Many senescent individuals demonstrate an inability to regulate mean arterial pressure (MAP) in response to standing or head-up tilt; however, whether this aging effect is the result of depressed cardiac function or an inability to reduce peripheral vascular conductance remains unknown. Therefore, the purpose of this research was to investigate the effects of aging on MAP, heart rate (HR), regional blood flow (via radioactive-microspheres), and vascular conductance during head-up tilt in conscious young (4 mo; n=12) and old (24 mo; n=10) male Fischer-344 rats. Heart rate and MAP were measured continuously during normal posture and during 10 minutes of head-up tilt. Blood flow was determined during normal posture and at the end of 10 minutes of head-up tilt. Young rats increased MAP significantly at the onset of head-up tilt and generally maintained the increase in MAP for the duration of head-up tilt, while aged rats showed a significant reduction in MAP after 10 minutes of head-up tilt. In the normal posture, aged rats demonstrated lower blood flow to splanchnic, bone, renal, and skin tissues versus young rats. With tilt there were decreases in blood flow to skin, bone, and hind-limb in both age groups and in fat, splanchnic, reproductive, and renal tissues in the young. Bone blood flow was attenuated with age across both conditions in hind foot, distal femur, femur marrow, and proximal and distal tibia. Head-up tilt caused a decrease in blood flow across both age groups in all bones sampled with the exception of the hind foot. These results provide evidence that the initial maintenance of MAP in aged rats during head-up tilt occurs through decreased regional blood flow and vascular conductance, and that the fall in pressure is not attributable to an increase in tissue blood flow and vascular conductance. Therefore, reductions in arterial pressure during headup tilt are likely a result of an old age-induced reduction in cardiac performance. In addition, this is the first study to demonstrate a decreased bone vascular conductance in both young and old rats during head-up tilt.

Abstract Parkinson’s disease (PD) is a chronic and progressive neurodegenerative disease which is characterized by resting tremor, rigidity, bradykinesia and postural instability. Advanced PD is often complicated by falls, immobilisation and progressive deterioration of overall physical capability that may jointly contribute to a reduced quality of life and even to increased mortality. The purpose of this study was to identify risk factors for falls and mortality in PD, to assess the clinical correlates of balance and mobility, and to evaluate the association between orthostatic hypotension (OH), balance and mobility. From a total population of approximately 205 000 inhabitants, 125 patients with idiopathic PD were included in the study. Baseline medical data including occurrence of recent falls were collected, and patients were clinically tested for balance, mobility and orthostatic blood pressure reactions. Falls were thereafter prospectively recorded for two years using fall diaries and follow-up calls. Mortality was documented by reviewing the hospital charts four years after the baseline examination. In the cross-sectional part of the study, one-third of the patients reported recent falling. Disease duration and severity, recent falling and use of a walking aid were predictors of increased postural sway in PD. Advanced age and severity of the disease were related to impaired balance and mobility in PD patients. Severity of the disease and increased postural sway were independent risk factors for recent falling in PD, whereas measures of mobility were less important in this manner. Fifty-three percent of the patients had OH in the orthostatic test. Patients with OH had significantly increased postural sway in standing compared to patients without OH. On the contrary, OH was not associated with mobility and walking speed. In the present data, OH was not associated with the risk of falling in PD. Sixty-three percent of the study patients experienced falls and almost half of the subjects fell recurrently during the two-year follow-up. History of falling and disease severity indicated increased risk of recurrent falls in PD, while patients with slow walking speed had an increased risk of mortality. The results show that balance impairment and falls are common features in PD. Slow walking speed may be associated with increased mortality in PD.

Maintenance of stable arterial blood pressure during orthostatic challenges is a major problem after spinal cord injury (SCI). Since early participation in rehabilitation is critically important in reducing long term morbidity, recovering the ability to regulate blood pressure during therapy is essential for individuals with SCI. The objective of our study was to investigate short term cardiovascular function of able-bodied (AB), paraplegic (PARA) and tetraplegic (TETRA) subjects in response to head up tilt (HUT) as an early indicator of autonomic damage that might forewarn of future orthostatic regulatory problems. We acquired cardiovascular variables from able-bodied (AB; n=11), paraplegic (PARA; n=5) and tetraplegic (TETRA; n=5) subjects in response to HUT. The SCI patients in both groups were in their first two months post injury. Data were recorded at rest and during 7 min each at 20??, 40??, 60?? and 80?? HUT. Techniques used to estimate regulatory capability and reflex activity included: Mean values and spectral power of heart rate (HR) and arterial blood pressure (BP), baroreflex sequence measurements and cross correlation between HR and systolic blood pressure (SBP). An index of baroreflex sensitivity (BRS), baroreflex effectiveness index (BEI), and the percentage occurrence of systolic blood pressure (BP) ramps and baroreflex sequences were calculated from baroreflex sequence measurements. The spectral power of HR and BP, the cross correlation of systolic BP and heart rate (HR) were examined in low frequency (LF: 0.04-0.15 Hz) and high frequency (HF: 0.15-0.4 Hz) ranges. The BRS index was significantly (p andlt; 0.05) decreased from supine to 80o HUT in AB and TETRA. This index in PARA was the lowest at each tilt position in the three groups, and decreased with tilt. The percentage of heart beats involved in systolic BP ramps and in baroreflex sequences significantly (pandlt;0.05) rose from supine to 80o HUT in AB, was relatively unchanged in PARA and declined in TETRA. Both of these indexes were significantly (pandlt;0.05) lowerin the SCI than in the AB group at each tilt level. The BEI values were greatest in AB, and declined with tilt in all groups. Spinal cord injured patients had less power of BP and HR fluctuations than AB in both LF and HF regions. The LF spectral power of BP and HR increased with tilt in AB, remained unchanged in PARA and decreased in TETRA. The HF spectral power of HR decreased in all three groups. The peak HR / BP cross correlation in the LF region was greatest in AB, and significantly (pandlt;0.05) increased during HUT in AB, remained fairly constant in PARA, and declined in TETRA. The peak cross correlation in the HF region significantly (pandlt;0.05) decreased with tilt in all groups, and the SCI group had lower values than AB at each tilt level. We conclude that both PARA and TETRA had a smaller percentage of SBP ramps, BRS, and lower BEI than AB, likely indicating decreased stimulation of arterial baroreceptors, and less engagement of feedback control. The mixed sympathetic, parasympathetic innervations of paraplegics, or their elevated HR, may contribute to their significantly lower BRS. Our data indicate that the pathways utilized to evoke baroreflex regulation of HR are compromised by SCI and this loss may be a major contributor to the decrease in orthostatic tolerance following injury.

RESUMEN OBJETIVO: Determinar la prevalencia de Hipotensión ortostática (HO) en el adulto mayor que se hospitaliza por enfermedades médicas tanto a la admisión como al momento del alta. MÉTODO: 33 pacientes mayores de 60 años hospitalizados en los Servicios de Medicina entre los meses de Setiembre a Noviembre del 2004 participaron en el estudio. Se midió la Presión arterial a las 6:30am en posición supina y en bipedestación al 3er y 5to minuto. Considerando a la HO como la reducción de la PAS20mm. Hg. y/o PAD10mm Hg. al 3er y 5to minuto de pasar de la posición supina a la posición erguida. Además se aplicó un cuestionario para determinar los factores de riesgo y síntomas de la HO. RESULTADOS: Se encontró una prevalencia de HO de 36.4% en la población anciana estudiada. Se identificó una relación entre HO y mayor tiempo de estancia hospitalaria; Además se logró determinar que los medicamentos más usados por los pacientes con HO eran los diuréticos (66.7%) y los IECAS (44.4%); Los síntomas más frecuentes fueron los mareos (75%), caídas (58.3%), escotomas (50%). No se encontró relación entre la HO y otros factores de riesgo. CONCLUSIÓN: La prevalencia de HO encontrada es relativamente alta (36.4%) por lo que hay que tenerla en cuenta al momento de realizar el examen físico. La HO se encuentra asociada a un mayor tiempo hospitalario y a la ingesta de fármacos como diuréticos e IECAS. Se recomienda seguir investigando otras posibles asociaciones de la HO como por ejemplo mortalidad.

Orthostatic hypotension (OH) is a prevalent condition among individuals with spinal cord injury (SCI). After an injury, OH often reduces the benefit of neurorehabilitation and also prolongs periods of inactivity that lead to secondary complications. This study investigated whether the cardiovascular response to head-up tilting can be improved using functional electrical stimulation (FES) and rhythmic passive movements of the lower extremities. Participants with high thoracic and cervical SCI were recruited. While the participants were tilted head-up to 70 degrees, four conditions were applied in a random sequence: 1) no intervention, 2) rhythmic passive leg movements, 3) isometric FES, and 4) a combination of FES and passive leg movements. The measured cardiovascular parameters indicated that a combination of FES and passive leg movements induced the most desirable response to head-up tilting. The proposed intervention will enable more individuals with SCI to participate in beneficial neurorehabilitation that uses a novel tilt table.

Orthostatic hypotension (OH) is a prevalent condition among individuals with spinal cord injury (SCI). After an injury, OH often reduces the benefit of neurorehabilitation and also prolongs periods of inactivity that lead to secondary complications. This study investigated whether the cardiovascular response to head-up tilting can be improved using functional electrical stimulation (FES) and rhythmic passive movements of the lower extremities. Participants with high thoracic and cervical SCI were recruited. While the participants were tilted head-up to 70 degrees, four conditions were applied in a random sequence: 1) no intervention, 2) rhythmic passive leg movements, 3) isometric FES, and 4) a combination of FES and passive leg movements. The measured cardiovascular parameters indicated that a combination of FES and passive leg movements induced the most desirable response to head-up tilting. The proposed intervention will enable more individuals with SCI to participate in beneficial neurorehabilitation that uses a novel tilt table.

Introduction - Pure autonomic failure is a rare disorder characterized by orthostatic hypotension, absence of a compensatory rise in heart rate, and abnormal autonomic functions. In most cases, supine hypertension is seen coupled with orthostatic hypotension, making the management of these patients a big challenge. We present the case of a 74-year-old gentleman, who presented to the ED with altered mental status for a day; weakness, and falls for 3 weeks. The patient had a past medical history of Hypertension, alcoholism, and REM sleep disorder. He was being treated for erectile dysfunction for the last 10 years and had a family history of Parkinson's disease in his mother and sister. The patient was compliant with Lisinopril 40 mg, Amlodipine, and Rosuvastatin, Tamsulosin 0.4 mg. His blood pressure(BP) on presentation was ranging between 109/74-194/76 mm of Hg. Systolic BP dropped by 30mmHg after tilting the angle of the bed to 45 degrees for 1 minute with no change in HR and the patient became symptomatic in this position. Orthostatic vitals showed a dramatic drop in Systolic BP of >80mmHg with no change in heart rate. MRA and MRI showed chronic microvascular changes. The Echocardiogram, Cortisol, and TSH levels were all normal. All anti-hypertensives were discontinued and supportive treatment was started with Midodrine, Droxidopa, and Pyridostigmine, thigh-high TED hose and abdominal binders at bedtime, and Nitroglycerin patch at night for hypertension. The patient was started on fludrocortisone as he continued to drop his BP by 80 mmHg on standing. The use of TED stockings and bed tilting improved the issue of uncontrolled supine hypertension at night. Conclusion- Treatment of autonomic dysfunction continues to be challenging. There are no definitive guidelines and management is largely individualized. Both pharmacological and non-pharmacological measures are used.

Reductions in baroreflex responsiveness have been thought to increase the prevalence of orthostatic hypotension in endurance trained athletes. To test this hypothesis, cardiovascular responses to orthostatic stress, cardiopulmonary and carotid baroreflex responsiveness, and the effect of cardiopulmonary receptor deactivation on carotid baroreflex responses were examined in 24 men categorized by maximal aerobic power (V02max) into one of three groups: high fit (HF, V0-2max=67.0±1.9 ml•kg^-1•min^-1), moderately fit (MF, V0-2max=50.9±1.4 ml•kg^-1•min^-1), and low fit (LF, V0-2max=38.9±1.5 ml•kg^-1•min^-1). Orthostatic stress was induced using lower body negative pressure (LBNP) at -5, -10, -15, -20, -35, and -50 torr. Cardiopulmonary baroreflex responsiveness was assessed as the slope of the relationship between forearm vascular resistance (FVR, strain gauge plethysmography) and central venous pressure (CVP, dependent arm technigue) during LBNP<-35 torr. Carotid baroreflex responsiveness was assessed as the change in heart rate (HR, electrocardiography) or mean arterial pressure (MAP, radial artery catheter) elicited by 600 msec pulses of neck pressure and neck suction (NP/NS) from +40 to -70 torr. Pressures were applied using a lead collar wrapped about the subjects' necks during held expiration. Stimulus response data were fit to a logistic model and the parameters describing the curve were compared using two-factor ANOVA. The reductions CVP, mean (MAP), systolic, and pulse pressures during LBNP were similar between groups (P<0.05). However, diastolic blood pressure increased during LBNP m all but the HF group. (P<0.05). The slope of the FVR/CVP relationship did not differ between groups, nor did the form of the carotid-cardiac baroreflex stimulus response curve change during LBNP. changes in HR elicited with NP/NS were not different between groups (£>0.05). The range of the MAP stimulus response curve, however, was significantly less in the HP group compared to either the MP or LF group (£<0.05). These data imply that carotid baroreflex control of HR is unaltered by endurance exercise training, but carotid baroreflex control of blood pressure is impaired significantly, predisposing athletes to faintness.

Tyrimo objektas – pacientų, patyrusių kaklinės dalies nugaros smegenų sužalojimą, ortostatinės reakcijos. Pacientų, patyrusių kaklinės dalies nugaros smegenų sužalojimą, ortostatinės reakcijos – viena didžiausių problemų, trukdanti siekti reabilitacijos programos tikslų. Reabilitacijos pradžioje, keičiant kūno padėtį, jiems dažnai svaigsta galva, pykina, gali net prarasti sąmonę. Visi šie simptomai neigiamai veikia pacientą, todėl svarbu šalinti ortostatinių reakcijų pasireiškimą vertikalizuojant kuo anksčiau. Darbo tikslas – nustatyti, kuris vertikalizavimo stovas – įprastas ar ERIGO – veiksmingiau mažina pacientų, patyrusių kaklinės dalies nugaros smegenų sužalojimą, ortostatines reakcijas. Uždaviniai: 1. Įvertinti tiriamųjų kraujospūdžio pokyčius vertikalizavimo metu su skirtingais stovais. 2. Įvertinti tiriamųjų širdies susitraukimo dažnio pokyčius vertikalizavimo metu su skirtingais stovais. 3. Įvertinti pacientų savijautą po vertikalizavimo su skirtingais stovais. 4. Nustatyti vertikalizavimo procedūros su skirtingais stovais toleruojamą trukmę. Hipotezė. ERIGO – vertikalizavimo stovas su mechanizmu pasyviems kojų judesiams – veiksmingiau mažina pacientų, patyrusių kaklinės dalies nugaros smegenų sužalojimą, ortostatines reakcijas. Tyrimo metodika. Tyrime dalyvavo 24 pacientai, kurie gydėsi Palangos reabilitacijos ligoninėje 2007–2008 metais po nugaros smegenų kaklinės dalies sužalojimo. Tiriamieji buvo suskirstyti į dvi grupes po 12 žmonių. Visiems pacientams buvo... [toliau žr. visą tekstą] / Study subject: Orthostatic reactions of the patients with cervical part spinal cord injuries. Orthostatic reactions for patients with cervical part spinal cord injuries is one of the most biggest problems, which disturbs to seek the aims of rehabilitation. Patients often suffer from dizziness, nausea and even might to lose consciousness at the beginning of the rehabilitation. All these symptoms has a negative impact to patients, so it must be reduced as soon as possible. Study aim: To determine which tilt-table- simple or Erigo-has the bigger effect for patient’s, wiht cervical part spinal cord injuries, orthostatic reactions. Study goals: 1. To evaluate the blood pressure changes of the patients during verticalization with different tilt-table; 2. To evaluate the heart rate changes of the patients during verticalization with different tilt-table; 3. To evaluate the state of the patients health after verticalization with different tilt-table; 4. To determine the tolerated duration of the virtualization procedure with different tilt-table. Hypothesis: Erigo - a tilt-table with passive legs movements – is more effective in reducing orthostatic reactions of the patients with cervical part spinal cord injuries. Study methods: The study included 24 patients with cervical part spinal cord injuries which had treatment at Palanga Hospital of Rehabilitation on 2007-2008 year period. Patients were divided in to two equal groups (12 patients in each group). All patients had the same... [to full text]

Purpose: This paper attempts to develop production functions (PF) between aerobic exercise inputs and long-run health outputs. Future studies could use such PF for estimating the benefits and costs (broadly defined) of different exercise programs to help develop optimal (utility maximizing) ones. Methods: To develop the PF, the paper reviewed the biomedical literature for the major dose-response relations between health, physical fitness, and exercise. Where relevant, the paper converted the dose-response relationships from relative risks to absolute probabilities and standardized terminology and units of measures. Results: The paper develops a clear set of biological PF that illustrate, quantitatively, how increases in peak cardiorespiratory (CR) fitness as measured by a short stress test reduce the probability of all-cause mortality; how increasing intensities of short (approximately 30 min, three to five times a week) exercise sessions increase peak CR fitness or retard its age-related decline; and how consistent exercise reduces the risk of myocardial infarctions (MI). Conclusions: The exercise-long-run health PF developed in this paper should provide a useful framework for other studies to estimate the broadly defined costs and benefits of different exercise programs and to help develop optimal ones.