Head-up tilt and hemodynamic changes during orthostatic hypotension in patients with supine hypertension

Objectives. This study assessed the mechanism(s) of the decrease in upright blood pressure in patients with supine hypertension by using the tilt test and a hemodynamic approach.Background. Orthostatic hypotension in patients with supine hypertension creates a pathophysiologic and therapeutic dilemma.Methods. We studied 28 consecutive patients with history of orthostatic intolerance amounting to recurrent syncope in 13 of them (15 men, 13 women; mean [SD] age 65 ± 11 years). They all had supine hypertension (systolic blood pressure >160 mm Hg) and orthostatic hypotension (found to be a decrease in systolic blood pressure >30 mm Hg during tilt test). Cardiac output, and orthostatic hypotension (found to be a decrease in systolic radionuclide first-pass technique (technetium-99m red blood cell tagging). Total blood volume was determined by radioiodinated serum albumin, and the ratio of cardiopulmonary to total blood volume was used as an index of venous capacitance.Results. Twenty-one patients had accentuated venous pooling defined as a tilt-induced decrease in cardiopulmonary volume/ total blood volume ratio >15% from baseline or a supine ratio < 14% (normal 16% to 18%), or both. Seven of the 28 patients had autonomic insufficiency; 6 of the 7 also had venous pooling; 1 patient had autonomic insufficiency only. Neither clinical history nor changes during tilt differentiated the subgroups. Plasma catecholamine levels increased during head-up tilt in all subgroups, and differences in their increase were not significant between patients with venous pooling and those with autonomic insufficiency. However, radionuclide hemodynamic variables revealed that patients with venous pooling compensated for the decrease in stroke volume by increasing peripheral resistance, whereas patients with autonomic dysfunction did not.Conclusions. Orthostatic hypotension in patients with supine hypertension may have multiple etiologies. Hemodynamic assessment with determination of cardiopulmonary volume and systemic vascular resistance differentiated between venous pooling and autonomic insufficiency in these patients; head-up tilt and plasma catecholamine levels did not. These findings may have important therapeutic implications.     

Effect of probiotics on hemodynamic changes and complications associated with cirrhosis: A pilot randomized controlled trial

BACKGROUNDBacterial translocation exacerbates the hyperdynamic circulation observed in cirrhosis and contributes to a more severe disease course. Probiotics may reduce bacterial translocation and may therefore be useful to redress the circulatory imbalance.AIMTo investigate the effect of probiotics on hemodynamic parameters, systemic inflammation, and complications of cirrhosis in this randomized placebo-controlled trial.METHODSThis single-blind randomized placebo-controlled study included 40 patients with Child-Pugh class B and C cirrhosis; 24 patients received probiotics (Saccharomyces boulardii) for 3 mo, and 16 patients received a placebo over the same period. Liver function and the systemic hemodynamic status were evaluated pre- and post-intervention. Echocardiography and simultaneous blood pressure and heart rate monitoring were performed to evaluate systemic hemodynamic indicators. Cardiac output and systemic vascular resistance were calculated.RESULTSFollowing a 3-mo course of probiotics in comparison to the control group, we observed amelioration of hyperdynamic circulation [a decrease in cardiac output (P = 0.026) and an increase in systemic vascular resistance (P = 0.026)] and systemic inflammation [a decrease in serum C-reactive protein levels (P = 0.044)], with improved liver function [an increase in serum albumin (P = 0.001) and a decrease in the value of Child-Pugh score (P = 0.001)] as well as a reduction in the severity of ascites (P = 0.022), hepatic encephalopathy (P = 0.048), and cholestasis [a decrease in serum alkaline phosphatase (P = 0.016) and serum gamma-glutamyl transpeptidase (P = 0.039) activity] and an increase in platelet counts (P < 0.001) and serum sodium level (P = 0.048).CONCLUSIONProbiotic administration was associated with amelioration of hyperdynamic circulation and the associated complications of cirrhosis.     

Lower limb and abdominal compression bandages prevent progressive orthostatic hypotension in elderly persons: a randomized single-blind controlled study.

OBJECTIVES: This study sought to assess the efficacy of compression bandage of legs and abdomen in preventing hypotension and symptoms. BACKGROUND: Progressive orthostatic hypotension can occur in elderly people during standing. METHODS: Twenty-one patients (70 +/- 11 years) affected by symptomatic progressive orthostatic hypotension underwent 2 tilt-test procedures, with and without elastic bandage of the legs (compression pressure 40 to 60 mm Hg) and of the abdomen (compression pressure 20 to 30 mm Hg) in a randomized crossover fashion. Leg bandage was administered for 10 min and was followed by an additional abdominal bandage for a further 10 min. Symptoms were evaluated by a 7-item Specific Symptom Score (SSS) questionnaire before and after 1 month of therapy with elastic compression stockings of the legs (prescribed in all patients irrespective of the results of the tilt study). RESULTS: In the control arm, systolic blood pressure decreased from 125 +/- 18 mm Hg immediately after tilting to 112 +/- 25 mm Hg after 10 min of sham leg bandage and to 106 +/- 25 mm Hg after 20 min despite the addition of sham abdominal bandage. The corresponding values with active therapy were 129 +/- 19 mm Hg, 127 +/- 17 mm Hg (p = 0.003 vs. control), and 127 +/- 21 mm Hg (p = 0.002 vs. control). In the active arm, 90% of patients remained asymptomatic, versus 53% in the control arm (p = 0.02). During the month before evaluation, the mean SSS score was 35.2 +/- 12.1 with dizziness, weakness, and palpitations accounting for 64% of the total score. The SSS score decreased to 22.5 +/- 11.3 after 1 month of therapy (p = 0.01). CONCLUSIONS: Lower limb compression bandage is effective in avoiding orthostatic systolic blood pressure decrease and in reducing symptoms in elderly patients affected by progressive orthostatic hypotension.     

Biomechanical analysis of posture in patients with spinal kyphosis due to ankylosing spondylitis: a pilot study.

OBJECTIVES: Patients with ankylosing spondylitis may experience a progressive spinal kyphosis, which induces a forward and downward displacement of the centre of mass (COM) of the trunk. In this pilot study, the possible mechanisms used to compensate for the displacement of the trunk COM were analysed. METHODS: Joint angles of hip, knee and ankle were determined in four patients with ankylosing spondylitis and compared to data of 18 healthy subjects. Each patient stood on a force platform and had to adopt several predefined postures, which were recorded by a video camera. RESULTS: In three patients, the hips were flexed when standing relaxed, and in all patients hip extension was limited. The knee angles of three patients were smaller and in two patients the angle of the ankles was larger compared to healthy subjects. CONCLUSIONS: The results suggest that the hip joints are at least no longer involved in balance control. This may imply that conservative therapy should focus on the prevention of restriction of the hip joints.     

Atherosclerosis of the carotid bulb is associated with the severity of orthostatic hypotension in non-diabetic adult patients: a cross-sectional study

Background: The carotid bulb has a high density of baroreceptors that play an important role in maintaining blood pressure. We hypothesized that atherosclerosis of the carotid bulb would reflect the severity of orthostatic hypotension more accurately than would atherosclerosis of other carotid artery segments.

Methods: This cross-sectional study included 198 non-diabetic adults. We measured the cardio-vascular ankle index as an index of arterial stiffness, intima-media thickness in each carotid artery segment (internal carotid artery, carotid bulb, distal and proximal portions, respectively, of the common carotid artery) as a measure of atherosclerosis, and heart rate variability as a measure of cardiac autonomic function. The sit-to-stand test was used to assess severity of orthostatic hypotension.

Results: Intima-media thickness of the carotid bulb was correlated with orthostatic systolic blood pressure change (r = ?0.218, p = 0.002), cardio-ankle vascular index (r = 0.365, p < 0.001) and heart rate variability parameters. Multivariate regression analysis revealed that among all of the segments, only intima-media thickness of the carotid bulb was an independent predictor of orthostatic systolic blood pressure change (p = 0.022).

Conclusion: Atherosclerosis of the carotid bulb was associated with severity of orthostatic hypotension, arterial stiffening and cardiac autonomic dysfunction than that of other carotid artery segments.     

Correction of cortisol overreplacement ameliorates morbidities in patients with hypopituitarism: a pilot study

CONTEXT: Hyporituitarism in adults is known to be associated with deleterious effects on body composition, lipid profile and quality of life (QoL). This was attributed to GH deficiency. The potential role of glucocorticoid overreplacement had never been investigated. OBJECTIVE: To investigate whether reduction in glucocorticoid replacement dose to more physiological one could ameliorate the "AO-GHD"-attributed symptomatology in patients with hypopituitarism. Design Eleven patients with panhypopituitarism taking 20-30 mg/day of hydrocortisone, but on no GH replacement were switched to 10-15 mg of hydrocortisone daily. Both basally and 6-12 months later, their body mass index, body composition by dual-energy X-ray absorptiometry, lipid profile, and the score of quality of life, QOL-AGHDA were measured. RESULTS: Within 6-12 months of lower hydrocortisone dose, subjects lost an average of 7.1 kg of total body fat and 4.1 kg of abdominal fat. No changes were seen in lean body mass, bone mineral content and HOMA-IR. Plasma total cholesterol and triglyceride concentrations decreased significantly (< 0.05) and the QoL improved (P = 0.018). CONCLUSIONS: Our pilot study suggests that decreasing the glucocorticoid replacement dose to approximately 15 mg/day is beneficial in terms of patients' body composition, lipid profile and quality of life.     

Increased carotid intima media thickness is associated with prolactin levels in subjects with untreated prolactinoma: a pilot study

Hyperprolactinemia is associated with endothelial dysfunction and atherogenic risk factors, but carotid intima media thickness (IMT) has not been studied in hyperprolactinemic patients. To determine whether untreated hyperprolactinemia contributes to increased carotid IMT. Thirty-one prolactinoma patients and 60 healthy controls were respectively studied. Participants underwent hormone evaluation. Anthropometric parameters (body mass index and blood pressure), inflammatory markers (high-sensitivity C-reactive protein and fibrinogen), serum glucose, insulin, lipid and apolipoprotein profiles were also determined. Endothelial function measured as the flow-mediated dilation (FMD) of a brachial artery and carotid IMT were evaluated using high-resolution ultrasonography. Multivariate linear regression analysis was applied to identify independent determinants of FMD and carotid IMT. Triglycerides, homeostasis model assessment of insulin resistance, apolipoprotein (apo)B/apoA-I ratio, high-sensitivity C-reactive protein (hsCRP) and fibrinogen were significantly higher, while apoA-I was significantly lower in patients with prolactinomas than in the controls. Meanwhile, decreased FMD and increased carotid IMT were observed in hyperprolactinemic group. Serum prolactin was positively correlated with triglycerides, apoB/apoA-I ratio, hypogonadal, hsCRP and fibrinogen (P < 0.05), but inversely associated with apoA-I and HDL-C (P ≤ 0.001). Moreover, prolactin was found negatively correlated with FMD (r = ?0.576, P < 0.0001), and positively correlated with mean carotid IMT (r = 0.652, P < 0.0001). Multivariate regression analysis revealed that prolactin determined, independent of traditional risk factors, FMD (B = ?0.589, 95 % confidence interval (CI) ?2.525 to ?0.804, P = 0.001) and mean carotid IMT (B = 0.527, 95 % CI 0.027–0.069, P < 0.0001). Hyperprolactinemia may be involved in the preclinical increase in carotid IMT, directly or by promoting atherogenic factors, including insulin resistance, low-grade inflammation and endothelial dysfunction. Additional studies are warranted to confirm our findings and explore the mechanisms underlying prolactin-associated early atherosclerosis.     

Hypovolemia contributes to the pathogenesis of orthostatic hypotension in patients with diabetes mellitus.

PURPOSE: To investigate whether body sodium content and blood volume contribute to the pathogenesis of orthostatic hypotension in patients with diabetes mellitus. SUBJECTS AND METHODS: Exchangeable sodium, plasma and blood volumes, and catecholamine, renin, and aldosterone levels were assessed in 10 patients with Type II diabetes mellitus who had orthostatic hypotension and control groups of 40 diabetic patients without orthostatic hypotension and 40 normal subjects of similar age and sex. In subgroups, clinical tests of autonomic function and cardiovascular reactivity to norepinephrine and angiotensin II infusions were performed. RESULTS: In diabetic patients with orthostatic hypotension, mean (+/- SD) supine blood pressure was 165/98 +/- 27/12 mm Hg (P <0.05 compared with other groups) and mean upright blood pressure was 90/60 +/- 38/18 mm Hg. Compared with controls, diabetic patients with orthostatic hypotension had a 10% lower blood volume. They also had less exchangeable sodium than patients with diabetes who did not have orthostatic hypotension (P <0.01). Compared with both groups of controls, diabetic patients with orthostatic hypotension had decreased 24-hour urinary norepinephrine excretion and a reduced diastolic blood pressure response to handgrip (P <0.05). Moreover, they displayed reduced products of exchangeable sodium or blood volume and sympathetic function indexes. Cardiovascular pressor reactivity to norepinephrine was enhanced (P <0.01) and beat-to-beat variation decreased (P <0.01) in both groups of diabetic patients. Microvascular complications were more prevalent in the diabetic patients with orthostatic hypotension (90% vs 35%). CONCLUSIONS: Patients who have Type II diabetes mellitus and orthostatic hypotension are hypovolemic and have sympathoadrenal insufficiency; both factors contribute to the pathogenesis of orthostatic hypotension.     

The association between antidepressant use and orthostatic hypotension in older people: a matched cohort study

Orthostatic hypotension (OH) is often reported as a significant potential adverse effect of antidepressant use but the association between phasic blood pressure (BP) and antidepressants has not yet been investigated. This cross-sectional study compares continuously measured phasic BP and prevalence of OH in a cohort of antidepressant users ≥50 years compared with an age- and sex-matched cohort not taking antidepressants. OH was defined as a drop in systolic BP ≥ 20 mm Hg or in diastolic BP ≥ 10 mm Hg at 30 seconds after standing, measured using continuous beat-to-beat finometry. Multilevel time × group interactions revealed significantly greater systolic and diastolic BP drop in antidepressant users than nonusers at 30 seconds after stand. The prevalence of OH among antidepressant users was 31% (63/206), compared with 17% in nonusers (X² = 9.7; P = .002). Unadjusted logistic regression models demonstrated that selective serotonin reuptake inhibitor use was associated with OH at an odds ratio of 2.11 (95% confidence interval: 1.25–3.57); P = .005, and this association was not attenuated when covariates including cardiac disease and depressive symptom burden were added. There was no statistically significant association between serotonin noradrenaline reuptake inhibitor or tricyclic antidepressant use and OH in unadjusted models although the study was not powered to detect changes within these subgroups. Older people taking antidepressants have a two-fold higher prevalence of OH than nonusers, highlighting the importance of screening the older antidepressant user for OH and dizziness and rationalizing medications to reduce the risk of falls within this vulnerable cohort.     

Local delivery of heparin post-PTCA: a multicenter randomized pilot study.

Bailout stenting for major dissection and threatened closure has high rates of ischemic complications. We performed a randomized trial of local heparin delivery using the infusion sleeve before bailout stenting for suboptimal angioplasty results. In phase I, 20 patients were randomized to local delivery with either 40- or 100-psi infusion pressure. In phase II, 37 patients were randomized to local delivery at 100 psi or standard therapy. Local delivery succeeded in all but one patient; overall there was no significant worsening of intimal dissection. One patient treated with 100-psi drug infusion suffered a perforation after stent placement. There were no significant differences in the composite endpoint of death, MI, CABG, urgent repeat angioplasty, and stent thrombosis at 30 days (21% vs. 0%; P = 0.18). At 6 months, the rates of myocardial infarction in phase II were 27% with local delivery vs. 10% with standard treatment (P = 0.4). Local heparin delivery in dissected vessels may be associated with increased complications and should be approached with caution.     

A prospective study of hemodynamic changes associated with distal arterial bypass in the leg

Twelve limbs with Buerger's disease were examined by measurement of segmental blood pressure, digital arterial oxygen saturation and flow velocity in the foot, before and after distal arterial bypass grafting. Eight out of 12 grafts were patent in a follow-up of 6 months to 2 years and one month. Patients with low distal blood pressure before operation obtained a small increase of the foot and toe pressures postoperatively, whereas patients with relatively good initial distal blood pressure were likely to acquire a remarkable recovery of the foot and toe blood pressures. In all 8 limbs with successful revascularization, blood flow velocity in the foot returned to normal, while the foot or the toe pressures remained pathological in 7 of the 8 limbs and digital arterial oxygen saturation did not revert to normal in 4 limbs, with ulceration after healing of the lesion. Postoperative normalization of the foot flow velocity was predictive of limb salvage. The most characteristic feature of peripheral arterial occlusive disease is a stagnation in the microvascular circulation and improvement of the reduced flow velocity is a goal of surgical or conservative treatment.