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Biomedical subjects

P Omvik

Publications and source records attributed to P Omvik.

At least 55 records · Page 3Linked to original sources
PubMed1993

Modest antihypertensive effect of epanolol, a beta 1-selective receptor blocker with beta 1 agonist activity: an acute and long-term hemodynamic study at rest and during exercise and double crossover comparison with atenolol on ambulatory blood pressure.

Beta-blockers with less cardiodepressive effect than traditional nonselective beta(1+2)-blocking agents could be useful in the treatment of hypertension, provided the reduction in blood pressure was satisfactory. Epanolol, a selective beta 1-receptor blocker with intrinsic sympathomimetic activity, induced a fall in intraarterial pressure of 8% at rest sitting and 11% during 100 W bicycle exercise after the first dose of 200 mg in 12 patients with essential hypertension. Heart rate, stroke index, and cardiac index initially fell by 14%, 11%, and 23%, respectively. The total peripheral resistance index increased by 21% after 2 hours, and then reverted towards the pretreatment level. After 10 months of epanolol treatment (mean 300 mg/day), the reduction in arterial pressure was 5% at rest and 10% during exercise. Cardiac index and heart rate were still reduced 14-21%, while total peripheral resistance was unchanged or slightly increased (2-10%). Twenty-four hour ambulatory blood pressure was higher on epanolol (300 mg/day) than on atenolol (150 mg/day) treatment (137/97 vs. 128/91 mmHg). Thus, the achieved blood pressure reduction induced by epanolol was moderate, while other characteristics of beta-receptor blockade, in particular, the reduction of heart rate and cardiac output, were maintained. This suggests that the compound may be useful for other cardiovascular disorders, e.g., angina pectoris in patients without hypertension or cardiac arrhythmia.

Adrenergic beta-Agonists↗
PubMed1993

Long-term hemodynamic effects at rest and during exercise of newer antihypertensive agents and salt restriction in essential hypertension: review of epanolol, doxazosin, amlodipine, felodipine, diltiazem, lisinopril, dilevalol, carvedilol, and ketanserin.

Hypertension is due to disturbance of the complex interplay between numerous known and unknown mechanisms that normally control blood pressure. Antihypertensive agents may, therefore, reduce blood pressure through widely different actions and, at the same time, elicit counterregulatory responses. This is a review of the long-term hemodynamic effects at rest as well as during exercise of nine relatively new antihypertensive compounds: a beta-blocker (epanolol), an alpha-receptor blocker (doxazosin), two double-acting compounds (dilevalol and carvedilol), three calcium antagonists (amlodipine, felodipine, and diltiazem), an angiotensin-converting enzyme inhibitor (lisinopril), a serotonin antagonist (ketanserin), and low-salt diet as a nonpharmacological treatment in 171 patients with mild to moderate essential hypertension. The results in the treatment groups are compared to the hemodynamic changes seen in 28 hypertensive patients left untreated for 10 years. The patient populations of the different groups were comparable. The invasive hemodynamic technique, including intraarterial blood pressure recording and measurements of cardiac output by Cardigreen, was the same in all studies. While blood pressure remained nearly unchanged in the untreated group, all antihypertensive compounds induced significant and sustained blood pressure reduction both at rest and during exercise. The modest reduction (3-5%) in blood pressure during a low-salt diet was also statistically significant. This review shows the multiplicity of the long-term hemodynamic changes, ranging from a reduction in cardiac output to peripheral vasodilatation, during chronic antihypertensive therapy. In untreated hypertensives, the cardiac output is reduced by 1-2% per year and total peripheral resistance is increased by 2-3% per year. The review also focuses on counterregulatory responses and modify the initial reduction in blood pressure after drug treatment for hypertension. It is concluded that proper understanding of the hemodynamic effects of antihypertensive agents is useful in the selection of the right treatment for specific groups of hypertensive patients.

Adult↗
PubMed1993

Double-blind, parallel, comparative study on quality of life during treatment with amlodipine or enalapril in mild or moderate hypertensive patients: a multicentre study.

OBJECTIVE: To compare tolerance, antihypertensive efficacy and impact on quality of life of amlodipine and enalapril in patients with mild or moderate hypertension. DESIGN: Multicentre, double-blind, double-dummy, comparative trial in general practice. Three phases were conducted: 4 weeks on placebo, 12 weeks of dose adjustment (amlodipine or enalapril) and a 38-week maintenance period. PATIENTS: Four hundred and sixty-one patients of both sexes were enrolled; 451 were available for efficacy evaluation at the end of the trial. TREATMENT: The patients were allocated to either amlodipine (231) or enalapril (230) treatment. If at the end of dose adjustment (amlodipine 5-10 mg/day, enalapril 10-40 mg/day) diastolic blood pressure was > or = 95 mmHg, hydrochlorothiazide (25-50 mg/day) was added (27 amlodipine patients and 45 enalapril patients). MAIN OUTCOME MEASURES: Blood pressure changes after 1 year of treatment; between- and within-group changes in quality of life as assessed by psychological general well-being, social and sexual functioning, health-risk perception, alertness, behaviour, and impact of symptom and side effects. RESULTS: Indices on quality of life were unchanged or increased (2-9%) in both groups. Blood pressure was normalized or reduced by > or = 10 mmHg in 204 (90%) and 190 (85%) patients on amlodipine and enalapril, respectively. Cough was the most frequently reported adverse event in the enalapril group (13%) and oedema in the amlodipine group (22%). Only eight (4%) patients on amlodipine and nine (4%) on enalapril were withdrawn because of drug-related adverse events. CONCLUSION: At similar blood pressure reduction in mild and moderate hypertension, quality of life is equally well maintained on amlodipine and enalapril therapy.

Adaptation, Psychological↗
PubMed1993

The Bergen blood pressure study: sodium intake and ambulatory blood pressure in offspring of hypertensive and normotensive families.

Sodium intake, estimated by the 24-h urine sodium excretion, was assessed in 39 offspring of hypertensive families and 37 offspring of normotensive families. The family history of hypertension or normotension was defined according to parental BP data from two surveys conducted 27 years apart. Urine-sodium excretion was similar in offspring of hypertensive and normotensive families, averaging 136 and 137 mmol/24 h, respectively. Monitored by non-invasive methodology in the urine sampling period, the average 24-h ambulatory blood pressure (BP) was approximately 10/10 mmHg higher in offspring of hypertensive than normotensive families. The clinically and statistically significant differences in BP between groups could not be explained by differences in sodium intake. After adjustment for confounding variables, the BP was not associated with the sodium excretion in the material as a whole or in either offspring group.

Adult↗
PubMed1993

The Bergen Blood Pressure Study: blood pressure changes, target organ damage and mortality in subjects with high and low blood pressure over 27 years.

Based on the Bergen population screening in 1963-64, 344 married couples (688 subjects), then aged 30-69 years, were included for studies in families with a history of hypertension or normotension. In 1990 430 subjects were available to a follow-up examination. The present paper describes 27-year mortality, blood pressure (BP) changes, cardiovascular disease and target organ damage in this population. In males who were hypertensive by the 1963-64 screening BP, the all-cause 27-year mortality was three times higher than in initially normotensive males (p < 0.05). From 1963-64 to 1990, the systolic BP was generally increased, whereas the diastolic BP was decreased in initially hypertensive and increased in initially normotensive subjects. In subjects who were hypertensive in 1963-64, the relative risk of hypertension in 1990 was more than seven times higher than in initially normotensive subjects (p < 0.05), cardiovascular events were reported more often (p < 0.001), and the mean electrocardiographic left ventricular voltage was higher (p < 0.01). Proteinuria was more frequent in initially hypertensive than normotensive males (p < 0.01). In summary, hypertension defined by a single BP recording at the 1963-64 screening was a risk factor for hypertension, cardiovascular morbidity and, for males, all-cause mortality 27 years later. With respect to offspring studies, our findings substantiate the classification of hypertensive and normotensive families. From 1963-64 to 1990, the BP status had changed in several couples, and the long observation period seems mandatory if a reliable definition of the family history of hypertension or normotension is to be obtained.

Adult↗
PubMed1993

The Bergen Blood Pressure Study: ambulatory blood pressure in subjects with an accurately defined family history of hypertension or normotension.

24-hour ambulatory blood pressure (BP) was monitored by non-invasive methods in 42 offspring of hypertensive families (age [mean (SD1)] 40(7) years) and 38 offspring of normotensive families (age 33(6) years). The family history was defined according to parental BP data from two surveys conducted 27 years apart. Casual BP was 137(17)/84(12) mmHg in offspring of hypertensive families and 117(9)/69(6) mmHg in offspring of normotensive families (difference: p < 0.001). Average 24-h BP was 123(10)/74(6) mmHg and 113(8)/65(5) mmHg, respectively (difference: p < 0.001). The systolic and diastolic BP difference of approximately 10 mmHg was observed between the groups throughout the monitoring period. Hypertension--defined according to a recent meta-analysis as an average 24-h BP > or = 139/87 mmHg--was found in 6 offspring of hypertensive families and in no offspring of normotensive families (p < 0.05). The 24-h systolic and diastolic BP load--the percentage of readings above 140/90 mmHg (day-time) and 120/80 mmHg (night-time)--was higher in offspring of hypertensive than normotensive families (27%/17% vs. 7%4%; p < 0.001). After adjustment for intrafamilial covariation, age, and other possibly confounding variables, the differences between the groups remained. The present findings suggest that BP in subjects with a family history of hypertension is elevated on a permanent basis, and not only when it is measured in the doctor's office.

Adult↗
PubMed1993

Cardiac effects of ACE inhibition.

Hypertension frequently is associated with a number of changes in heart structure and function, such as left ventricular hypertrophy, disturbed diastolic function, and subnormal stroke volume during exercise. Most of these changes probably are related to myocardial fibrosis. Antihypertensive agents reverse the structural and functional changes to different degrees. The hemodynamic changes in central hemodynamics at rest and during exercise were studied before and after angiotensin-converting enzyme (ACE) inhibition in 68 patients with essential hypertension (ranging from severe to moderately severe). In patients with moderately severe hypertension who were administered perindoprilat intravenously, mean arterial pressure was reduced by approximately 17% due to reduction in total peripheral resistance and no changes in heart pump function. Chronic treatment with captopril, enalapril, or lisinopril for 6-12 months induced reduction in blood pressure associated with decreased peripheral resistance. In general, there were only minor changes in cardiac output, stroke volume, and heart rate. Studies from other laboratories have shown that ACE inhibitors reverse left ventricular hypertrophy and improve left ventricular diastolic function. Captopril also appears to improve coronary circulation. The effect of ACE inhibitors on heart structure and function appears promising with regard to cardioprotection during chronic use, but long-term studies are needed to prove that this will occur in clinical practice.

Adult↗
PubMed1993

A double-blind, long-term, comparative study on quality of life, safety, and efficacy during treatment with amlodipine or enalapril in mild or moderate hypertensive patients: a multicenter study.

Amlodipine (5-10 mg, once daily) and enalapril (10-40 mg, once daily) were compared in terms of quality of life, efficacy, and tolerability, in a multicenter, double-blind trial lasting for 50 weeks in 461 mild or moderate hypertensive patients. Both drugs were similarly effective in lowering blood pressure while maintaining quality of life. Apart from class-typical effects, such as edema for calcium antagonists, and cough for angiotensin-converting enzyme inhibitors, both drugs were equally well tolerated, with few adverse effects of clinical significance. Only a few patients [eight amlodipine (4%); nine enalapril (4%)] were withdrawn from the trial due to drug-related adverse events, demonstrating that tolerability was good. Neutral to slightly beneficial effects were found in blood lipid concentrations after treatment with amlodipine. Both drugs reduced the calculated risk of coronary heart disease over the next 10 years. It was concluded that amlodipine compared favorably with enalapril as an effective and well-tolerated antihypertensive drug.

Adult↗
PubMed1993

Twenty-four-hour blood pressure load as a surrogate end-point in assessing antihypertensive therapy.

AIM: To examine the relationships among ambulatory blood pressure, blood pressure load (proportion of elevated blood pressure values over 24-h recording) and indices of hypertensive heart disease (left ventricular mass and left ventricular function) in untreated hypertensive patients. A secondary aim was to evaluate the usefulness of ambulatory blood pressure load in assessing the long-term effects of antihypertensive drug therapy. METHODS: Data were obtained from a study of 15 men with moderate to severe essential hypertension who had been treated with a placebo followed by 6-8 months of carvedilol monotherapy (25-75 mg/day). Blood pressure was evaluated by 24-h ambulatory monitoring. RESULTS: In studies of office or 'white-coat' hypertensives, ambulatory blood pressure has proved a better predictor of target organ involvement than casual (clinic) pressure. Blood pressure loads of > 50% for systolic pressure and > 40% for diastolic pressure are superior to clinic pressures, and also to the usual ambulatory monitoring parameters of mean 24-h, awake and sleeping blood pressure, in predicting left ventricular hypertrophy and abnormal diastolic performance. In the carvedilol study, the mean awake systolic blood pressure load fell from 94 to 43% and the diastolic blood pressure load fell from 84 to 27% with carvedilol treatment (P < 0.001 in both cases). Of the patients treated with carvedilol monotherapy, 60% fell into the lower risk category (< 50% systolic blood pressure and < 40% diastolic blood pressure load). CONCLUSIONS: These data support the use of blood pressure load in clinical studies of mild to moderate essential hypertension as a measure of the efficacy of antihypertensive drugs.

Antihypertensive Agents↗
PubMed1992

Long-term hemodynamic effects of antihypertensive treatment.

The cardinal hemodynamic disorder in established essential hypertension is increased total peripheral resistance. During exercise, the increase in stroke volume of the heart is abnormal. A 20-year follow-up study of the hemodynamics in essential hypertension demonstrated a progressive increase in total peripheral resistance and deterioration of the heart pump function. Long-term treatment with antihypertensive agents modifies the circulatory system in different ways. Vasodilators (angiotensin converting enzyme inhibitors, alpha 1-blockers, and calcium antagonists) all reduce total peripheral resistance, and in general, cardiac output, heart rate, and stroke volume remain unchanged. Calcium antagonists like verapamil and diltiazem reduce the heart rate approximately 10% during exercise, but since stroke volume increases, cardiac output is unchanged. Chronic treatment with conventional beta-blockers induces a permanent reduction in cardiac output and heart rate during exercise. In contrast, carvedilol--a beta 1,beta 2-blocker with alpha 1-blocking activity--prevents the immediate increase in total peripheral resistance during acute beta-blockade. In 19 patients followed by hemodynamic measurements over 6-9 months, blood pressure was well controlled by carvedilol. During exercise, total peripheral resistance decreased 6% (P less than 0.05), and the reductions in heart rate and cardiac index were less than on conventional beta-blockade. Echo-Doppler studies showed a significant reduction in the intraventricular septum of 13%.

Adrenergic beta-Antagonists↗
PubMed1992

Chronic haemodynamic effects of carvedilol in essential hypertension at rest and during exercise.

Nineteen men (mean age 44 years) with essential hypertension, WHO stage I, were studied invasively at rest and during exercise. Blood pressure was recorded intra-arterially (brachial artery), cardiac output by dye dilution method and heart rate by electrocardiography. After initial pre-drug recordings, the patients received 25 mg carvedilol orally and central haemodynamics at rest and during exercise were recorded 1 and 2 h after tablet intake to evaluate the immediate effects of carvedilol. The results indicated a combined beta-blocking and vasodilating effect. After 6-9 months of treatment, supine haemodynamics were recorded 12-24 h after the last dose and then 1 and 2 h after an additional 25 mg dose. During chronic treatment (2 h after last dose at rest supine) mean arterial pressure was reduced by 17% (P less than 0.001) and total peripheral resistance index by 6% (NS) while heart rate and cardiac index were reduced by 12%. Exercise haemodynamics demonstrated a fall in blood pressure of 17% (P less than 0.001). Exercise stroke index increased by 5% (NS), partly compensating for the reduction in heart rate of 17%. Total peripheral resistance index was reduced by 5% (NS). It is concluded that carvedilol is an effective anti-hypertensive agent in a large proportion of patients with essential hypertension. The haemodynamic mode of action reflects an alpha 1-blocking activity, particularly in situations with low sympathetic tone. During exercise the beta 1-blocking activity (demonstrated by the reduction in heart rate) is more prominent.

Administration, Oral↗
PubMed1992

Effects of carvedilol on atrial natriuretic peptide, catecholamines, and hemodynamics in hypertension at rest and during exercise.

Possible counterregulatory neurohumoral and hemodynamic responses to carvedilol (a new vasodilating nonselective beta-receptor blocker) were studied in 19 men with essential hypertension (age range, 34-59 years; mean age, 44 years). Intra-arterial pressure, cardiac output (Cardio-green), heart rate, and the vasoactive peptides norepinephrine, epinephrine, and atrial natriuretic peptide (ANP) were measured at rest supine and sitting and during 100-W bicycle exercise before and 2 h after administration of 25 mg carvedilol. The same protocol was followed after 9 months of chronic carvedilol treatment (mean dose, 52 mg/day). Carvedilol induced both acute and chronic reductions (at rest supine, 11%) in mean arterial pressure, due in part to reduction in cardiac output (5%) and in part to reduction in total peripheral resistance (5%). At rest supine, carvedilol induced a reduction in ANP (27%) that could be viewed as a counterregulatory response to decrease in cardiac output, preventing excessive blood pressure reduction. ANP decreased (18%) when the patient sat up from the supine position and increased (67%) during exercise, but no further change was seen after acute or chronic carvedilol treatment. With the patient in the sitting position, norepinephrine was 110% higher than at rest supine; during 100-W exercise, norepinephrine increased 368%. A further increase (38-86% in the three situations, respectively) was seen after the first dose of carvedilol. Epinephrine showed similar but less marked changes. Neither extracellular fluid volume nor plasma volume (isotope dilution techniques) changed significantly during the study, but the acute blood pressure response to carvedilol was directly related to changes in extracellular fluid volume.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1992

Long-term haemodynamic effects of amlodipine at rest and during exercise in essential hypertension.

Haemodynamic responses at rest and during exercise were studied in 18 patients with essential hypertension following long-term treatment with amlodipine. Patients underwent a 2-week placebo run-in period followed by a mean duration of 11 months' treatment with amlodipine 5-10 mg (mean dose 9 mg) once daily. Blood pressure was measured intra-arterially, cardiac output by dye dilution and heart rate by electrocardiogram. Amlodipine produced a mean reduction in systolic and diastolic arterial pressure of 27 and 16 mm Hg, respectively, at rest and after exercise. At rest sitting, mean systolic and diastolic arterial pressures were reduced by 16 and 14% (p less than 0.01), respectively, from initial mean values of 182.4/111.2 mm Hg. This reduction in blood pressure was associated with a marked reduction in the total peripheral resistance index of 19% (p less than 0.001). Similar responses were observed at rest supine and during exercise. No significant changes were seen in heart rate. Stroke index showed a small increase at rest and during exercise together with a trend towards an increase in cardiac index after treatment with amlodipine. Ambulatory blood pressure monitoring was carried out in 10 patients after the placebo run-in and at the end of the study. Amlodipine showed effective blood pressure control throughout the 24 h after one daily dose. The incidence of side effects was low (ankle oedema in 2 patients).

Adult↗
PubMed1992

The Bergen Blood Pressure Study: definition of hypertensive and normotensive families based on 27 years' follow-up.

The familial aggregation of hypertension is well documented. However, many studies on the familial predisposition have suffered from insufficient knowledge of parental blood pressure (BP). In the present study, the family history is defined according to parental data from two BP surveys conducted almost 30 years apart. Data from a population screening in Bergen in 1963-64 were linked with information on marital status to define couples with or without a history of hypertension. Within the screened population a total of 344 married couples, 688 individuals, matched defined age and BP criteria. Four hundred and thirty individuals, representing 270 of the 344 families initial included (79%), attended a follow-up examination in 1990. Six hundred and ninety-one offspring were registered. In all families represented at follow-up, parental BP data from the 1963-64 screening were available. In 160 families (noffspring = 393), both parents also attended the follow-up examination in 1990. In 23 families (noffspring = 54) both parents were hypertensive in 1963-64 as well as in 1990. In 22 families (noffspring = 55) both parents were normotensive at both examinations. Thus, a family data base which is assumed to be useful for studies on offspring with or without a family history of hypertension, has been established. The offspring studies include BP, 24-h ambulatory BP, electrocardiography, echocardiography, endocrine parameters, electrolytes and anthropometric variables.

Adult↗
PubMed1992

Carvedilol in hypertension: effects on hemodynamics and 24-hour blood pressure.

Nineteen men (mean age, 44 years) with moderately severe essential hypertension were studied invasively at rest and during exercise. After initial predrug recordings, patients received 25 mg carvedilol orally, and central hemodynamics at rest and during exercise were recorded 1 and 2 h after tablet intake to evaluate the immediate effects of carvedilol. Blood pressure decreased by 11% within 1 h, and the hemodynamic results indicated a combination beta-blocking and vasodilating effect. After 6-9 months of treatment (dose, 25-100 mg), supine hemodynamics were recorded, first 12-24 h after the last dose and then 1 and 2 h after an additional 25-mg dose. During chronic treatment (2 h after the last dose with the patient at rest and in the supine position), mean arterial pressure was reduced by 17% (p less than 0.001) and total peripheral resistance index was reduced by 6% (NS), whereas heart rate and cardiac index were reduced by 12%. Exercise hemodynamics demonstrated a decrease in blood pressure of 17% (p less than 0.001). Exercise stroke index increased by 5% (NS), in part compensating for the reduction in heart rate of 17%. Total peripheral resistance index was reduced by 5% (NS). Twenty-four-hour blood pressure monitoring (Accutracker II) demonstrated significant blood pressure reductions in awake as well as in asleep patients. Blood pressures decreased from 163/102 to 141/84 mm Hg in from 135/78 to 122/68 mm Hg in awake and asleep patients; respectively. Carvedilol is an effective antihypertensive agent, and the hemodynamic mode of action reflects alpha 1- and beta 1-blocking activities.

Administration, Oral↗
PubMed1991

Long-term haemodynamic effects of sustained-release trimazosin at rest and during exercise in essential hypertension.

The long-term haemodynamic effect of sustained-release trimazosin (mean daily dose 418 mg) at rest and during exercise has been examined in 14 male patients (age 30-61 y) with previously untreated mild or moderate essential hypertension. Cardiac output (dye dilution), heart rate and intra-arterial blood pressure were measured supine and sitting at rest, and during bicycle exercise. After 11 months of trimazosin treatment the mean casual blood pressure was reduced from 165/106 mmHg to 147/92 mmHg. The intra-arterial systolic and diastolic pressure was reduced by 3-7% at rest and during 50, 100 and 150 W exercise. Total peripheral resistance was reduced by 8-14% and cardiac output was slightly higher (2-8%) in all situations. Stroke volume and heart rate remained unchanged, as did body fluid volumes (isotope dilution) and body weight. Side effects were minor and transient. Thus, the haemodynamic responses to trimazosin are similar to but weaker than those of other alpha 1-adrenoceptor blockers. The efficacy of the sustained-release formulation of trimazosin was low and daily doses above 600 mg are likely to be needed by many patients.

Adult↗