetes were of addition, but less, discriminating value. The relative risk for coronary artery disease in patients with the combination of cigarette smoking and an elevated cholesterol level was high (> 4) in females age 55 years or younger and in males age 35 years or younger. Few females age 45 years or younger (seven of 97) had coronary artery disease when both of these risk factors were absent. In spite of these correlations, only limited gains accrued from the use of discriminant-function analysis in correctly allocating patients into disease and nondisease groups. This indicates that, while certain factors are significantly correlated with coronary arteriographic findings, their value for predicting the presence of coronary artery disease is limited.

Adult↗
PubMed1978

Regional myocardial wall thickening response to nitroglycerin. A predictor of myocardial response to aortocoronary bypass surgery.

The peak rate of systolic wall thickening (p +/- dTw/dt) in regions of the left ventricle (LV) was determined preoperatively by biplane roentgen videometry in 18 patients before and after sublingual administration of nitroglycerin (NTG) and 3-23 months (median 12) after aortocoronary bypass surgery. The regional LV response to NTG was a reliable predictor for postoperative improvement in regional wall dynamics after successful aortocoronary bypass grafting. The ejection fraction response to NTG or surgery will not predict the regional myocardial response to NTG or surgery, nor will the regional response predict the global response. Subendocardial myocardial infarction is another cause of unimproved regional myocardial function after NTG and aortocoronary bypass surgery.

Adult↗
PubMed1978

Relation between left coronary artery stenosis and regional left ventricular function.

The effect of stenosis of the left main and proximal anterior descending coronary arteries on anterior left ventricular wall dynamics was investigated in 70 patients with ischemic heart disease by the use of roentgen videometric analysis of left ventricular angiograms. In all patients with ischemic heart disease, mean values for peak rate of systolic wall thickening and diastolic wall thinning were significantly smaller than normal (P less than 0.01). In patients without infarction, there was no correlation between peak rate of systolic anterior wall thickening and stenosis of the coronary artery supplying it, but there was a significant reduction in peak rate of diastolic wall thinning (P less than 0.01) in patients with stenosis greater than 90%; this difference was not apparent at any lower degree of stenosis. This population could not be recognized by any other parameter of global or regional ventricular function; thus, diastole is more sensitive to regional left ventricular dysfunction than systole.

Adult↗
PubMed1977

Survival predictors in coronary artery disease. Medical and surgical comparisons.

Linear discriminant function analysis was used to test the independent prognostic value of nine variables in patients with coronary artery diseaase. For 68 medically treated patients who met the criteria for inclusion in the discriminant function analysis, the most reliable predictor of 2-year survival status was the left ventricular ejection fraction. The prognostic value of the ejection fraction was not improved by the addition of the number of vessels diseased. Comparisons of the survival of 130 medical and 284 surgical patients were made using subsets based on the ejection fraction. When the ejection fraction was greater than or equal to 50%, the probability of 4-year survival was high for both medical (91%) and surgical (96%) groups. When the ejection fraction was less than 25%, the probability of 2-year survival was low in both groups. However, for patients with ejection fraction 25 through 49%, the surgical patients had a better chance (P less than 0.05) for a 3-year survival (89%) than did medical patients (68%). This study emphasizes the prognostic significance of the left ventricular ejection fraction, which should be considered in any comparison of survival in medically and surgically treated patients.

Age Factors↗
PubMed1977

Complete occlusion of the left main coronary artery and the importance of coronary collateral circulation.

Study of four patients who survived complete occlusion of the left main coronary artery forms the basis of conclusions concerning the functional significance of coronary collateral circulation. Each of these patients had prominent collateral circulation from the right coronary artery. Global left ventricular function was maintained to the extent that congestive heart failure did not occur; the biplane ejection fraction was normal in the two patients where measurement was possible. The peak rate of systolic wall thickening by roentgen videometry in anterior left ventricular segments was normal in one patient and mild to moderately depressed in another. Experience with the patients described herein indicates that coronary collateral flow can provide critically needed circulatory support for the patient with coronary artery disease.

Collateral Circulation↗
PubMed1976

The clinical course, early prognosis and coronary anatomy of subendocardial infarction.

The following prospective study was undertaken to observe the clinical course, early prognosis and coronary anatomy of patients with subendocardial infarction. Subendocardial infarction was defined as typical chest apin (greater than 15 minutes), serum enzyme elevation and persistent (greater than 48 hours) new T wave inversion and/or S-T segment depression in the absence of new pathologic Q waves. Fifty consecutive patients were defined, followed in a prospective manner and subjected to early coronary arteriography. A prior history of unstable angina was found in 33 patients (66 per cent); 22 patients (44 per cent) had significant dysrhythmias during the acute hospital phase, and seven patients (14 per cent) had evidence of mild left ventricular failure. Coronary arteriography demonstrated significant lesions (greater than 75 per cent narrowing in at least one vessel) in all 50 patients, with 30 patients (60 per cent) having either double- or triple-vessel disease. Follow-up (mean 10.6 months) revealed that 15 patients (30 per cent) had stable angina, 23 patients (46 per cent) unstable angina and only 12 patients (24 per cent) remained free of angina. Of 28 patients in a medically treated group, acute transmural infarctions developed in six (21 per cent) and one died (3 per cent). We conclude that subendocardial infarction is symptomatically an unstable entity, is associated with severe coronary artery disease and, in a medically treated group, is followed by a significant incidence of early transmural myocardial infarction (21 per cent). Therefore, these patients require in-hospital monitoring, careful follow-up and consideration for early coronary arteriography.

Adult↗
PubMed1976

Spectrum of echocardiographic findings in bacterial endocarditis.

Forty-seven echocardiograms were obtained in 32 patients with bacterial endocarditis. Preexistent abnormalities were found in 14 patients. In five of them thought to have bacterial endocarditis on normal valves, echocardiography showed mitral stenosis (one), bicuspid aortic valve (two), and prolapse of mitral valve (two). Definite vegetations were seen in 22 patients--on the aortic valve in seven, the mitral valve in 12, and both valves in three. Ten patients had milder changes suggestive but not diagnostic of vegetations. In 12 patients, surgery confirmed the echocardiographic findings. Fourteen had systemic embolic episodes and all had echocardiographic evidence of vegetations. Abnormalities secondary to bacterial endocarditis, other than vegetations, were common. Twenty-one patients had left ventricular volume overload. Ten had a flail posterior leaflet of the mitral valve, three of which were confirmed surgically. Eight had abnormal coarsely fluttering echoes in the left ventricular outflow tract consistent with a prolapsing aortic valve or underlying aortic vegetations; four were confirmed by surgery. Five had signs of severe aortic regurgitation of recent onset (premature mitral valve closure) and all had confirmation by surgery. Echocardiographic abnormalities persisted after successful medical treatment. We conclude that echocardiography is helpful in patients with bacterial endocarditis. It permits recognition of unsuspected preexistent lesions and the characteristic vegetations, as well as the extent and nature of valvular damage secondary to bacterial endocarditis. However, echocardiography does not differentiate between active and healed lesions.

Adult↗
PubMed1976

Videometric analysis of regional left ventricular function before and after aortocoronary artery bypass surgery: correlation of peak rate of myocardial wall thickening with late postoperative graft flows.

The peak rate of systolic wall thickening (pdTw/dt) in regions of the left ventricle was determined by biplane roentgen videometry in 60 patients before and a median of 14 mo after aorto-coronary bypass graft surgery. The left ventricular ejection fraction, stroke volume, and end-diastolic volume and pressure did not change significantly after surgery in the presence of patent or occluded grafts (P greater than 0.05). Statistically significant increases occurred in the peak rate of systolic wall thickening regions supplied by patent bypass grafts, and significant decreases occurred in regions with occluded grafts (P less than 0.01). Of 42 preoperatively hypokinetic regions (pdTw/dt greater than 0 less than 5.0 cm/s) supplied by a patent graft, 30 improved by an average of 2.6 cm/s after operation; 18 returned to normal. Failure of 24 hypokinetic regions to improve to normal was associated with myocardial infarction in 11 or with late postoperative graft blood flows of less than 60 ml/min measured by videodensitometry, in 10. All seven preoperatively akinetic (pdTw/dt=0) or dyskinetic (pdTw/dt less than 0) regions did not improve after the operation despite the fact that, in five of the seven, coronary bypass flows were over 60 ml/min. All eight preoperatively hypokinetic regions supplied by coronary artery graft flows of less than or equal 40 ml/min failed to improve to normal after operation. All nine preoperatively hypokinetic regions supplied by coronary artery graft flows of over 60 ml/min improved to normal after surgery. Late postoperative coronary artery bypass graft flows, the functional status of the myocardium, the status and distribution of the native coronary circulation, and decreased regional function elsewhere in the ventricle must all be considered when regional left ventricular function is interpreted.

Adult↗
PubMed1976

One-year graduated exercise program for men with angina pectoris. Evaluation by physiologic studies and coronary arteriography.

Eight men, 45 to 50 years of age, with mild stable angina pectoris, participated in a graduated exercise program. Coronary arteriography, left ventriculography, left ventricular hemodynamics at rest and during supine leg exercise, treadmill testing with electrocardiographic monitoring, and measurement of oxygen uptake were obtained before and 1 year after the exercise training program. No change was noted in the arteriographic appearance of coronary artery lesions or of collateral circulation. Left ventricular performance, assessed by qualitative left ventriculography and the hemodynamic response of the left ventricle to supine leg exercise, was unchanged after the training program. Oxygen consumption for a given repetitive work load during treadmill exercise decreased. Two patients with a pretraining exercise ECG positive for ischemia reverted to a normal response after the exercise program. All had a decrease in angina, an increase in self-esteem, and a more positive attitude toward their work and their disability.

Angina Pectoris↗
PubMed1975

Regional left ventricular wall dynamics before and after sublingual administration of nitroglycerin.

Regional wall dynamics of the left ventricle before and after sublingual administration of 0.6 mg of nitroglycerin were determined from left ventricular angiograms in 27 patients undergoing coronary arteriography. Regional wall dynamics were quantitatively measured from 60/sec determinations of wall thickness and derived peak rate of systolic wall thickening (peak dTw/dt) in selected sites of the left ventricle. A total of 70 regions were studied. Analysis of the same segment before and after administration of nitroglycerin revealed that the mean change in peak dTw/dt was +1.97 cm/sec in segments with an initial peak dTw/dt of less than 5 cm/sec, in contrast to a change of +0.66 cm/sec in segments with an initial control value of 5 cm/sec or greater. Akinetic or dyskinetic areas did not show improvements after nitroglycerin. In 11 left ventriculograms, an area that was initially hypokinetic manifested an increase in rate of wall thickening after nitroglycerin. The mean increase in peak dTw/dt in anterior segments with electrocardiographic evidence of myocardial infarction was 0.18 cm/sec (P less than 0.05) after nitroglycerin, compared with a mean change of 1.33 cm/sec in anterior segments without such evidence. This study presents evidence for a regional myocardial response to nitroglycerin with differing responses within the same ventricle apparently depending upon the functional state of the underlying myocardium.

Aged↗
PubMed1975

Relation of intraoperative or early postoperative transmural myocardial infarction to patency of aortocoronary bypass grafts and to diseased ungrafted coronary arteries.

Serial preoperative and postoperative electrocardiograms and vectorcardiograms were obtained in 500 patients undergoing saphenous vein aortocoronary artery bypass graft surgery. Evidence of transmural myocardial infarction was found early postoperatively in 67 patients (13 percent). Age and sex distributions, number of vessels diseased or vessels grafted, and preoperative and postoperative New York Heart Association functional classification (mean follow-up, 26 months) did not differ in the groups with and without infarction. Increased duration of cardiopulmonary bypass time (more than 120 minutes) was slightly greater in the group with infarction (P smaller than 0.05). Multivariate analysis revealed that 60 percent of patients in the group with infarction were identified by a 1st day serum glutamic oxaloacetic transaminase value greater than 100 U/liter; however, for each such patient identified, there was approximately one false positive result. Use of other values (creatine phosphokinase, cardiopulmonary bypass time and total anoxic rest time) did not improve discrimination. Twenty-five percent of all transmural infarctions occurred within the zone of myocardium supplied by a diseased ungrafted artery. In 32 patients with early evidence of transmural mycardial infarction in a zone of myocardium supplied by a grafted artery, postoperative angiography showed as many with patent as with occluded grafts. Of 154 patients in the group without infarction who had early postoperative graft angiograms, 30 (19 percent) had one graft occluded and yet no evidence of transmural infarction by our criteria. Therefore, early postoperative evidence of transmural myocardial infarction as defined in this study is an unreliable indicator of the status of the graft supplying the zone of infarction.

Adult↗
PubMed1975

Arteriographic patterns early in the onset of the coronary syndromes.

Coronary arteriography in 300 patients within one year of onset of symptoms of coronary arterial disease revealed already severe anatomical coronary disease in three patient groups: those with angina pectoris alone (164 patients), with subendocardial myocardial infarction (63 patients), and with transmural myocardial infarction (73 patients). The number of vessels diseased (larger than or equal to 50% obstruction), distribution of obstruction, and degree of stenosis were similar in the three groups. However, total occlusion of at least one artery was much more common in transmural myocardial infarction and in subendocardial myocardial infarction with elevation of enzyme levels. We suggest that such occlusions occurred at the time of the infarction. Similarities in coronary anatomy between patient subgroups with angina (on exercise or at rest and nocturnal) indicate that factors other than coronary anatomy intervene in precipitating the different types of angina. Vessel disease was not related to smoking, hyperlipidaemia, or hypertension but coronary disease was manifest earlier in life in smokers or those with hyperlipidaemia.

Adolescent↗
PubMed1975

Perceptions and behaviors of dogmatic subjects in a T-group setting.

Ss scoring 1 SD above or below the mean of the Rokeach Dogmatism Scale, Form E participated. During 12 hr. of training, Ss' behaviors were recorded by observers and each S was periodically rated by his peers on his perceived level of contributions to the group process. Significant differences were found between high and low dogmatics in the behaviors exhibited during the T-groups. Low dogmatics were more self-revealing, more attentive to the here-and-now aspects of the T-group, less apt to give negative feedback, and less likely to reject the group. A significant curvilinear relation was found between peer ratings and behavior in the T-group, with Ss who were rated extremely by their peers being more self-revealing, more attentive to the here-and-now of the group, more apt to give negative feedback, and less likely to reject the group verbally.

Anxiety↗