PubMed Health⌕ Search

Biomedical subjects

B Hatfield

Publications and source records attributed to B Hatfield.

11 recordsLinked to original sources
PubMed1999

Aerobic exercise attenuates blood pressure reactivity to cold pressor test in normotensive, young adult African-American women.

Exaggerated blood pressure reactivity to behavioral stress has been observed in the African-American population, and such a pressor response is believed to play a role in hypertension. Regular aerobic exercise has been shown to exert an anti-hypertensive effect, and this may alter the blood pressure hyperreactivity observed in African Americans. To test the hypothesis that aerobic exercise attenuates pressor reactivity in African Americans, we studied eight healthy aerobically-trained normotensive African-American females and five similar sedentary females. The stress stimuli consisted of the cold pressor test with the foot immersed in ice water for two minutes. The aerobic exercise training protocol consisted of six weeks of jogging at 60-70% of peak oxygen uptake (VO2peak), three days/week for 35 min/exercise session. Systolic blood pressure, diastolic blood pressure, mean arterial blood pressure, heart rate, cardiac output, total peripheral resistance, and forearm blood flow were measured. Manifestation of a training effect was illustrated by a 24.1 +/- 0.2% increase in VO2peak (26.9 +/- 1.2 mL x kg(-1) min(-1) vs 35.4 +/- 1.6 mL x kg(-1) min(-1)) (P<.05). Within the exercise-trained group there was a 6.3 +/- .15% decrease in systolic pressure (129 +/- 4.6 mm Hg vs. 121 +/- 5.4 mm Hg) (P<.05), and a 5.0 +/- .05% decrement in mean arterial blood pressure (99 +/- 3.3 mm Hg vs 94 +/- 3.6 mm Hg) (P<.05) during the cold pressor test. Pressor reactivity to cold stress did not change in the untrained group. Measures of heart rate, cardiac output, total peripheral resistance, and forearm blood flow were unaltered during conditions of the cold pressor test. We conclude that aerobic exercise attenuates the blood pressure reactivity to behavioral stress in young, adult normotensive African-American females. A lifestyle change such as exercising may play a role in reducing the risk of hypertension in African-American women.

Adult↗
PubMed1996

Staff looking after children in local authority residential units: the interface with child mental health professionals

Seventy-two members of staff working in children's residential units in a Local Authority were surveyed, to elicit their experiences and evaluations of working with child mental health professionals. Whilst the majority of staff held few or no formal educational qualifications, they emerged as an experienced group, with a level of confidence in their knowledge and skill base. Support was identified as coming predominantly from within units themselves; relatively few staff had direct contact with child psychiatrists or psychologists, although many children received a service. Staff in general felt that child mental health services were not helpful to them in terms of their work with young people. However, the majority of staff indicated a need for greater direct involvement across a range of child behavioural and emotional problems. The findings are discussed in terms of the changing population of "looked after" children and the recommendations of the Warner Report.

Journal Article↗
PubMed1995

Hemodynamic and energetic comparison of bucindolol and metoprolol for the treatment of congestive heart failure.

Although beta blockers have demonstrated a salutary effect on ventricular function in patients with heart failure, it is unclear whether a nonselective third-generation beta blocker produces different hemodynamic and energetic effects than a second-generation beta 1 selective agent. In 30 male patients with heart failure, we retrospectively analyzed hemodynamic data from 2 protocols examining the effects of a nonselective beta antagonist bucindolol (n = 15), and a highly selective beta 1 antagonist metoprolol (n = 15). Both studies were conducted in a similar fashion with patients undergoing cardiac catheterization before and after receiving 3 months of beta blockade. Both groups were matched at baseline in terms of ventricular function. beta blockade resulted in similar reductions in heart rate and similar improvements in ejection fraction, ventricular volumes, stroke and minute work, peak +dP/dt, and isovolumic relaxation in both groups. Only patients taking bucindolol had a significant within-group decrease in resting left ventricular end-diastolic pressure. The metoprolol group had a greater decrease in coronary sinus blood flow and myocardial oxygen consumption. Bucindolol increased cardiac index more than metoprolol, but did not increase stroke volume index more than metoprolol. The bucindolol group had an increase in systolic elastance, whereas the metoprolol group had a parallel left shift in this relation. Thus, metoprolol reduces coronary blood flow and myocardial oxygen consumption more than bucindolol, whereas bucindolol produces slightly more favorable improvements in resting cardiac index and end-diastolic pressure. Otherwise, these 2 agents produced similar hemodynamic changes.

Adrenergic beta-Antagonists↗
PubMed1995

Predictors of systolic and diastolic improvement in patients with dilated cardiomyopathy treated with metoprolol.

OBJECTIVES: The aim of this study was to determine which patients will have systolic and diastolic improvement after beta-blockade with metoprolol. BACKGROUND: Beta-adrenergic blocking agents improve systolic and diastolic function in patients with heart failure. However, it is unclear which patients will respond best to therapy. METHODS: We retrospectively examined baseline characteristics of 24 patients who underwent double-blind then open-label treatment with metoprolol to determine which characteristic predicted improvement in systolic and diastolic function. Degree of improvement in systolic function (22 patients) was defined by the change in left ventricular ejection fraction after 3 months of therapy. Degree of improvement in diastolic function (15 patients) was defined as the change in left ventricular end-diastolic pressure and change in the slope of the isovolumetric relaxation rate-end-systolic pressure relation. RESULTS: Both systolic blood pressure at baseline (r = 0.54, p = 0.009) and the maximal positive value of the first derivative of left ventricular pressure with respect to time (peak +dP/dt) at baseline (r = 0.39, p = 0.07) correlated with improvement in ejection fraction after metoprolol treatment. Stepwise logistic regression demonstrated that only peak systolic pressure was an independent predictor of systolic improvement. Baseline heart rate, ventricular volumes, ejection fraction and adrenergic activation, as reflected by coronary sinus norepinephrine, did not predict response. Patients with the most diastolic impairment at baseline had the most favorable diastolic improvement. Those with the lowest myocardial respiratory quotient (most fatty acid utilization) at baseline also had the most marked reduction in left ventricular end-diastolic pressure. CONCLUSIONS: These data suggest that those patients with the highest peak systolic pressure, highest left ventricular end-diastolic pressure and most prolonged isovolumetric relaxation at baseline will respond best to therapy with metoprolol. However, other patients without these characteristics may also benefit.

Adult↗
PubMed1994

Functional importance of myocardial relaxation in patients with congestive heart failure.

The factors that determine left ventricular end-diastolic pressure (LVEDP) are not completely understood. While many investigators measure relaxation in patients with heart failure, its relative functional importance remains unclear. The authors studied 22 patients with cardiomyopathy before and after 3 months of therapy with metoprolol or placebo. At catheterization, LVEDP, isovolumic relaxation rates not normalized for load (tau), the slope of the tau-end-systolic pressure relation (R), the constant of chamber stiffness (k), left ventricular ejection fraction, stroke volume, and coronary sinus norepinephrine levels were measured using micromanometer pressure measurements and digital ventriculography. The myocardial respiratory quotient was measured using blood gas analysis of the coronary sinus and left ventricular blood. Univariate analysis demonstrated that changes in LVEDP correlated with changes in relaxation rates, R, and the myocardial respiratory quotient. However, multivariate stepwise regression analysis demonstrated that only changes in R independently correlated with changes in LVEDP. These data suggest that relaxation may play some role in the determination of LVEDP in patients with heart failure. Changes in glycolytic activity may also play a role in the determination of LVEDP in patients with congestive heart failure.

Adult↗
PubMed1992

The 1983 Mental Health Act in five local authorities: a study of the practice of approved social workers.

This paper represents the first report of an ongoing collaborative project and charts the activities of social workers undertaking their duties within the framework of the 1983 Mental Health Act in five English Local Authorities for one year. Social workers are involved in a range of duties under the Act, but most commonly they are involved in assessments with a view to compulsory detention. The characteristics of people assessed are examined, and a profile emerges of vulnerable subgroups, typically younger men, older women, and people living in socially impoverished situations. Considerable variation between Authorities is found in terms of numbers of assessments, and in numbers of detentions. Low levels of 'diversion' into alternative care are identified. Comparisons are made with a major national study which took place four years earlier. Higher rates of detention are found on average, but lower rates of use of emergency provision (Section 4). An examination of the organisational context within which Approved Social Workers (ASWs) practice reveals a great deal of variation between authorities in terms of the ongoing experience of assessments available to ASWs. Social workers based in Emergency Duty Teams and Hospital Teams are compared, and a distinctive profile of their work emerges, the hospital-based ASWs being more likely to be assessing 'known' people, often already in hospital, and referred for assessment by consultants. The implications of these findings for the management and deployment of Approved Social Workers are briefly discussed. The emphasis is upon the role of the ASW in terms of balancing the rights and needs of people assessed under the Act.

Adult↗