Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two validation procedures are currently available for the evaluation of ambulatory blood pressure measurement systems--the standard of the Association for the Advancement of Medical Instrumentation (AAMI) and the protocol of the British Hypertension Society (BHS). Both are in the process of revision. Four systems for measuring 24-hour ambulatory blood pressure--SpaceLabs 90207, Novacor DIASYS 200, Del Mar Avionics Pressurometer IV, and Takeda TM-2420--were evaluated according to the BHS protocol, which incorporates many of the features of the AAMI standard, under similar conditions by the same personnel and in the same subjects, so as to examine the relative merits of the two evaluation procedures. Three recorders of each model were subjected to a before-use inter-device variability test, followed by an in-use phase and an after-use inter-device variability test. The main validation test was carried out in 86 subjects with a wide range of pressures, the results being analyzed according to the BHS grading system and the AAMI validation criteria. The SpaceLabs 90207 and the DIASYS 200 achieved B and C grades, respectively, according to the BHS protocol and also satisfied the AAMI criteria for accuracy. The Pressurometer IV achieved a Grade C rating for systolic pressure and a Grade D rating for diastolic pressure and the Takeda TM-2420 achieved Grade D ratings for both systolic pressure and diastolic pressure. Both these devices failed to fulfil the AAMI criteria for accuracy and both failed to function in the main validation test and had to be replaced.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:The quest for better validation: a critical comparison of the AAMI and BHS validation protocols for ambulatory blood pressure measurement systems. 827 39

Before the diagnostic potential of 24-hour non-invasive BP measurement can be assessed, the accuracy of ambulatory recorders must be established, and normal reference values determined. The accuracy criteria of four ambulatory BP measuring systems (the SpaceLabs 90207, the Novecor DIASYS 200, the Takeda TM-2420 and the Del Mar Avionics Pressurometer IV) have been assessed according to the British Hypertension Society (BHS) protocol, and the Medilog, Suntech Accutracker II and the SpaceLabs 90202 according to the standard of the Association for the Advancement of Medical Instrumentation (AAMI). The SpaceLabs 90202 and 90207, the DIASYS 200 and the Medilog fulfilled the AAMI criteria. The best devices with the BHS grading system are the SpaceLabs 90207 and the DIASYS 200. Normal reference values for daytime, night-time and 24-hour ambulatory BP have been provided by the Allied Irish Bank study of 815 healthy individuals, which showed clear age and sex differences. The mean 24-hour ambulatory pressure for the entire group was 118/72 mm Hg. 24-hour ambulatory BP measurement possesses clear advantages over conventional clinic measurement in evaluating drug efficacy, as it provides many more readings, allowing for the possibility of reducing the number of patients in antihypertensive drug studies and eliminating the need for a placebo-controlled crossover design. It allows assessment of night-time BP, which is important in view of the fact that excessive BP reduction may put patients at risk of myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Ambulatory blood pressure measurement in the diagnosis and management of hypertension. 179 15

To evaluate the present role of fundal examination in the assessment of the hypertensive patient, 348 hypertensive subjects, mostly with borderline or mild hypertension, were studied with direct ophthalmoscopy. The exam was always performed by the same observer. The degree of left ventricular hypertrophy was also evaluated with ECG and echocardiography. Blood pressure was measured with 24-hour ambulatory monitoring, using either the Del Mar Avionics Pressurometer II and IV, the Spacelabs 5200 or the A & D TM-2420. Signs of hypertensive retinopathy were found in 51% of the subjects. The degree of retinopathy, defined according to a modified Keith-Wagener grading system, was highly correlated with average 24-hour mean blood pressure (r = 0.31; p less than 0.0001). Based on ECG, 16% of the subjects had left ventricular hypertrophy, while 23% showed an echocardiographic left ventricular mass, indexed by body surface area, above the normal limits. Left ventricular mass index was correlated with ambulatory blood pressure levels, but at a lower level of statistical significance (r = 0.19; p less than 0.001) compared to the degree of retinopathy. No correlation was found between 24-hour blood pressure and ECG findings. Ophthalmoscopy proved to be more sensitive than echocardiography and ECG in indexing 24-hour blood pressure load, while the specificity of the 3 exams was similar. The present data indicate that fundal examination is a sensitive indicator of the vascular consequences of increased blood pressure and is therefore useful in the assessment of the hypertensive patient, while the more expensive echocardiography is not of great clinical value in borderline and mild hypertension.
 ...
PMID:[Role of ophthalmoscopy in arterial hypertension: a problem revisited]. 183 70

The aim of the study was to assess the usefulness of 24-hour blood pressure (BP) and heart rate (HR) monitoring in patients with "resistant" hypertension. 30 patients (44.1 +/- 9.9 years) with diastolic BP 100 mm Hg or more in spite of treatment with three or more antihypertensive drugs were studied. Ambulatory recording of BP and HR was performed by means of Del Mar Avionics monitoring system 9000. Mean recording time was 21.5 hours and mean number of measurements during one recording--56.7. Mean ambulatory systolic and diastolic BP values were significantly lower than mean value of three casual measurements (146.0 +/- 24.6 vs 171.5 +/- 21.2 mm Hg for systolic and 97.2 +/- 11.3 vs 110.4 +/- 7.5 mm Hg for diastolic BP p less than 0.01) In 14 (46.6%) systolic BP and in 10 patients (33.3%) diastolic BP were normal. The patients with normal and abnormal ambulatory BP recordings did not differ in regard to age and mean clinic BP levels. However, patients with abnormal ambulatory BP recordings were more often overweight and showed a greater frequency of left ventricular hypertrophy and family history of hypertension and its complications. The results of the study show that ambulatory BP monitoring may be of value in assessing the response to antihypertensive treatment in patients with so called resistant hypertension as judged on the basis of clinic pressure.
 ...
PMID:[Ambulatory 24-hour blood pressure monitoring in patients with resistant hypertension]. 207 34

To evaluate possible correlations between cardiac arrhythmias and circadian pattern of blood pressure (BP) and of heart rate (HR), we studied 2 groups of 20 males with stable arterial hypertension of mild to moderate entity, with (Group I) or without (Group II) left ventricular hypertrophy (LVH). In patients with LVH the mean age (56 vs 46 years), the duration of the hypertensive state (48.1 vs 15.7 months), the thickening of interventricular septum (IVS; 13.7 vs 9.6 mm) and of the posterior wall of the left ventricle (13.2 vs 9.2 mm) and the mass of LV (149.8 vs 99.7 g/m2) were significantly greater (p less than 0.01). On the contrary, the 2 groups did not show significant differences concerning casual BP determined in the morning (178.3/108.4 vs 171.5/106.2 mmHg). After a pharmacological washout of 2 weeks, patients underwent a noninvasive, intermittent, monitoring of BP (every 15 min during daytime and every 30 min from 11 pm to 7 am), using a pressure meter II Del Mar Avionics, and a continuous monitoring of ECG for 24 hours, employing an instrument 445/B Del Mar Avionics. Mean 24-hour BP was not different in the 2 groups of patients (161.7/99.0 vs 158.2/98.3 mmHg); however, patients with LVH showed a significantly greater variability of BP in the morning (7 am-3 pm), while mean 24-hour HR was significantly less (71.6 vs 78.2 b/min).(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[Cardiac arrhythmias in hypertensive subjects with and without left ventricular hypertrophy compared to the circadian profile of the blood pressure]. 215 Mar 45

Noninvasive recording of blood pressure (BP) with a portable Del Mar Avionics monitor (USA) revealed its abnormal circadian rhythm in patients with renovascular hypertension or arterial hypertension caused by adrenal aldosteroma. Surgical treatment was shown to result in a significant decrease in blood pressures and normalization of its circadian rhythm in the early postoperative period.
 ...
PMID:[Effects of surgical treatment on circadian variations of arterial pressure in patients with primary aldosteronism and renovascular hypertension]. 239 3

Ketanserin is a new potent antiserotonergic drug which, unlike previous ones, is selective for S2-serotoninergic receptors and does not have an agonist action. A trial was carried out on medium-term treatment with ketanserin or propranolol in subjects suffering from mild to moderate hypertension. The trial was designed as a double-blind crossover randomized study comparing either ketanserin or propranolol with placebo. Thirteen patients completed the study, which was divided into two groups (A and B). Systolic (SBP), diastolic (DBP) and mean (MBP) blood pressures were measured by non-invasive, intermittent ambulatory monitoring performed using a Pressurometer II, from Del Mar Avionics. Heart rate was measured using a continuous electrocardiogram monitoring. Systolic blood pressure was significantly reduced both after ketanserin (A:11.1%; B:10.8%) and propranolol (A:11.7%; B:11.8%) but in group A its decrease was more pronounced after propranolol (P less than 0.01). Diastolic blood pressure was significantly reduced both after ketanserin (A:11.5%; B:11.1%) and propranolol (A:11.4%; B:11.9%), as was MBP (A:11.9%; B:11.8% for ketanserin and A:11.9%; B:11.9% for propranolol). The heart rate diminished significantly only after propranolol administration (P less than 0.01). Ambulatory monitoring showed a significant 24-h reduction of SBP after administration of propranolol (P less than 0.0025) and ketanserin (A:P less than 0.0025, B: P less than 0.005). Diastolic blood pressure was also significantly reduced after ketanserin (P less than 0.0005) and propranolol (A: P less than 0.0025, B: P less than 0.0005). The heart rate obtained by continuous electrocardiogram monitoring diminished significantly only after propranolol administration (P less than 0.0005). No significant changes of circadian behaviour of blood pressure were observed.
 ...
PMID:Effects of ketanserin on ambulatory blood pressure monitoring in patients with essential hypertension. 293 8

Indirect automatic 24-hour blood pressure monitoring has been found to be reliable and valid and thus has been introduced for the evaluation of dosage and efficacy of antihypertensive drugs. The present double-blind placebo-controlled randomized long-term study reports the therapeutic results of the oral administration of a new beta-adrenergic blocking agent, carvedilol, with direct vasodilator activity in patients with primary hypertension. The antihypertensive effect was acute at onset and comparable in the supine and standing position judged by casual blood pressure readings. Indirect automatic blood pressure monitoring demonstrated a good antihypertensive effect throughout daily activities after single oral dosage. Despite some technical problems with the apparatus (Pressurometer III, Del Mar Avionics), a circadian pattern could be documented in both untreated and treated patients. Blood pressure and heart rate were normally distributed but less variable during treatment. The long-lasting antihypertensive effect was comparable to the commonly used beta-blocker metoprolol. A significantly reduced awakening blood pressure in the morning may indicate a beneficial effect on a possible prognostic factor in arterial hypertension.
 ...
PMID:Follow-up of a method of twenty-four-hour indirect blood pressure monitoring: evaluation of carvedilol, a new antihypertensive agent. 332 Jul 88

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.
 ...
PMID:The role of ambulatory blood pressure monitoring in the evaluation of adolescent hypertension. 400 37

To test the usefulness of noninvasive ambulatory 24-hour blood pressure recording, the Del Mar Avionics system was used in a double-blind clinical trial in which 31 hypertensive patients were randomly allocated to receive placebo or pafenolol (25 mg or 50 mg), a novel, long-acting, highly selective beta-blocker, once daily. The results of 24-hour blood pressure and heart rate recording after 4 weeks of treatment were compared with a previous 24-hour recording performed after a 4-week placebo run-in period using the 3-hour mean of recordings performed every 7.5 minutes both day and night. Furthermore, 24-hour means were analyzed in each patient before and after 4 weeks. The system was easy to use and, judging from two placebo periods in the same patients, the reproducibility was good. The 24-hour blood pressure and heart rate recordings showed a clear dose-response relationship for pafenolol that could not be detected by ordinary casual readings. A daily dose of 25 mg of pafenolol significantly reduced blood pressure during the 9 hours after tablet intake (p less than 0.01), while 50 mg per day of pafenolol resulted in a significant reduction throughout the 24-hour period (p less than 0.01). The same pattern was seen for heart rate, which indicates a greater degree of beta-blockade during treatment with the higher dose. These results indicate that the tested noninvasive equipment is a useful tool for monitoring ambulatory 24-hour blood pressure. It gives important information impossible to obtain from single casual readings. This noninvasive method should be further evaluated to define its place in clinical work and as a research tool.
Hypertension
PMID:Monitoring 24-hour blood pressure in a drug trial. Evaluation of a noninvasive device. 404 Aug 87


1 2 3 4 Next >>