Rest Sitting Research Articles

Model-based estimation of heart movements using microwave Doppler radar sensor.

Heart rate is one of the most crucial vital signs and can be measured remotely using microwave Doppler radar. As the distance between the body and the Doppler radar sensor increases, the output signal weakens, making it difficult to extract heartbeat waveforms. In this study, we propose a new template-matching method that addresses this issue by simulating Doppler radar signals. This method extracts the heartbeat waveform with higher accuracy while the participant is naturally sitting in a chair. An extended triangular wave model was created as a mathematical representation of cardiac physiology, taking into account heart movements. The Doppler radar output signal was then simulated based on this model to automatically obtain a template for one cycle. The validity of the proposed method was confirmed by calculating the PPIs using the template and comparing their accuracy to the R-R intervals (RRIs) of the electrocardiogram for five participants and by analyzing the signals of eight participants in their natural state using the mathematical model of heart movements. All measurements were conducted from a distance of 500 mm. The correlation coefficients between the RRIs of the electrocardiogram and the PPIs using the proposed method were examined for five participants. The correlation coefficients were 0.93 without breathing and 0.70 with breathing. This demonstrates a higher correlation considering the long distance of 500 mm, and the fact that body movements were not specifically restricted, suggesting that the proposed method can successfully estimate RRI. The average correlation coefficients, calculated between the Doppler output signals and the templates for each of the eight participants, exceeded 0.95. Overall, the proposed method showed higher correlation coefficients than those reported in previous studies, indicating that our method performed well in extracting heartbeat waveforms. Our results indicate that the proposed method of remote heart monitoring using microwave Doppler radar demonstrates higher accuracy in estimating the RRI of the electrocardiogram while at rest sitting in a chair, and the ability to extract the heartbeat waveforms from the measured Doppler output signal, eliminating the need to create templates in advance as required by conventional template matching methods. This approach offers more flexibility in the measurement environment than conventional methods.

Vascular and autonomic function as early predictive biomarkers of the progression to gestational hypertension

BackgroundThe changes in endothelial function, arterial stiffness, and heart rate variability (HRV) produced in the first trimester of pregnancy in women who develop gestational hypertension (GH) are still being investigated. Objective: to evaluate the HVR, endothelial function, and arterial stiffness changes during the first trimester of pregnancy and their relationship with the development of GH MethodsA group of women normotensive during the first trimester (n = 43), who later did (GH; n = 11) or did not (no-GH; n = 32) develop GH in that pregnancy, were enrolled. In the first trimester, endothelial function and arterial stiffness were evaluated through photoplethysmography. HRV, parasympathetic (PNS), and sympathetic (SNS) indexes were measured in a 5-minute continuous electrocardiogram record at rest sitting. The Griess reaction measured urinary nitrite excretion (NOx). ResultsSystolic blood pressure (SBP) values were higher in GH (no-GH: 105.8 ± 2.0 vs. GH: 112.7 ± 3.0 mmHg; p < 0.05). Endothelial function was decreased, and arterial stiffness was increased in GH. Only in GH the arterial stiffness was correlated with SBP (Pearson’s r: 0.5594; 95%CI: 0.06106–0.8681; p < 0.05). In HRV, GH decreased low-frequency power and the ratio SD2/SD1. The inhibition of PNS was lower in GH. The NOx was reduced in GH (no-GH: 3.4 ± 0.4 vs. GH: 0.3 ± 0.1 μM/L; p < 0.001). NOx was correlated negatively with the SNS index only in GH. ConclusionsDeveloped GH is preceded early in pregnancy by endothelial dysfunction and increased arterial stiffness. In this context, there are SNS-PNS interrelation modifications with less inhibition of PNS.

Autonomic Modulation in Duchenne Muscular Dystrophy During a Computer Task: A Prospective Transversal Controlled Trial Assessment by Non-linear Techniques.

Introduction: Due to functional and autonomic difficulties faced by individuals with Duchenne Muscular Dystrophy (DMD), the use of assistive technology is critical to provide or facilitate functional abilities. The key objective was to investigate acute cardiac autonomic responses, by application of Heart Rate Variability (HRV), during computer tasks in subjects with DMD via techniques based on non-linear dynamics.Method: HRV was attained via a Polar RS800CX. Then, was evaluated by Chaotic Global Techniques (CGT). Forty-five male subjects were included in the DMD group and age-matched with 45 in the healthy Typical Development (TD) control group. They were assessed for 20 min at rest sitting, and then 5 min whilst performing the maze task on a computer.Results: Both TD and DMD subjects exhibited a significantly reduced HRV measured by chaotic global combinations when undertaking the computer maze paradigm tests. DMD subjects presented decreased HRV during rest and computer task than TD subjects.Conclusion: While there is an impaired HRV in subjects with DMD, there remains an adaptation of the ANS during the computer tasks. The identification of autonomic impairment is critical, considering that the computer tasks in the DMD community may elevate their level of social inclusion, participation and independence.

Acute hydrogen-rich water ingestion stimulates cardiac autonomic activity in healthy females

Background: Hydrogen-rich water (HRW) has been shown to have a stimulating effect on the human body. Objective: The aim of the study was to assess the influence of acute HRW intake on autonomic cardiac regulation during 50 min of rest sitting. Methods: Fourteen healthy females (age 21.7 ± 1.2 years, body mass 67.8 ± 8.7 kg, height 167 ± 5.5 cm) took part in this double-blind, randomized, placebo-controlled trial with crossover design. Heart rate variability (HRV) was monitored in the sitting position after administration of 1260 ml of HRW or placebo. Time domain indexes of HRV as the square root of the mean of the squares of differences between adjacent RR intervals (RMSSD), the standard deviation of all RR intervals (SDNN) and the ratio of SDNN/RMSSD as an index of sympatho-vagal balance were used to assess autonomic cardiac response. The values were transformed using natural logarithm (Ln). Results: After administration of HRW, we found significantly increased ratio Ln SDNN/RMSSD when comparing it to placebo in 25 min (HRW: 0.40 ± 0.30, placebo: 0.26 ± 0.25, p = .049) and 35 min (HRW: 0.44 ± 0.30, placebo: 0.28 ± 0.28, p = .029) of rest sitting. Ln SDNN was significantly increased after HRW administration when compared to placebo in 45 min (HRW: 4.41 ± 0.42 ms, placebo: 4.28 ± 0.31 ms, p = .049) of rest sitting. Conclusions: Acute HRW ingestion induced a relative increase in sympathetic activity between 25 and 35 min post-ingestion, whereas vagal activity was not affected.

安静座位&amp;middot;着衣状態での脈拍数計測のための光電脈波ラインセンサの開発

安静座位&amp;middot;着衣状態での脈拍数計測のための光電脈波ラインセンサの開発

Modest antihypertensive effect of epanolol, a beta1-selective receptor blocker with beta1 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.

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).

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)

Effect of prostaglandin inhibition by indomethacin on plasma active and inactive renin concentration in men

The effect of inhibition of prostaglandin synthesis by indomethacin on active renin and on acid-activable inactive renin was studied in nine healthy, sodium-replete men, both at rest and exercise. These volunteers were investigated after pretreatment with placebo or indomethacin, 150 mg daily for 3 days. Indomethacin induced a decrease in active (p = 0.004), total (p less than 0.001), and inactive (p = 0.02) renin at rest recumbent on average by 42, 19, and 8%, respectively, and at rest sitting on average by 45, 15, and 3%, respectively. Inhibition of prostaglandins with indomethacin reduced (p less than 0.001) active and total renin at each level of work load but not (p = 0.32) inactive renin. However, the exercise-induced stimulation (p less than 0.05) of active and total renin still occur during indomethacin. Indomethacin reduced (p less than 0.001) at rest sitting and at maximal exercise the plasma concentrations of immunoreactive prostaglandins E2 by 50 and 54%, respectively, prostaglandin F2 alpha by 36 and 39%, respectively, and 13,14-dihydro-15-keto-prostaglandin F alpha by 38 and 60%, respectively. The urinary excretion of immunoreactive prostaglandin E2 and F2 alpha was also reduced.

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

The acute haemodynamic effect of carvedilol, a new non-selective beta-receptor blocker with vasodilating effect, was examined at rest supine and sitting and during 100 W bicycle exercise in 18 patients (mean age 44 years) with essential hypertension. Intra-arterial blood pressure and heart rate were recorded continuously. Cardiac output was measured by dye dilution (Cardiogreen). Two h after the first oral dose (12.5-25 mg) of carvedilol, blood pressure was reduced in all patients sitting at rest, from 176/110 to 153/101 mmHg (P less than 0.001), associated with a reduction in cardiac index (16%; P less than 0.001) while total peripheral resistance remained unchanged or was slightly reduced. When sitting up after 2 h supine rest two patients had hypotensive reactions (excessive blood pressure drop; cold, pale, sweating skin) which disappeared after lying down with elevation of the legs and light physical exercise. The fall in cardiac index was due to reduction both in heart rate (8%, P less than 0.001) and stroke index (9%; P less than 0.01). During exercise the reduction in cardiac output was less (6%; P less than 0.05) while a clear reduction (6%; P less than 0.01) was seen in total peripheral resistance. This acute haemodynamic response is different from that seen immediately after conventional beta-blockers when total peripheral resistance always increases.

Comparative Study of Lacidipine and Nifedipine SR in the Treatment of Hypertension

The aim of this study was to compare the antihypertensive efficacy and tolerability of lacidipine, a new dihydropyridine calcium antagonist, and slow-release nifedipine (SR) in patients with mild-to-moderate essential hypertension. After a 1-month placebo run-in period, 435 patients were randomized into a double-blind, parallel-group study to receive either 4 mg of lacidipine once daily (n = 220) or 20 mg of nifedipine twice daily (n = 215). After 4 weeks, the doses for "nonresponders" were increased to 6 mg of lacidipine once daily (n = 82) and to 40 mg of nifedipine SR twice daily (n = 62). After 4 weeks, 50 mg of atenolol once daily was added to the regimens of patients still uncontrolled by lacidipine (n = 32) and nifedipine SR (n = 23) as monotherapy. Sitting blood pressure and heart rate were measured at 22-24 h after lacidipine and 10-12 h after nifedipine SR. Both calcium antagonists similarly and significantly reduced the blood pressure at rest (sitting) and on exercise, while the heart rate did not change significantly. The nature and incidence of side effects and withdrawals also did not differ between the two. In conclusion, lacidipine once daily is as effective and well tolerated as nifedipine SR twice daily in patients with mild-to-moderate essential hypertension.

Effect of long-term diltiazem treatment on central haemodynamics and exercise endurance in essential hypertension

The effects of long-term treatment with diltiazem on blood pressure, central haemodynamics and exercise endurance were studied in 16 men (mean age 52 years) with essential hypertension. Intra-arterial pressure and heart rate (HR) were monitored continuously. Cardiac output (CO) was measured by Cardiogreen at rest (supine and sitting) and during 50 W, 100 W and 150 W bicycle exercise. Haemodynamic measurements were repeated after continuous bicycling at 150 W for 20 min or until exhaustion. After 1 year on diltiazem (mean daily dose 278 mg) intra-arterial pressure was reduced (P less than 0.001) in all situations (at rest sitting from 183/108 mmHg to 157/92 mmHg (14%] due to reduction in total peripheral resistance. HR was reduced at rest (7%) and during exercise (10%). Stroke volume tended to increase while CO was unchanged. Exercise time at constant workload increased by 25%. After a peak level, intra-arterial pressure fell by 3% to 5% (P less than 0.05) due to a decrease in total peripheral resistance both before and during diltiazem treatment. Stroke volume and CO remained unchanged during endurance exercise while HR showed a small increase. Thus, there was no reduction in the overall cardiac pump function after long-term diltiazem treatment, and blood flow during exercise was maintained.

Serum Digoxin Concentration

If outpatients are allowed to rest in the supine position before their blood is sampled, serum digoxin increases. In a recent study, the serum digoxin concentration after 2-h standardized supine rest correlated better with the clinical status of patients than the value before rest. In the present study, 21 outpatients were studied on 2 consecutive days, approximately 24 h after the latest dose of digoxin. Blood samples for the assay of serum digoxin were taken on arrival at the department and after 1.5- and 2-h rest either supine or sitting (random order). The increases after 1.5-h rest were 12% (0-25%; p less than 0.001) and 12% (-3-47%; p less than 0.001), supine and sitting, respectively. The respective increases after 2-h rest were 14% (-11-32%; p less than 0.001) and 16% (0-74%; p less than 0.001). There were no statistically significant differences between the increases in serum digoxin concentration after supine and sitting rest. These results make it possible to recommend standardized rest in the sitting position (1.5-2 h) for outpatients before blood samples are collected when reliable serum digoxin analyses are of importance.

Comparison of long-term hemodynamic effects at rest and during exercise of lisinopril plus sodium restriction versus hydrochlorothiazide in essential hypertension

To investigate whether sodium restriction might replace thiazides in promoting blood pressure (BP) reduction by angiotensin-converting enzyme inhibitors, the long-term hemodynamic effect of lisinopril plus sodium restriction versus lisinopril plus hydrochlorothiazide was compared at rest and during dynamic exercise in 2 groups of essential hypertensive patients. Mean pretreatment intraarterial BP at rest sitting was 177/107 mm Hg. The patients were randomly allocated to lisinopril combined with either low salt diet (low salt group, n = 13) or hydrocheorothiazide (diuretic group, n = 12). After 1 year of treatment the mean dose of lisinopril was 25 mg in both groups. In the low satt group sodium excretion was reduced from 188 to 129 mmol/24 hours (p < 0.01). In the diuretic group sodium excretion was unchanged with a mean dose of hydrochlorothiazide of 19 mg. BP was reduced (p < 0.001) in both groups: at rest 16 and 21% and during exercise 10 and 13% in the low satt and the diuretic groups, respectively. Total peripheral resistance was reduced (p < 0.05) in both groups: at rest 14 and 7% and during exercise 8 and 5% in the low satt and the diuretic groups, respectively. Overall cardiac output was reduced (p < 0.05) in the diuretic group but remained unchanged in the low salt group. Thus, lisinopril—either in combination with a diuretic or sodium restriction—induces marked reduction in BP due to decreases in peripheral vascular resistance both at rest and during exercise. Lisinopril plus low salt diet reduces the risk of unwanted metabolic effects and toads to more complete hemodynamic normalization than lisinopril plus a diuretic and should be preferred when this leads to satisfactory BP control.

Chronic Hemodynamic Effects of Tiapamil and Felodipine in Essential Hypertension at Rest and During Exercise

Sixteen men with previously untreated diastolic blood pressure of 100-120 mm Hg were studied hemodynamically at rest supine and sitting and during a 100 W bicycle exercise. Blood pressure (BP) was recorded intra-arterially, and cardiac output (CO) by the dye-dilution method. After initial study, patients were treated with tiapamil in increasing doses (300-600 mg b.i.d., with a mean daily dose of 980 mg). The patients were restudied and then changed to felodipine (5-10 mg b.i.d., with a mean daily dose of 15 mg). Casual (cuff) BP at rest sitting was as follows: end placebo, 166/105 mm Hg; 1 year of tiapamil, 148/92 mm Hg; 1 year of felodipine, 139/86 mm Hg. Pretreatment hemodynamic results at rest sitting were as follows: BP, 169/105 mm Hg; MAP, 129 mm Hg; cardiac index (CI), 2.43 L/min/m2; total peripheral resistance index (TPRI), 4,305 dyn s/cm-5/m2. Both drugs reduced systolic (SAP), diastolic (DAP), and mean (MAP) arterial pressure significantly in all situations. BP reduction seemed to be more pronounced on felodipine than on tiapamil. Felodipine reduced MAP by 15% at rest supine, 14% at rest sitting, and 11% during exercise. The BP reduction was entirely due to reduction in TPRI (15, 16, and 13%, respectively). CI as well as stroke index (SI) and heart rate (HR) were unchanged. Tiapamil did not reduce TPRI significantly and the fall in BP was due to a combination fall in TPRI and CI.

Acute and long-term hemodynamic effects of tiapamil at rest and during exercise in essential hypertension

The first dose and long-term hemodynamic responses to tiapamil--an aralkylamine calcium-channel blocker--were studied both at rest and during exercise in 18 male patients (mean age, 45 years) with essential hypertension (EH). Blood pressure (BP) was measured intra-arterially, cardiac output (CO) was measured by dye dilution and heart rate (HR) was measured by electrocardiogram. One hour after the first oral dose of 600 mg tiapamil, mean arterial pressure (MAP) fell 14%. Total peripheral resistance (TPR) fell 21%, while HR and CO increased 7% and 11%, respectively. Thereafter the effects leveled off. After 11 months of chronic tiapamil therapy (mean dose 980 mg per day), MAP was reduced 11% at rest sitting. The reduction in BP was associated with a modest reduction in TPR. Similar responses were seen at rest supine and during 100-W bicycle exercise. A small reduction was seen in HR while CO was preserved. In conclusion, tiapamil exerts a moderate antihypertensive effect, both at rest and during exercise, through reduction of TPR without a fall in heart pump function. The long-term hemodynamic changes are rather similar to those of verapamil.

Central Hemodynamic Effects at Rest and During Exercise of Acute and Chronic Treatment with Nisoldipine in Essential Hypertension

The acute and chronic hemodynamic effects of nisoldipine were studied in 19 patients (17 men, 2 women; mean age 43 years) with essential hypertension at rest supine and sitting and during steady state 100 W bicycle exercise. At rest supine, the first dose response (1 h) was reduction of intraarterial (IA) pressure (9%) and total peripheral vascular resistance (TPR; 19%) and rise in heart rate (HR; 9%) and cardiac output (CO; 12%). Thereafter, the effect leveled off: at 3 h, IA pressure, CO, and TPR were reduced 6%, 1%, and 4%, respectively. Similar results were seen at rest and during exercise. After 1 year treatment, the changes were more marked: at rest, IA pressure and TPR fell (16% and 20%, respectively) while stroke volume and CO rose slightly (4% and 6%, respectively). There was no reflex tachycardia. During 100 W exercise, IA pressure fell (14%) due to reduction both in TPR (7%) and CO (6%). Thus, at rest, nisoldipine lowers blood pressure by reduction of TPR both acutely and chronically. The initial rise in CO is lost after long-term therapy. During exercise, falls in both TPR and CO contribute to the hypotensive effect.

Acute and chronic haemodynamic effects of doxazosin in hypertension at rest and during exercise.

The acute and chronic haemodynamic effects of doxazosin were studied in 14 patients (10 males, four females) with essential hypertension, at rest supine and sitting and during 100 W bicycling exercise. Blood pressure (BP) was recorded intra-arterially in the brachial artery, cardiac output (CO) was measured by Cardiogreen and heart rate (HR) by ECG. One hour after injection of doxazosin 0.5-1.0 mg i.v., mean arterial pressure (MAP) was reduced by 8% at rest supine, 12% at rest sitting and 10% at 100 W (all changes statistically significant), associated with a reduction in total peripheral resistance index (TPRI) of 5% at rest supine, 9% at rest sitting (P less than 0.01) and 14% at 100 W (P less than 0.001). HR was slightly increased (5%, NS) and cardiac index (CI) was unchanged during rest and slightly increased during exercise (4%, P less than 0.05). Patients were then given doxazosin capsules (2-16 mg once daily), aiming at a casual BP of less than or equal to 140/90 mmHg without side-effects. Central haemodynamics were restudied after 1 year. After 1 year of doxazosin treatment, MAP was reduced by 13% at rest supine, 16% at rest sitting and 17% at 100 W (all P-values less than 0.001). TPRI was reduced by 19% at rest supine, 20% at rest sitting and 18% at 100 W (all changes statistically significant). CI was increased by 8% at rest supine (P less than 0.05) but was unchanged sitting and at 100 W. It is concluded that doxazosin lowers BP through a reduction in TPRI acutely as well as chronically, without reductions in CO. BP control was maintained over 1 year without side-effects. Thus, doxazosin normalizes central haemodynamics in patients with mild to moderate essential hypertension, both at rest and during exercise.

Hemodynamic effects of verapamil in essential hypertension at rest and during exercise.

In recent years the calcium antagonist verapamil has been used in the treatment of essential hypertension. Relatively little work has been done to elucidate its long-term haemodynamic effects at rest and during exercise. Ten males with previously untreated essential hypertension in WHO stage I, aged 35-55 years, were studied on an outpatient basis. Oxygen consumption, heart rate, cardiac output ( Cardiogreen ) and intra-arterial brachial pressure were recorded at rest in the supine and sitting position and during steady state work at 50, 100 and 150 W. As expected, the hypertension was associated with an increase in total peripheral resistance. The subjects were treated with verapamil 120-240 mg daily as the sole drug for one year. The haemodynamic study was then repeated. One subject demonstrated a slight increase in blood pressure at rest and during exercise, while there was a blood pressure reduction in the other 9. The nonresponding patient was excluded from the statistical evaluation. The main results were as follows: There was a statistically significant reduction in systolic, diastolic and mean arterial pressure at rest as well as during exercise. The reductions reached about 10% at rest, slightly less during exercise. The blood pressure reduction was associated with a statistically significant reduction in total peripheral resistance at rest only. During exercise, the reduction in resistance was modest (about 5%). The heart rate was practically unchanged during supine rest, but decreased about 8% at rest sitting and during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Dissociation between Plasma Prostaglandins E and Fα, Renin and Catecholamines in Hypertensive Patients

1. Plasma prostaglandins (PGE and PGFα) and catecholamine concentrations, and plasma renin activity were measured during an uninterrupted graded exercise test on the bicycle ergometer in 11 hypertensive patients. Blood was withdrawn from the brachial and pulmonary artery after 30 min recumbent rest, after 15 min rest sitting and at the final work load of the exercise test, which averaged 143 ± 16.5 W. 2. Exercise did not provoke a significant change in these plasma PGE or PGFα concentrations, but a rise (P &amp;lt; 0.001) in arterial plasma renin activity and (nor)adrenaline concentration was observed. It is thus unlikely that prostaglandins E or Fα are an important determinant of release of plasma renin during exercise.