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Biomedical subjects

J Naughton

Publications and source records attributed to J Naughton.

At least 37 records · Page 2Linked to original sources
PubMed1983

Improved exercise performance following single daily dose of atenolol in stable angina.

We administered atenolol to 10 patients with effort limiting angina pectoris. Doses of 50 mg, 100 mg and 200 mg provided significant improvement (P less than 0.05) in exercise tolerance tested 24 hours after the drug was given. Twenty-five milligrams was not significantly better than placebo in increasing work tolerance. Side effects were minimal, and treatment could be continued throughout the study. The beta-blocker atenolol is an effective drug in the treatment of exercise-induced angina.

Adult↗
PubMed1983

Future possibilities for conducting clinical trials to test the efficacy of beta-blocker medications.

Beta-blocker therapy apparently is important in the short- and long-term care of patients with myocardial infarction (MI). In the former, administration may reduce MI size, and in the latter, it promotes a statistically significant reduction in mortality. Since beta blockers exert a number of effects, it is still not known how the specific beneficial effects are mediated. Nevertheless, there is still a need to examine the effects of beta blockers, either singly or combined with other medications, on patients recovering from acute MI and as a late intervention. Specific attention must be directed to the older patient, those with moderate myocardial dysfunction, and those with life-threatening ventricular dysrhythmias. Each of these problems must be addressed by a well-designed, randomized clinical trial to ensure the best possible study design and the most accurate scientific outcome.

Adrenergic beta-Antagonists↗
PubMed1982

Effect of long-term moderate physical exercise on plasma lipoproteins. The National Exercise and Heart Disease Project.

As part of the National Exercise and Heart Disease Project, 223 postcoronary men, aged 30 to 64, were randomly assigned to moderate exercise or control groups. Levels of total plasma cholesterol, high- and low-density lipoprotein (HDL and LDL) cholesterol, and triglycerides were measured. At baseline, alcohol intake, weight, and skin-fold thickness but not treadmill work capacity correlated with triglyceride or HDL cholesterol levels. After one year, no clinically important change in lipid levels was observed in either group. Using multiple regression analysis of the combined groups, changes in several independent variables, including work capacity change, were not predictive of changes in lipid levels. Thus, changes in levels of fitness and/or regular exercise did not substantially influence HDL cholesterol or other lipid levels.

Adult↗
PubMed1978

The National Exercise and Heart Disease Project. The pre-randomization exercise program. Report number 2.

The National Exercise and Heart Disease Project (NEHDP) was funded by the Rehabilitation Services Administration (RSA) of the Department of Health, Education and Welfare, to determine the effects of regular physical activity on the rehabilitation, morbidity and mortality of patients with healed myocardial infarctions. Planning and development lasted from June 1972 through September 1974. Since 1974, 932 subjects were referred for evaluation. At randomization, 651 subjects were assigned to exercise treatment (323) or control (328) groups. Those who qualified for randomization had to complete an initial evaluation, attend 14 of 18 consecutively scheduled, low-level physical activity sessions during a period of 6 weeks, and complete a second evaluation. This prerandomization phase was accompanied by significant alterations in work capacity, heart rate levels at rest and during three levels of physical stress, systolic blood pressure reductions during stress but not at rest, and by changes in the level of anxiety and depression. The subjects will be followed for a minimum of 2 years at regular intervals to determine if regularly performed physical activity is beneficial to the rehabilitation of myocardial infarction survivors.

Adult↗
PubMed1976

Isosorbide dinitrate and cardiovascular adaptation to exercise.

Sixteen men with well-documented angina pectoris and without previous myocardial infarction performed a multistage exercise stress test to determine their levels of exercise-induced limitations, characterized by onset of chest discomfort or electrocardiographic ischemic changes, or both. Following a control study, each subject was assigned randomly to either a placebo- or vasodilator-treated group, received chewable medication, and was retested 30 minutes after chewing the medication. Blood pressure, heart rate, and electrocardiographic changes were measured during rest, peak exercise, and recovery. A phonocardiogram, carotid-pulse contour, and single-lead electrocardiogram were recorded simultaneously at supine rest before and immediately after exercise, and systolic time intervals were measured. Results indicated that chewable isosorbide dinitrate reduced systolic blood pressure and the triple product (systolic blood pressure X heart rate X ejection time) significantly during rest and reduced the left ventricular ejection time corrected for heart rate both at rest and peak exercise; no significant differences were observed in the placebo group. The ability to achieve an increased workload was observed in both groups, and the threshold for ischemic manifestations occurred at comparable triple-product levels in both during pretreatment and posttreatment studies.

Adaptation, Physiological↗
PubMed1976

Effect of exercise on left ventricular ejection time in patients with prolapsing mitral leaflet syndrome.

The effect of exercise on left ventricular ejection time was determined in 12 subjects with prolapsing mitral valve leaflet syndrome (PML). A single lead ECG (CM5), phonocardiogram and carotid pulse contour were recorded simultaneously with the subjects at supine rest before and immediately after multistage treadmill exercise. Systolic time intervals were measured from five consecutive complexes to determine the pre-ejection period (PEP), left ventricular ejection time (LVET) and total electromechanical systole (QS2). LVET was corrected for heart rate and defines as LVETc. In nine subjects, an increase of 1 to 49 msec was observed in the LVETc following exercise. A shorter resting LVETc and greater afterload at peak exercise was related to an increase in LVETc of 10 msec or more. Exercise elicited or evoked evidence of left ventricular dysfunction. The results support the concept that impaired left ventricular performance is a concomitant of this syndrome.

Adult↗