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Biomedical subjects

R L Frye

Publications and source records attributed to R L Frye.

At least 73 records · Page 4Linked to original sources
PubMed1988

Successful treatment of pulmonary embolism and associated mobile right atrial thrombus with use of a central thrombolytic infusion.

Patients with pulmonary embolism and two-dimensional echocardiographic evidence of right atrial thrombus have a high mortality rate despite standard anticoagulation therapy. We used a direct central infusion of streptokinase in three such patients, who subsequently had rapid and complete clinical improvement. In this setting, thrombolytic therapy should be considered an effective therapeutic option.

Adult↗
PubMed1987

The natural history of lone atrial fibrillation. A population-based study over three decades.

From 1950 to 1980, 3623 patients from Olmsted County, Minnesota, were found to have atrial fibrillation. Ninety-seven of these patients (2.7 percent), who were 60 years old or younger at diagnosis, had lone atrial fibrillation (atrial fibrillation in the absence of overt cardiovascular disease or precipitating illness), and their data were reviewed to determine the incidence of thromboemboli. Twenty of these patients (21 percent) had an isolated episode of atrial fibrillation, 56 (58 percent) had recurrent atrial fibrillation, and 21 (22 percent) had chronic atrial fibrillation. The total follow-up period was 1440 person-years, with a mean of 14.8 years per patient. The mean age at diagnosis was 44 years. Nineteen cardiovascular events occurred in 17 patients; 4 patients had strokes thought to be due to emboli from atrial fibrillation, and 4 had myocardial infarctions without overt evidence of previous coronary artery disease. The probability of survival at 15 years was 94 percent among the patients with lone atrial fibrillation. At 15 years, 1.3 percent of the patients had had a stroke on a cumulative actuarial basis. On an actuarial basis, there was no difference in survival or in survival free of stroke among the patients with the three types of lone atrial fibrillation (i.e., isolated, recurrent, and chronic). We conclude that lone atrial fibrillation in patients under the age of 60 at diagnosis is associated with a very low risk of stroke. This suggests that routine anticoagulation may not be warranted.

Adolescent↗
PubMed1987

Coronary artery disease and its management: influence on survival in patients undergoing aortic valve replacement.

Data from 1,156 patients greater than or equal to 30 years of age who underwent aortic valve replacement alone or with coronary artery bypass grafting from 1967 through 1976 (early series) and 227 similar patients operated on during 1982 and 1983 (late series) were reviewed. In the early series, 414 patients (36%) had preoperative coronary arteriography (group 1): group 1A (n = 224) did not have coronary artery disease, group 1B (n = 78) had coronary artery disease but did not undergo bypass grafting and group 1C (n = 112) had coronary artery disease and underwent bypass grafting. The 742 patients in group 2 did not have preoperative arteriography. Operative mortality rates (30 day) in groups 1A, 1B, 1C and 2 were 4.5, 10.3, 6.3 and 6.3%, respectively (p = NS). The 10 year survival in both groups 1 and 2 was 54%; in groups 1A, 1B and 1C it was 63, 36 and 49%, respectively (1A and 1B, p less than 0.01). In the late series, the 227 patients were divided into similar groups (group 1A, n = 73; 1B, n = 32; 1C, n = 99), and 90% had preoperative coronary arteriography. Operative mortality rates (30 day) for groups 1A, 1B and 1C were 1.4, 9.4 and 4.0%, respectively; that for group 2 (no preoperative arteriography, n = 23) was 4.3%. Definition of coronary anatomy by angiography seems important in most patients greater than or equal to 50 years old who are candidates for aortic valve replacement, and bypass grafting is recommended for those with significant coronary artery disease.

Aged↗
PubMed1987

Vasoconstrictor activity of coronary sinus plasma from patients with coronary artery disease.

Vasoactive properties of plasma samples taken from the coronary sinus, a systemic artery and the superior vena cava of 13 patients with angiographically proven coronary artery disease and from 5 patients with normal coronary arteriograms were assayed in vitro by measurement of the changes in tension of rings of isolated canine coronary arteries. Addition of 1 ml samples of platelet-rich plasma from the coronary sinus of patients with coronary artery disease into a 20 ml organ bath induced an initial relaxation followed by sustained constriction in bioassay coronary artery rings with endothelium and only vasoconstriction in rings without endothelium. The vasoconstrictor activity of the coronary sinus plasma showed positive correlation with the severity and extent of coronary artery narrowing. Systemic arterial and venous plasma samples from patients with coronary artery disease and the coronary sinus plasma from patients with no coronary artery disease evoked only endothelium-dependent relaxations. These vasoactive properties of the various plasma samples were similar whether the samples were taken during rest or during supine bicycle exercise. The serotoninergic receptor antagonist methiothepin prevented the vasoconstriction induced by the coronary sinus plasma samples. These data demonstrate that the coronary sinus blood of patients with atheromatous coronary artery disease exhibits vasoconstrictor activity that may be associated with 5-hydroxytryptamine (serotonin), presumably released from platelets.

Adult↗
PubMed1986

Effect of cigarette smoking on survival of patients with angiographically documented coronary artery disease. Report from the CASS registry.

Through a multicenter registry of patients in the Coronary Artery Surgery Study, we prospectively evaluated morbidity and mortality in 4,165 smokers with angiographically proved coronary artery disease, 2,675 of whom continued to smoke and 1,490 of whom quit. At five years, mortality (adjusted by Cox analysis for baseline differences) was 22% for those who continued smoking and 15% for quitters. The relative risk (also from the Cox analysis) for mortality in continuers vs quitters was 1.55 (95% confidence interval, 1.29 to 1.85). The adverse effect of smoking mainly took the form of higher frequencies of myocardial infarction--associated death and sudden death: the frequencies of these events during follow-up in continuers vs quitters were 7.9% vs 4.4% for myocardial infarction--associated death and 2.8% vs 1.5% for sudden death. This study supports the recommendation that patients with coronary artery disease should stop smoking.

Coronary Disease↗
PubMed1986

Seven year survival of patients with normal or near normal coronary arteriograms: a CASS registry study.

The effect on 7 year survival of having a normal or near normal coronary arteriogram was examined using data from the CASS registry of 21,487 consecutive coronary arteriograms taken in 15 clinical sites. Of these, 4,051 arteriograms were normal or near normal, and the patients had normal left ventricular function as judged by absence of a history of congestive heart failure, no reported segmental wall motion abnormality and an ejection fraction of at least 50%; 3,136 arteriograms were entirely normal and the remaining 915 revealed mild disease with less than 50% stenosis in one or more segments. The 7 year survival rate was 96% for the patients with a normal arteriogram and 92% for those whose study revealed mild disease (p less than 0.0001). Nine risk variables recorded at entry were analyzed for predictive value for survival: age, sex, height, weight, history of smoking, presence of absence of mild disease, electrocardiographic response to exercise, family history of coronary heart disease and a history of hypertension. Of these, age, smoking history, presence or absence of disease and a history of hypertension had predictive value.

Adult↗
PubMed1985

Comparison of coronary artery bypass surgery and medical therapy in patients 65 years of age or older. A nonrandomized study from the Coronary Artery Surgery Study (CASS) registry.

We compared the results of coronary artery bypass surgery with those of medical therapy alone in 1491 nonrandomized patients 65 years of age or older. Cumulative survival at six years (adjusted for major differences in important base-line characteristics) was 79 per cent in the surgical group and 64 per cent in the medical group (P less than 0.0001). At five years, chest pain was absent in 62 per cent of the surgical group and 29 per cent of the medical group (P less than 0.0001). Analysis by the Cox proportional-hazards model suggested an independent beneficial effect of surgery on survival (P less than 0.0001). Patients were divided into risk quartiles on the basis of preoperative predictors of survival identified by the Cox model. Surgical benefit was greatest in "high-risk" patients (those in the two quartiles containing patients with the poorest prognosis). Among 234 "low-risk" patients with mild angina, relatively good ventricular function, and no left main coronary artery disease, there was no survival difference between those treated medically and those treated surgically. We conclude that in specific higher-risk subsets of non-randomized patients 65 years of age or older, coronary bypass surgery appeared to improve survival and symptoms in comparison with medical therapy alone. These conclusions must be tempered by consideration of the limitations of nonrandomized studies, particularly since patients in the two treatment groups differed substantially with regard to important base-line characteristics.

Aged↗
PubMed1985

Artificial heart and assist devices: directions, needs, costs, societal and ethical issues.

A Working Group appointed by the Director of the National Heart, Lung, and Blood Institute (NHBLI) has reviewed the current status of mechanical circulatory support systems (MCSS), and has examined the potential need for such devices, their cost, and certain societal and ethical issues related to their use. The media have reported the limited clinical investigative use of pneumatically energized total artificial hearts (which actually replace the patient's heart) and left ventricular assist devices (which support or replace the function of the left ventricle by pumping blood from the left heart to the aorta with the patient's heart in place). However, electrically energized systems, which will allow full implantation, permit relatively normal everyday activity, and involve battery exchange or recharge two or three times a day, are currently approaching long-term validation in animals prior to clinical testing. Such long-term left ventricular assist devices have been the primary goal of the NHLBI targeted artificial heart program. Although the ventricular assist device is regarded as an important step in the sequence of MCSS development, the Working Group believes that a fully implantable, long-term, total artificial heart will be a clinical necessity and recommends that the mission of the targeted program include the development of such systems. Past estimates of the potential usage of artificial hearts have been reviewed in the context of advances in medical care and in the prevention of cardiovascular disease. In addition, a retrospective analysis of needs was carried out within a defined population. The resulting projection of 17,000-35,000 cases annually, in patients below age 70, falls within the general range of earlier estimates, but is highly sensitive to many variables. In the absence of an actual base of data and experience with MCSS, projection of costs and prognoses was carried out using explicit sets of assumptions. The total cost of a left ventricular assist device, its implantation and maintenance for a projected average of 4 1/2 years of survival might be approximately $150,000 (in 1983 dollars). The gross annual cost to society could fall in the range of $2.5-$5 billion. Ethical issues associated with use of the artificial heart are not unique. For individual patients these relate primarily to risk-benefit, informed consent, patient selection, and privacy. However, for society as a whole, the larger concern relates to the distribution of national resources.(ABSTRACT TRUNCATED AT 400 WORDS)

Assisted Circulation↗
PubMed1985

Mitral regurgitation due to ruptured chordae tendineae. Early and late results of valve repair.

From 1958 through 1980, 131 patients had repair of ruptured chordae tendineae of the mitral valve; 62% were men. Ages ranged from 5 to 70 years (median 57). Chordae to the anterior mitral leaflet were ruptured in 44 patients (34%), to the posterior mitral leaflet in 85 (65%), and to both leaflets in two patients (1%). The mitral valve was repaired by leaflet plication without resection in 116 patients, plication after wedge resection of the unsupported leaflet in six, Ivalon sponge buttress of the posterior leaflet in three, resuspension of chordae in two, and annuloplasty alone in the remaining four. Mitral valve annuloplasty was performed in addition to leaflet repair in 115 patients (88%). Operative (less than 30 days) mortality was 6.1%. Survival rate of patients dismissed from the hospital was 92% at 5 years and 73% at 10 years. There were no differences in late survival or risk of reoperation for recurrent or residual mitral insufficiency between patients with ruptured chordae to the anterior leaflet and those with ruptured chordae to the posterior leaflet. Survival was significantly better for the group with repair than it was for a group that underwent mitral valve replacement for ruptured chordae during this same time interval (5 year survival rate, 92% versus 72%, p less than 0.003). The incidence of thromboembolism after repair was 1.8 episodes/100 patient-years compared with 8.0 episodes/100 patient-years after replacement. Our data indicate that valvuloplasty is the procedure of choice for most patients with mitral regurgitation owing to ruptured chordae tendineae, including selected patients with ruptured chordae to the anterior leaflet.

Adolescent↗
PubMed1984

Randomized, placebo-controlled study of the effect of verapamil on exercise hemodynamics in coronary artery disease.

At cardiac catheterization, 16 patients with coronary artery disease (14 men and 2 women) were allocated by a random, double-blind method to intervention with placebo (saline solution) or verapamil (0.2 mg/kg total by bolus and by 10-minute infusion). In all patients, resting and exercise (3 minutes with a bicycle at 150 kg X m/min) hemodynamic values were obtained during a control period and after intervention. Subsequent left ventriculography and coronary arteriography revealed a mean ejection fraction of 52 and 53% and the mean number of diseased vessels (3-vessel scale) of 2.1 and 1.5 in the placebo and verapamil groups, respectively. In both groups of patients, exercise induced significant increased heart rate, mean arterial pressure, left ventricular end-diastolic pressure and cardiac index. Verapamil increased the heart rate and decreased the mean arterial pressure at rest and the arterial pressure during exercise. It did not affect exercise-induced increases in left ventricular end-diastolic pressure or cardiac index. These results support a role for peripheral mechanisms mediating the antianginal effects of verapamil.

Aged↗
PubMed1984

Primary pulmonary hypertension: natural history and the importance of thrombosis.

A long-term retrospective follow-up study was made of 120 patients (33 male, 87 female patients) with primary pulmonary hypertension--diagnosed by strict clinical and hemodynamic criteria--to obtain a better understanding of the natural history and possible pathogenetic mechanisms of the disease. The mean age at diagnosis was 34 (3 to 64) years, but only 24 patients (21%) remained alive 5 years later. Lung tissue obtained at autopsy from 56 patients revealed two major pathologic types: thromboembolic pulmonary hypertension in 32 patients (57%) and plexogenic pulmonary arteriopathy in 18 (32%). Thus, in more than half the patients undergoing autopsy the major histologic feature was thrombi without any evidence of plexiform lesions. The two groups were similar with respect to their clinical and hemodynamic features and short survival. Of the variables tested for prognostic importance by stepwise multivariate analysis, only two were significant: pulmonary arterial oxygen saturation (p less than .00001) and anticoagulant therapy (p = .01). Anticoagulant therapy is recommended for patients with primary pulmonary hypertension.

Adolescent↗
PubMed1984

Detrimental effect of perioperative myocardial infarction on late survival after coronary artery bypass. Report from the Coronary Artery Surgery Study--CASS.

The influence of perioperative myocardial infarction on late survival after coronary artery bypass grafting was reviewed in 9,777 patients who underwent operation between 1974 and 1979. Definite or probable perioperative myocardial infarction was diagnosed in 561 patients (5.7%). The incidence decreased from 6.6% in 1974 to 4.1% in 1979 (p less than 0.005). Actuarial survival, including hospital deaths, at 1, 3, and 5 years was significantly greater in patients without infarction than in patients with infarction (96%, 94%, and 90% versus 78%, 74%, and 69%; p less than 0.0001). The difference persisted among patients dismissed from the hospital. Reduction in late survival among patients with perioperative infarction was due to the poor outcome of those who had complications (5 year survival rates 40% overall and 73% for patients dismissed from the hospital). Multivariate analysis identified perioperative myocardial infarction as an important independent predictor of late survival after bypass grafting; it was surpassed only by left ventricular function (wall motion score), age, and number of associated medical diseases.

Coronary Artery Bypass↗
PubMed1983

Effect of verapamil on left ventricular function: a randomized, placebo-controlled study.

Verapamil has a negative inotropic action in isolated cardiac muscle. Its effects on left ventricular function were tested in 25 patients with suspected coronary artery disease. A double-blind, randomized, placebo-controlled study design was used. Verapamil (0.2 mg/kg over 10 minutes) significantly lowered mean arterial pressure (from 105 to 89 mm Hg) while increasing the cardiac index (from 2.8 to 3.1 liters/min/m2). No statistically significant effect was seen on heart rate, left ventricular end-diastolic pressure or end-systolic volume index, ejection fraction, peak rates of systolic wall thickening or diastolic wall thinning, or percentage of hemiaxial shortening. However, there was a small increase in the left ventricular end-diastolic volume index (from 94 to 102 ml/m2). Important findings were a reduction in systemic vascular resistance (from 39 to 30 U . m2), an increase in left ventricular end-diastolic volume index consistent with a negative inotropic effect, and no evidence of improved regional wall dynamics in portions of the left ventricular wall considered hypokinetic because of myocardial ischemia.

Cardiac Catheterization↗