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R F Leighton

Publications and source records attributed to R F Leighton.

At least 19 recordsLinked to original sources
PubMed1992

Adherence to exercise interventions in the treatment of hypercholesterolemia.

The goals of this study were to determine the rate of adherence to exercise treatment of hypercholesterolemia and to identify personality and demographic factors associated with adherence. Of the 31 subjects entering the 26-week program, 12 attended 80% or more of the scheduled sessions. Adherence was positively associated with the perceived seriousness of hypercholesterolemia, the expectation of benefit from treatment, and depressed feelings of helplessness and hopelessness. Negative associations were identified between adherence and the perception of health status being under the control of chance or of powerful others. Older subjects were more likely to be adherers at 8 and 16 weeks but not at 26 weeks.

Adult↗
PubMed1992

Cardiology education using hypermedia and digital imagery.

A computer-based educational system for the study of cardiovascular imaging is described. This system, based on HyperCard * and a standard Macintosh II, integrates hypertext retrieval, computer graphics, sound, and medical images into a single interactive environment stored on a standard hard disk. This 'hypermedia' approach allows arbitrary complexity coupled with direct, immediate, easy traversal of the images and related text, which provides the opportunity for students to move at their own pace, choose their own direction through the material and repeat as often as desired. Storage on magnetic medium allows for easy updating with new studies and material in order to keep pace with advances in medical imaging technology. The system could be mastered onto CD-ROM for ease of distribution if so desired. The system includes a tutorial on the basics of digital image representation and example studies from cineangiography, nuclear medicine, echocardiography and magnetic resonance imaging of the heart. Quantitative techniques for evaluation of left ventricular function are explained using computer graphics overlays on the original medical images. Color encoded functional images are also included as an aid to visualization of ventricular performance data. The system has proven useful as a primer for digital imaging in cardiology prior to specific case study in a traditional mentor relationship.

CD-ROM↗
PubMed1990

Management of the patient with a low HDL-cholesterol.

While there is epidemiologic evidence linking a low high-density lipoprotein (HDL) cholesterol level with coronary disease events, and interventions that raise HDL while lowering low-density lipoprotein (LDL) cholesterol levels have been shown to reduce subsequent coronary events, there are no studies showing benefit from raising HDL when a low HDL level is the sole lipid abnormality. HDL is thought to play a key role in reverse cholesterol transport, removing lipids from peripheral cells, but the precise role of HDL in cholesterol metabolism is not understood. The measurement of HDL levels has not been well standardized. Reliance on ratios relating HDL to LDL or to total cholesterol may be misleading in the management of patients. It has not been shown that measuring HDL subfractions or apolipoprotein levels is superior to measuring total HDL levels in predicting coronary risk. HDL levels may be raised by hygienic measures such as smoking cessation and exercise, but a considerable amount of exercise over a long period of time is required. Alcohol consumption and weight loss through dieting inconsistently raise HDL. Estrogen therapy raises and progestational agents lower HDL. Certain beta-blocking drugs lower HDL levels. For the patient with an isolated low HDL level the hygienic measures may be advised, but drug therapy such as nicotinic acid or gem-fibrozil should be prescribed only when low HDL is accompanied by elevated LDL levels that are unresponsive to diet and hygienic measures.

Apolipoproteins↗
PubMed1990

The Toledo Exercise and Diet Study. Results at 26 weeks.

This study was designed to test whether an exercise program is additive to diet counseling in lowering elevated blood cholesterol levels. From a screened population of 1024 subjects, we randomized 66 predominantly female subjects to two intervention groups: diet counseling and diet counseling with exercise. Subjects were selected who had elevated levels of serum low-density lipoprotein cholesterol, an average or low fitness level, and a diet high in saturated fat and cholesterol. After 26 weeks of intervention, 51 subjects exhibited significant decreases in serum levels of cholesterol, high-density lipoprotein cholesterol, triglycerides, and low-density lipoprotein cholesterol. The addition of exercise to diet counseling resulted in improved aerobic capacity, losses of body fat and weight, and further nonsignificant decreases in serum cholesterol and low-density lipoprotein cholesterol levels. Since these results differ from data acquired in individuals with normal to borderline serum cholesterol levels, further studies appear indicated in hypercholesterolemic subjects, especially in women.

Adult↗
PubMed1988

Predictive value of ventricular arrhythmias in resuscitated out-of-hospital cardiac arrest victims.

Twenty-four hour ambulatory electrocardiograms recorded in 103 survivors of out-of-hospital cardiac arrest were analyzed to find those characteristics of the ventricular premature complex (VPC) which provide the best combination of sensitivity, specificity, and predictive accuracy for subsequent mortality. VPC characteristics were grouped as: (1) frequent (greater than or equal to 25 h-1), (2)bigeminal, (3) multiform, (4) early coupled, (5) pairing, (6) repetitive greater than or equal to 2, (7) repetitive greater than or equal to 3, (8) repetitive greater than or equal to 6, (9) the combination of frequent and repetitive, or (10) complex defined as any multiform, early, bigeminal or repetitive VPC. In an average follow-up period of 43 months, 42 deaths occurred, 17 of which were classified as sudden. Each characteristic was a significant predictor for all causes of subsequent death except early coupled VPCs and repetitive VPCs greater than 6. None of the characteristics reached significance as predictors for sudden death. The number of repetitive VPCs when stratified to none, greater than or equal to 2 and greater than or equal to 3 successive VPCs correlated with mortality in an incremental fashion. The combination of frequent VPCs and repetitive VPCs provided the best combination of sensitivity, specificity and predictive accuracy for death from all causes within five years.

Arrhythmias, Cardiac↗
PubMed1987

Comparison of thrombolytic therapy for acute myocardial infarction in rural and urban settings.

In this study, a tertiary care hospital served as a registry and information source to rural hospitals in northwestern Ohio where thrombolytic therapy had not previously been used. The study was designed to compare the safety and efficacy of intravenous thrombolytic therapy for acute myocardial infarction in the two settings. Fifty-five patients in eight rural hospitals and 36 patients in the urban tertiary care center received intravenous streptokinase. Of the 87 patients whose symptoms first occurred out of the hospital, 63 percent were treated within three hours. There were no significant differences in rates of clinically determined coronary artery recanalization (63 percent versus 69 percent for rural and tertiary hospitals, respectively), in-hospital mortality (5.4 percent versus 11 percent), bleeding complications (3.6 percent versus 5.5 percent), or time from the onset of pain to infusion of streptokinase (3.4 hours versus 2.9 hours). There were also no differences in the completeness of collection of serial coagulation data and cardiac enzyme values, or in the documentation of chest pain onset and cessation. Major differences between rural centers and the tertiary care center involved the use of serial electrocardiography (58 percent versus 89 percent, respectively), subsequent cardiac catheterization (49 percent versus 86 percent), and the timing of catheterization, when performed (30.4 days versus 4.6 days) (p less than 0.005 for all values). Thrombolytic therapy for acute myocardial infarction can be administered quickly, safely, and effectively in rural hospital settings even by physicians previously unfamiliar with this form of treatment.

Cardiac Catheterization↗
PubMed1987

Alterations in left ventricular diastolic function with doxorubicin therapy.

To determine whether impaired diastolic function may be an early sign of doxorubicin cardiotoxicity, a retrospective study was performed in 12 patients who had undergone serial radionuclide angiography and were found to have a left ventricular ejection fraction of 55% or more before doxorubicin (Adriamycin) treatment and during follow-up. Average rapid filling velocity and slow filling velocity were both significantly reduced after doxorubicin treatment. Rapid filling velocity decreased from 5.17 +/- 1.52 to 4.18 +/- 0.96 units/s (p less than 0.01), and slow filling velocity decreased from 2.20 +/- 1.32 to 1.42 +/- 0.62 units/s (p less than 0.05). There were no significant changes in filling volume ratio, total diastolic time or diastolic time ratio. Because a change in left ventricular diastolic function can occur before ejection fraction falls to subnormal levels, diastolic function as well as systolic function should be examined for the early detection of doxorubicin cardiotoxicity. The clinical implications of our observations can only be established by a longer-term prospective analysis of left ventricular function in patients receiving doxorubicin therapy.

Adolescent↗
PubMed1986

The timing of paradoxical wall motion in ventricular aneurysms and in asynergic ventricles.

The timing of paradoxical wall motion was investigated in the left ventricular cineangiograms of 15 patients in whom ventricular aneurysm was diagnosed or excluded at surgery. Eight had aneurysm and 7 had asynergic ventricles without aneurysm. Areas of paradoxical motion and inward motion were planimetered in each quarter of ejection. In both aneurysmal and asynergic ventricles paradoxical motion occurred within large akinetic areas. The extent of paradoxical motion was small, constituting only 3.4 and 2.6% of end-systolic areas. Over 80% of the maximal paradoxical motion occurred in the first half of ejection. In the latter half of ejection, further changes in paradoxical motion were small and inconsistent. There were no significant differences in the extent of quarterly paradoxical wall motion between the two patient groups. These data suggest that in the presence of marked left ventricular asynergy, the extent and timing of paradoxical wall motion from cineangiograms may not be useful in detection ventricular aneurysm.

Cineangiography↗
PubMed1985

[Coronary disease. Medical or surgical treatment?].

Aortocoronary bypass procedures have been proven to be effective in relieving angina pectoris. Whether the procedure actually prolongs life, on the other hand, still remains a matter of controversy. Many prospective and randomized studies have been undertaken in Europe and in the United States on this subject. The results of 6 of these studies are reported and discussed: the Seattle Heart Watch, the Veterans Administration Study, the Cooperative American Study on Unstable Angina, the Cooperative European Study on Coronary Artery Surgery, results of findings from Duke University, and the randomized Coronary Artery Surgery Study. Analysis of results of these prospective studies is of value in establishing a therapeutic approach to coronary artery disease.

Angina, Unstable↗
PubMed1984

Hyponatremia in patients treated with lorcainide, a new antiarrhythmic drug.

The effects of lorcainide, a new antiarrhythmic drug, on serum electrolytes and osmolality are described in a series of 33 patients with organic heart disease and complex ventricular arrhythmias treated with lorcainide. In eight patients, a mean decrease in serum Na+ of 8.25 +/- 3.2 mEq/L was observed after a single 200 mg intravenous dose of lorcainide. Sixteen of 33 patients developed significant hyponatremia and hypoosmolality during oral treatment with lorcainide. In all except two patients, serum Na+ returned to normal values within 3 to 12 months of continued lorcainide therapy. Low serum Na+ and hypoosmolality in the absence of volume depletion, clinically manifest edema, and unaltered renal, adrenal, cardiac, or thyroid function suggest that this antiarrhythmic drug produced the syndrome of inappropriate antidiuretic hormone secretion (SIADH). SIADH appeared to be transient and asymptomatic in our patients. One patient developed severe hyponatremia with serum Na+ of 108 mEq/L when hydrochlorothiazide was given to control hypertension. It is concluded that SIADH is an important side effect of lorcainide therapy. We recommend that serum Na+ be carefully monitored in patients started on lorcainide therapy, and extreme caution should be exercised in prescribing diuretics to patients with persistent hyponatremia.

Adult↗
PubMed1984

Who is normal?

Explore the source record for details and available documents.

Coronary Disease↗
PubMed1984

[Are post-infarction left ventricular aneurysms distensible? Volumetric study using angiography].

During left ventriculography, post-infarction left ventricular aneurysms present as diastolic deformations of the ventricular contour which, when accentuated during systole, give rise to paradoxical systolic expansion. The volumic consequences of thie parietal dyskinesia were studied in 10 cases of chronic anterior wall aneurysm. The borders of the aneurysm were determined by Watson's technique: diastolic and systolic volumes and endocardial surface areas were measured using a computer. In 9 out of 10 cases, neither volume nor endocardial surface area of the aneurysm varied from diastole to systole. Systolic distension of the aneurysm was observed in only one case. In the remainder, paradoxical systolic expansion was related to a charge in the shape of the aneurysm and to overall movement of the heart. The angiographic observations are important for the understanding of the physiopathology of post-infarction aneurysm and for choice of techniques for surgical treatment.

Adult↗
PubMed1983

Subtle left ventricular asynergy with completely obstructed coronary arteries.

The phenomenon of apparently normal angiographic left ventricular wall motion in the presence of greater than or equal to 1 completely obstructed coronary artery was investigated in 16 patients with coronary artery disease (CAD) by quantitative phasic biplane cineangiography. Angiographic contours were digitized at quarterly intervals throughout ejection and 9 areas of motion were measured in both right and left anterior oblique planes. Normal values were derived from 18 other patients who had normal coronary arteries and normal left ventricular function. Areas of asynergy undetected when quantitative analysis was applied only at end-systole in the right anterior oblique plane were found in 12 of the 16 patients with CAD: in 2 patients by end-systolic analysis in the left anterior oblique plane and in 10 patients by phasic analysis of both planes. Of 19 asynergic areas 18 corresponded to sites of high-grade CAD. All patients had angina pectoris, but only 5 had clinical or electrocardiographic evidence of prior infarction.

Cineangiography↗
PubMed1983

Regional sequential motion in the normal left ventricle: nonuniform apical motion.

Timing of the onset and sequence of systolic regional wall motion was examined in the digitized left ventricular cineangiograms of 13 patients with angiographically normal coronary arteries and left ventricular function. Distance--time curves for anterior and inferior wall segments, the aortic valve plane, and apex point were compared to the volume--time curve in each ventricle. No significant differences were found in the onset of motion for the wall segments or for descent of the aortic valve where the sequence of motion was generally uniform. At the apex point, however, the onset of motion was significantly delayed. In addition, reduced velocity of motion in the first half of systole was followed by high velocity motion in the latter half. This apparent nonuniform apical motion may be explained by a geometric relationship of normally contracting myocardial wall fibers adjacent to a thin apical point which has relatively little or no contractile motion of its own.

Cineangiography↗