Showing papers by "Robert Fagard published in 1993"

The relationship between blood pressure and sodium and potassium excretion during the day and at night

Abstract: Objective:The relationships between blood pressure and the urinary excretion rates of sodium and potassium during the day and at night were investigated. Methods: A total of 160 participants (135 normotensive subjects and 25 untreated patients with essential hypertension) were examined using ambulat

Physical fitness and blood pressure.

Abstract: Aim Epidemiological studies suggest an inverse relationship between physical activity or fitness and blood pressure. We therefore performed a meta-analysis of 36 controlled intervention studies. Results The weighted net blood pressure response to dynamic aerobic training averaged -5.3 mmHg for systolic and -4.8 mmHg for diastolic pressure. The interstudy variation in the change in blood pressure was mainly dependent on the initial blood pressure status and the efficacy of the training programme. The weighted net change in blood pressure with endurance training averaged -3/-3 mmHg in normotensives, -6/-7 mmHg in borderline hypertensives and -10/-8 mmHg in hypertensives. Reductions in blood pressure have also been observed for measurements during exercise and during daytime ambulatory monitoring; sleep blood pressure was not, however, significantly altered.

Age and the Hemodynamic Response to Posture and Exercise.

Abstract: The effects of age on hemodynamic variables at rest, in response to orthostatic challenges, and during exercise were assessed from overall weighted statistical summaries of reports in the medical literature. In normotensive subjects at supine rest, cardiac output and stroke volume (p is less than 0.001), but not heart rate, declined with aging, whereas systemic vascular resistance increased (p is less than 0.001). The results were similar in hypertensives, but the slope of the change in cardiac output was steeper than in normotensives (p is less than 0.01). This age-related hemodynamic pattern was also observed in longitudinal follow-up studies. The orthostatic fall in stroke volume and rise in heart rate became less pronounced with increasing age (p is less than 0.05), but the postural increase in systemic vascular resistance was, on average, not related to age. Though the hemodynamic studies in healthy individuals observed that blood pressure is relatively well maintained when older subjects assume the upright position, population studies suggest that an increasing number of these subjects show a postural fall in blood pressure. This is overwhelming evidence that the oxygen uptake at peak exercise decreases with age, mainly related to a lesser peak cardiac output and heart rate (p is less than 0.001).

Cardiac variables and blood pressure as determinants of left ventricular inflow velocities.

Abstract: The determinants of the left ventricular diastolic transmitral flow pattern, measured by use of Doppler velocimetry, were assessed in 40 patients referred for hypertension. The ratio of the atrial to early filling peak velocity (A/E ratio) averaged 0.82 +/- 0.23, BP 156 +/- 19/100 +/- 13 mmHg and left ventricular mass 220 +/- 57. In multiple regression analysis the A/E ratio was independently and positively related to age (P < 0.001) and BP (P < 0.001) and inversely to the fractional shortening of the left ventricular internal diameter (P < 0.01) and left atrial size at end-systole (P < 0.05); these variables accounted for 71% of the variance of the A/E ratio. The peak flow velocity during atrial contraction was positively and independently related to age (P < 0.001), BP (P < 0.05) and heart rate (P < 0.05); early filling velocity decreased with age (P < 0.001) and was positively related to heart rate (P < 0.01), left atrial diameter (P < 0.01) and fractional shortening (P < 0.001). The weak positive associations of the A/E ratio with left ventricular mass (r = 0.32; P < 0.05) and wall thickness (r = 0.38; P < 0.05) did not persist in multiple regression analysis. In conclusion, the left ventricular diastolic filling indexes are related to age, BP, left atrial size and to systolic left ventricular function but left ventricular structural variables, as measured by echocardiography, are not significantly involved.

Influence of Antihypertensive Drugs on Exercise Capacity

Abstract: Both single dose and short term diuretic treatment adversely affect maximal exercise capacity and the duration of prolonged submaximal exercise. However, insufficient data are available to establish the effect of long term diuretic treatment on exercise capacity. β-Blockade reduces maximal aerobic power by approximately 7%. In addition, the capacity for prolonged submaximal exercise appears to be markedly impaired in normotensive and hypertensive patients, particularly when nonselective β-blockers are prescribed. Fewer data are available for other drugs, but, whatever the mechanism of vasodilation, drugs that reduce systemic vascular resistance do not seem to have any effect on exercise capacity.

The older hypertensive. Assessment and treatment.

Abstract: A meta-analysis is presented of 8 therapeutic trials in elderly hypertensive patients. In an intention-to-treat analysis, cardiovascular mortality was decreased on average by 22% (95% confidence interval ranging from -32% to -10%). This decrease was explained by both a reduction in coronary mortality by 26% (-40% to -9%) and in cerebrovascular mortality by 33% (-50% to -9%). The effectiveness of therapy in terms of reducing cardiovascular mortality is not established with confidence in those trials where the diastolic blood pressure at randomization is below 95 mmHg or in the patients above 75 years of age. A goal blood pressure is not definitively established, but a reduction of the systolic blood pressure to about 150 mmHg may be optimal. Extrapolation of the trial results to the elderly population with systolo-diastolic hypertension at large seems acceptable for the western population, but may be premature for the Asian and African elderly. Beta-blockers and especially diuretics are recommended as first-line drugs in elderly patients with symptomless, uncomplicated hypertension, since the effectiveness of other drugs in reducing morbidity and mortality is not yet established. Recommendation for treatment of symptomless patients with isolated systolic hypertension may be premature. The ongoing Syst-Eur and Syst-Chin trials may provide further information.

Does Isradipine Modified Release 5 Mg Once Daily Reduce Blood Pressure for 24 Hours

Abstract: Twelve patients with essential hypertension were randomized in a double-blind cross-over study to investigate the blood pressure BP-lowering activity of isradipine regular formulation (RF) 2.5 mg twice daily (between 7 and 8 a.m. and at approximately 6 p.m.), and isradipine modified release (MR), 5 mg once daily (between 7 and 8 a.m.). The two randomized treatment periods were separated by a placebo period. Patient compliance was similar between placebo and isradipine RF and MR treatment. As compared with placebo, isradipine RF decreased daytime BP by 10 mm Hg systolic (SBP, p < 0.001) and by 6 mm Hg diastolic (DBP, p < 0.01), and night SBP and DBP by 7 (p < 0.05) and 3 mm Hg (P = NS), respectively. Isradipine MR reduced the daytime SBP 8 mm Hg (p < 0.05) and DBP by 3 mm Hg (p = NS), and the night SBP by 1 mm Hg (p = NS) and DBP by < 1 mm Hg (P = NS). Analysis of variance showed that the interaction terms between the effects of treatment and time of day were not significant for SBP (F = 1.56, p = 0.24) or DBP (F = 1.40, p = 0.26) with isradipine RF treatment, but they were significant for SBP (F = 6.33, p = 0.03) and DBP (F = 5.12, p = 0.04) with isradipine MR treatment. Therefore, the BP-lowering effect of isradipine MR 5 mg once daily appears to weaken as the day progresses.(ABSTRACT TRUNCATED AT 250 WORDS)