Is there a relationship between ambulatory intra-arterial blood pressure and left ventricular function?

The relationship between ambulatory intra-arterial blood pressure and left ventricular ejection fraction was examined in a group of 23 untreated hypertensive subjects who underwent concurrent radionuclide ventriculography. All patients had a normal ejection fraction at rest (range, 50-80%), and no significant correlation was found between blood pressure and resting ejection fraction. Sixty-one percent of patients failed to increase their ejection fraction by 5% on exercise; the mean daytime systolic pressure (168 +/- 15 mm Hg) was lower in this group than in those who had a normal exercise response (188 +/- 17 mm Hg; p less than 0.005). Thirty percent of patients had left ventricular hypertrophy based on electrocardiographic criteria; this group had a higher mean blood pressure (189 +/- 20 mm Hg) than the remainder (170 +/- 15 mm Hg; p less than 0.05). A closer correlation was demonstrated between blood pressure and ejection fraction response to exercise in the group with left ventricular hypertrophy (r = 0.8) than in the group without hypertrophy (r = 0.3). These results failed to demonstrate a linear relationship between blood pressure and ejection fraction. However, a relationship between the height of blood pressure and the development of left ventricular hypertrophy was shown, and myocardial response to exercise was increased in patients with left ventricular hypertrophy.

Carvedilol for systemic hypertension.

Twenty-four-hour profiles of intraarterial ambulatory blood pressure (BP) and heart rate were significantly reduced by administration of carvedilol, a new beta-blocking drug with vasodilating properties. Twelve patients were given carvedilol, 25 mg twice daily for 2 weeks; the dose was then increased to 50 mg twice daily if the target BP was not achieved. After 4 weeks of therapy, mean daytime reduction in BP was 25 +/- 3 mm Hg systolic and 19 +/- 3 mm Hg diastolic and mean reduction in heart rate was 22 +/- 3 beats/min. BP at the peak of isometric exercise and during dynamic exercise was also significantly reduced. Radionuclide measurements showed that left ventricular ejection fraction was not affected by treatment, but there was a significant reduction in systolic and diastolic volumes. The drug was well tolerated. This clinical trial suggests that carvedilol will be a useful first-line drug for treatment of essential hypertension, and its vasodilating action may have a more favorable effect on left ventricular function than conventional beta-blocking drugs.

First dose response and 24-hour antihypertensive efficacy of the new once-daily angiotensin converting enzyme inhibitor, ramipril.

The reduction in blood pressure (BP) after the first dose and after 8 weeks of treatment with a new once-daily angiotensin converting enzyme (ACE) inhibitor, ramipril, was examined in 12 untreated hypertensive patients, using ambulatory intraarterial BP monitoring. The first period of monitoring began 24 hours before the first dose was given, and continued for 24 hours afterwards. A second 24-hour period of monitoring was carried out after 8 weeks of treatment, commencing immediately after the morning dose. Angiotensin II levels and serum drug levels were measured at 0, 2, 6 and 24 hours after the acute dose. BP decreased progressively from the first hour after the first dose, reached a maximum in the fifth hour (p less than 0.001) and then the effect diminished. The maximum reduction of systolic BP in any patient was 64 mm Hg, the minimum 4 mm Hg. Blood pressure was significantly (p less than 0.05) reduced throughout the 24 hours after dosing, with a mean daytime reduction of 13/12 mm Hg, and a mean nighttime reduction of 15/7 mm Hg. Angiotensin II levels were significantly (p less than 0.02) and maximally reduced by 2 hours after administration, but the reduction was no longer significant after 24 hours. Serum drug levels were also maximal 2 hours after administration. The trial population could be clearly divided into groups of good and poor responders on the basis of BP reduction. The angiotensin II levels were higher before treatment, and decreased further, in all patients with a good response than in those with a poor response.(ABSTRACT TRUNCATED AT 250 WORDS)

Effectiveness of the once-daily calcium antagonist, lacidipine, in controlling 24-hour ambulatory blood pressure.

The efficacy of the new once-daily dihydropyridine calcium antagonist, lacidipine, in reducing ambulatory intraarterial blood pressure (BP) was examined in 12 untreated hypertensive patients. The intraarterial recording was commenced 24 hours before the first 4-mg dose and was continued for a further 24 hours thereafter. After dose titration and chronic therapy, a second 24-hour ambulatory BP recording was made. There was a steady onset of drug action, maximal at 2 hours, but with reflex tachycardia after the first dose. Chronic administration reduced BP throughout the 24-hour period, without tachycardia. Mean daytime reduction in BP was 20 mm Hg systolic (p less than 0.005) and 12 mm Hg diastolic (p less than 0.02). Mean nighttime reduction was 8-mm Hg systolic (p less than 0.05) and 6-mm Hg diastolic (difference not significant). There was no postural decrease in BP on 60 degrees head-up tilting and hypotensive action was maintained during isometric exercise (reduction at peak of 32/18 mm Hg, p less than 0.05) and throughout dynamic exercise (reduction at peak of 23/14 mm Hg, p less than 0.05). Lacidipine is an effective once-daily antihypertensive agent, with good control of stress response.

Safety and pharmacokinetics of ioversol in healthy volunteers.

Ioversol 320, a new nonionic iodinated contrast medium, was injected intravenously into 24 healthy male volunteers using saline as a control. Physical examination, vital signs, electrocardiogram, biochemical and hematological data were recorded before and at intervals after injection. No significant changes were observed. Seventeen volunteers reported no side effects; six volunteers had mild transitory symptoms considered to be related to the contrast medium. The authors conclude that broader clinical trials can be safely conducted to determine safety and tolerability of ioversol.

Carvedilol for systemic hypertension.

Twenty-four hour profiles of intraarterial ambulatory blood pressure (BP) and heart rate were significantly reduced by administration of carvedilol, a new beta-blocker with vasodilating properties. Twelve patients were given carvedilol, 25 mg twice daily for 2 weeks; the dose was then increased to 50 mg twice daily if the target BP was not achieved. After 4 weeks of therapy, mean daytime reduction in BP was 25 +/- 3 mm Hg systolic and 19 +/- 3 mm Hg diastolic, and mean reduction in heart rate was 22 +/- 3 beats/min. BP at the peak of isometric exercise and during dynamic exercise was also significantly reduced. Radionuclide measurements showed that left ventricular ejection fraction was not affected by treatment, but there was a significant reduction in systolic and diastolic volumes. The drug was well tolerated. This clinical trial suggests that carvedilol will be a useful first-line drug for treatment of essential hypertension, and its vasodilating action may have a more favorable effect on left ventricular function than conventional beta-blocking drugs.

Blood pressure changes during the game of squash.

The extent and pattern of the blood pressure response to the playing of squash was studied in five healthy volunteers using intra-arterial blood pressure recordings. Systolic pressure increased more than diastolic, but by only 18% of basal, peaking 5.2 +/- 2.3 min into the game (mean game duration 49 +/- 4 min). Thereafter there was a progressive decline, with reducing pulse pressure towards basal. There was a marked and significant increase in beat-by-beat blood pressure variability (P less than 0.01) and systolic peaks of up to 200 mmHg were recorded. A peak heart rate of 171 +/- 25 beats min-1 occurred at 20 min. These findings do not support the concept of a disproportionate and prolonged pressor response induced by playing squash. The possibility of high single-beat systolic peaks still justifies some caution in subjects at risk of arterial rupture.