Ambulatory blood pressure monitoring: a question for now and the future.
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Antihypertensive Agents↗
Biomedical subjects
B N Garrett
Publications and source records attributed to B N Garrett.
Postmarketing survey of the effects of an atenolol/chlorthalidone combination in the treatment of hypertension.
A large-scale postmarketing survey was conducted in the United States to evaluate the antihypertensive efficacy and safety of a combination of 50 mg of the long-acting cardioselective beta-blocker atenolol and 25 mg of the monosulfonamyl diuretic chlorthalidone. The program included 28,585 patients (of whom 26,892 provided sufficient information by questionnaire for an assessment of efficacy and race), and the participation of 7,009 primary-care physicians. After four weeks of treatment, patients had a mean reduction in systolic blood pressure of 21 mmHg and in diastolic blood pressure of 13 mmHg. The magnitude of these reductions did not differ appreciably with respect to age, sex, race, or previous therapy. Diastolic blood pressure was reduced by at least 11 mmHg in 55% of patients and systolic blood pressure was reduced by at least 16 mmHg in 59% of patients. Physicians' assessments indicated that 86% of patients achieved satisfactory control of blood pressure by the end of the study. The physicians' global assessment of the effectiveness of treatment indicated that the combination was better than previous therapy in 82% of patients; 91% of physicians planned to continue treatment with the fixed combination. There were no adverse experiences that had not been reported previously, and only dizziness exceeded an incidence of 1%. It was concluded that the fixed combination provides added blood pressure control and the convenience of a simplified once-daily regimen without added side effects, regardless of age, sex, race, or prior antihypertensive therapy.
Adolescent↗
The role of ambulatory blood pressure monitoring in the evaluation of adolescent hypertension.
We performed 24-hour ambulatory blood pressure monitoring in a group of adolescents with hypertension induced by dynamic exercise and a group of normotensive controls. Ambulatory blood pressure monitoring was performed using a Del-Mar Avionics PIII recorder with readings taken every 7 1/2 minutes. There was little inter-individual variation in mean hourly blood pressure and the difference between mean hourly readings was not significant in hypertensives. Mean 24-hour ambulatory blood pressure was 130.2/80.7 mmHg for hypertensives and 115.2/70.8 in normotensives. Mean 24-hour variability was 18.3/12.9 mmHg in hypertensives and 14.6/11.5 in normotensives. There was no significant change in blood pressure or variability between day-time and evening for hypertensives. Normotensives showed a significant reduction in both BP and variability compared to hypertensives. In adolescents with systolic hypertension, ambulatory blood pressure monitoring confirmed a failure to reduce blood pressure following routine activity. This technique maybe used as a predictive marker of early, adult essential hypertension.
Adolescent↗
Acute aortic dissection.
Acute aortic dissection is the most lethal complication affecting the aorta. The use of two-dimensional echocardiography and computed tomography has greatly expanded the physician's ability to establish this diagnosis through noninvasive techniques. Surgery is the definitive treatment for type I and II dissection, whereas medical management with drugs that reduce cardiac output remains the treatment of choice in type III dissection. With improvements in surgical techniques, including cardiopulmonary bypass and composite grafting, immediate and long-term morbidity and mortality have been significantly reduced.
Aortic Dissection↗
Effect of pindolol on potassium homeostasis in patients with essential hypertension.
A study of the effects of pindolol on potassium homeostasis was undertaken in 25 patients (19 women, 6 men) with essential hypertension. The patients were maintained on their usual diet and were withdrawn from antihypertensive therapy for three weeks before the study began. They were then randomly assigned to one of three treatment groups: (a) pindolol, 15 mg daily; (b) hydrochlorothiazide, 50 mg daily; and (c) both drugs combined. Total body potassium (TBK), urine aldosterone excretion, and plasma renin activity (PRA) were measured after eight weeks of therapy and compared with pretreatment values. Mean PRA remained unchanged in patients taking only pindolol or the drug combination, but it rose significantly in patients taking only hydrochlorothiazide. Mean urine aldosterone concentrations fell in patients taking only pindolol, rose in those taking only hydrochlorothiazide, and remained unchanged in those taking the combination. Mean TBK concentrations rose significantly in patients taking only pindolol or the combination, and fell significantly in those taking only hydrochlorothiazide. The rise in TBK concentrations with the combination clearly suggests that pindolol offsets the potassium wastage induced by diuretics, though probably by a mechanism outside the renin-aldosterone system. Because of this rise, it may be possible to eliminate potassium supplementation in patients taking the combination pindolol and hydrochlorothiazide.
Adult↗
Efficacy of slow infusion of diazoxide in the treatment of severe hypertension without organ hypoperfusion.
Diazoxide, as usually given in a single bolus, may cause precipitous falls in blood pressure (BP) with resultant tissue hypoperfusion. To examine the efficacy and safety of slow infusion, we treated 18 patients with mean initial BP of 220/143 mm Hg by two regimens: group A (nine patients) received 15 mg/minute; group B (nine patients) received 30 mg/minute. The goal of therapy, diastolic BP of 100 to 105 mm Hg, was reached in 16 of the 18 with no immediate drug-related side effects. Infusion time was 38.1 minutes in group A and 20.7 minutes in group B. Slow intravenous infusion of diazoxide appears to be safe and effective treatment for severe hypertension and should replace the rapid bolus technique.
Adult↗
Lofexidine in the treatment of hypertension: a twice-daily versus one-daily dose comparison with 24-hour blood pressure monitoring.
Lofexidine, an antihypertensive imidazoline derivative, was given to ten hypertensives on both a twice-daily and once-daily regimen, using routine blood pressure measurements and 24-hour Remler recording. Plasma renin activity and catecholamines were measured. After a dose titration with twice-daily doses, the total twice-daily dose was given once daily for two weeks and the drug abruptly withdrawn. Mean placebo blood pressure was 136/104 mm Hg supine. After twice-daily therapy, this fell to 118/86 mm Hg, and upon conversion to once-daily therapy, it rose to 126/89 mm Hg. With the Remler recorder, mean 24-hour blood pressure was 125/89 during the twice-daily therapy, 133/94 mm Hg during once-daily therapy, and 142/99 mm Hg on the day after acute withdrawal; i.e., evaluation in all three treatment periods showed a lack of sustained control with both a wide range and high frequency of blood pressure variation. Plasma renin activity and plasma epinephrine and norepinephrine did not change significantly during the study.
Adult↗
Moderate sodium restriction and various diuretics in the treatment of hypertension.
Changes in total body potassium level and blood pressure (BP) were determined in multiple studies on 12 hypertensive subjects ingesting a diet either moderately restricted or higher in sodium. On both diets, the following diuretics were randomly given for four-week intervals: chlorthalidone, hydrochlorothiazide, or furosemide. Total body exchangeable potassium level fell 225 mEq with lower sodium intake and 455 mEq with higher intake, combining all diuretics. Chlorthalidone caused more potassium wastage than the other diuretics. The average falls in mean BP were 13.9 mm Hg with the lower sodium diet and 9.1 with the higher sodium diet, combinging all diuretics. Combining both diets, chlorthalidone produced the greatest fall and furosemide produced the slightest. These data suggest that if a diuretic is used to treat hypertension, a diet moderately restricted in sodium and a single morning dose of a diuretic of intermediate duration of action offer the best balance of efficacy and safety for most patient.
Adult↗
Plasma renin activity suppression: duration after withdrawal from beta-adrenergic blockade.
beta-Blocking drugs suppress plasma renin activity (PRA) promptly. The current study was undertaken to document the return of PRA once blockade is withdrawn. In addition, we have correlated the return of PRA with both fall in plasma propranolol levels and change in blood pressure (BP). Fourteen patients established a baseline PRA. Propranolol hydrochloriode, 40 mg twice daily, was given for seven days and withdrawn abruptly. The PRA, plasma propranolol level, and BP were measured one and 12 hours after withdrawal, then every 24 hours. The PRA returns to baseline 12 hours after cessation of therapy. After withdrawal of therapy, there seems to be a "rebound" phenomenon in PRA, with elevations of 70% above baseline. This rebound also is demonstrated by a nonsignificant rise in BP. Plasma propranolol levels fall by; 70% within 13 hours of withdrawal. The decrease in propranolol levels closely correlates with the rise in PRA.
Adrenergic beta-Antagonists↗
Metoprolol in diabetes mellitus: effect on glucose homeostasis.
1. In eight hypertensive diabetic subjects receiving hydrochlorothiazide, glucose homeostasis as measured by the changes in plasma glucose, insulin and glucagon after an oral glucose load was not significantly affected by 8 weeks of therapy with metoprolol. 2. The combination of metoprolol plus hydrochlorothiazide significantly lowered blood pressure in all subjects. 3. Plasma renin activity was suppressed by therapy with metoprolol.
Aged↗
Clonidine in the treatment of hypertension.
Clonidine has clearly been shown to be effective in the treatment of all grades of hypertension. Clonidine by itself, when compared with placebo, has proved its worth in the treatment of essential hypertension; it has also been found to be more effective than diuretic treatment alone. When clonidine and a diuretic have been combined, the combination has proved superior to either clonidine or the diuretic given alone. The combination of clonidine with a diuretic is equal in efficacy to combinations of a diuretic with a beta-blocker, alpha-methyldopa, or prazosin. Combinations of a diuretic, a vasodilator, and clonidine were useful in patients with refractory hypertension that failed to respond to a two-drug regimen. Clonidine has also been shown to be effective in patients with renal failure or in hypertensive crisis.
Adolescent↗