A technique for chronic recording of systemic arterial blood pressure in the unrestrained rat

A technique is described for the chronic recording of systematic arterial blood pressure, respiration, and heart rate in the unrestrained rat. The surgical implantation and anchoring procedures described are compatible with the delivery of noxious electric shock and/or rewarding intracranial brain stimulation as reinforcement. Data on catheter patency are analyzed in 65 rats participating in a variety of experiments on the instrumental and classical conditioning of blood pressure responses. The results indicate that it is difficult to maintain satisfactory catheter performance beyond 2 weeks.     

Ambulatory and laboratory blood pressure in individuals with negative and positive family history of hypertension.

Undertook 24-hr ambulatory blood pressure (BP) monitoring in men and women with and without family history of essential hypertension. Cardiovascular functions were also recorded in the laboratory during mental arithmetic, image star tracing, isometric exercise, and the cold pressor test. Ambulatory daytime, but not nighttime, systolic and diastolic BP as well as heart rate (HR) level and variability was higher in those with than without family history. During sleep, HR level and variability were higher among those with family history; at rest in the laboratory, however, all cardiovascular functions were similar in both groups. The strongest laboratory-based predictor of daytime BP was stress-induced BP levels. BP reactivity also significantly predicted daytime BP but with less accuracy. The best predictor of BP and HR at sleep was resting cardiovascular functions. Thus, ambulatory BP recordings add information to resting and stress-induced levels in identifying cardiovascular risk reactions.     

The consequences of a nurse's negative evaluation of a blood pressure reading. Implications for the etiology of white-coat hypertension

The aim of this study was to show how a nurses negative evaluation of a blood pressure (BP) reading can cause an increase in BP in the following reading. Twenty-five subjects with normal pressure who had been informed that they were to participate in an epidemiological BP study took part and they were divided into two groups. After taking the first BP reading, participants from the experimental group were informed that their pressure was normal but high for their age, whereas those in the control group were told that their pressure was normal for their age. The results showed that this comment caused a significant increase in the diastolic BP of the experimental group. The theoretical and clinical implications of this reaction are discussed in relation to the phenomenon known as White-Coat Hypertension from the perspective of the theory of incubation.     

Regional cerebral blood flow response in a patient with remitted global amnesia

A case of remitted global amnesia, believed to have residual left medial temporal lobe damage, is tested by the same recognition memory paradigm used by Wood, Taylor, et al. in the previous paper. On two different testing occasions, once using an intentional and once an incidental memory procedure, the patient's right occipital flows were inversely correlated with memory accuracy and the values were very close to the regression line for 10 normals relating occipital flow to memory accuracy. The left occipital flows did not fit the regression line, however. The results were interpreted as consistent with the notion that occipital flow is inversely related to medial temporal lobe activation. Another surprising feature of this case is the unexpected persistence of amnesia for a period from about 5 to 10 years before her episode to about 2 weeks after the episode, with recovery of memory functioning for the period since that time.     

Illness representation of arterial hypertension in a sample of health professionals and the general public

This work studies the illness representation of high blood pressure in a sample of primary health care professionals and the general public in order to identify possible differences. The examination of illness representation was carried out using a Spanish adaptation of Turk et al.'s ( 1986 ) Implicit Model of Illness Questionnaire. This questionnaire assesses nine components: identity, cause, incapacity, cure, personal responsibility, controllability, changeability and chance. The results showed statistically significant differences between the general public and doctors in all the components except controllability. Results also show that nurses' responses are closer to those of the general public in the social and psychological aspects, but not in the technical knowledge of hypertension.     

Effects of single trial of heart-rate biofeedback on the arterial blood pressure, ventilation volume, and oxygen consumption during ramp bicycling exercise

We examined whether the heart rate attenuation resulting from a single trial of biofeedback during exercise occurs without any changes in oxygen consumption (VO2), ventilation volume (V(E)), and mean arterial blood pressure (M(AP)) although these variables are essential determinants for the heart-rate response during exercise. 35 subjects exercised on a cycle ergometer under two conditions while they exercised only (Control) or were trying to decrease the heart-rate response as low as possible by monitoring their own heart-rate responses as Single trial of biofeedback signals. 17 subjects could attenuate their heart rate (Can group), and their heart-rate reduction during Single trial of biofeedback was 5+/-1 bpm. The remaining subjects were unable to reduce heart rate (Cannot group). The heart-rate attenuation during Single trial of biofeedback in the Can group occurred independently of changes in VO2 and MAP but was accompanied by a significant decrease in V(E) and rating of perceived exertion (RPE). However, there was a similar decrease in V(E) in the Cannot group. These findings suggested that the heart-rate attenuation during Single trial of biofeedback was not induced by the metabolic demand of VO2 and the regulations of M(AP) and V(E) during exercise. Other mechanisms, which are probably related to the reduction of RPE, might play an important role in the heart-rate attenuation during a Single trial of biofeedback.     

Impact of the format of user instructions on the handling of a wrist blood pressure monitor

Cognitive Processing - Few studies have focused on procedural documents in the field of home medical devices, although incorrect use and usability problems can have important consequences for the...     

Regional cerebral blood flow response during rest and memory activation in a patient with global amnesia

A college professor with a classical amnesic syndrome is described. He has a WAIS IQ of 130, but dramatic memory loss for episodes ranging from a few seconds ago all the way back to portions of his childhood. The amnesia was of sudden onset, 2 years prior to the current memory tests and regional cerebral blood flow measurements. The etiology is believed, though not conclusively proven, to be medial thalamic infarction. rCBF measurements were taken on six separate occasions, four resting baseline, one memory activation, using the previous procedure of Wood, Taylor, et al., and one carbon dioxide activation. The resting baseline showed extremely low flows throughout the cortex, with some hyperfrontal response on the first baseline. With CO₂ activation, however, there was brisk, uniform reactivity, with all sites showing increased flow. This suggested that there were no prominent areas of impaired vasomotor control or probable ischemic damage in the cortical surface. During memory activation, there was also a generalized increase in flow, especially in the frontal areas. This was in sharp contrast to the pattern for normals, described by Wood, Taylor, et al., which shows a slight overall decrease in flow from baseline to memory activation. The results are interpreted in light of Talland's proposal that the amnesic syndrome reflects an arousal failure, with premature closure and shutdown of memory processing, especially at retrieval. Here the arousal failure is interpreted as an inadequate restriction or focusing of cortical activation, with resulting pathologically diffuse flow increases.     

Differences between informants about type a,anger, and social support and the relationship with blood pressure

Abstract

In a study on the influence of different natural environments on self-perception and that of significant others, behavioral manifestations of Type A, Anger, and Social Support were assessed. It was hypothesized that due to different environmental demands, participants will be perceived as displaying differences in Type A behavior, anger, and social support at home and at work. Participants were 45 university employees, constituting a convenience sample. Assessment included Type A Structured Interview scores of participants and questionnaire scores for Type A, anger, and social support of participants who were also evaluated by their spouses and work supervisors. Other risk factors for coronary heart disease (i.e., blood pressure, smoking, previous heart condition, being sedentary, and family history) and their relationships with Type A, anger, and social support were also examined.

Participants and spouses agreed significantly on all measures, whereas participants and work supervisors agreed only on Type A behavior. Spouses' and work supervisors' evaluations of the participants' behavior were not or only marginally associated. Multiple regression analysis showed that the level of disagreement between the different informants with respect to Type A and social support were associated with elevated blood pressure. These results suggest that the perception of Vpe A behavior, anger, and social support may be situationally determined.     

Effects of a checklist on self-assessment of blood glucose level by a memory-impaired woman with diabetes mellitus

This study evaluated effects of a checklist on the accuracy of self-assessment of blood glucose level by a diabetic woman with memory impairments caused by viral encephalitis. The checklist consisted of 54 steps for operating an electronic glucometer, which the subject performed in sequence and checked off when completed. Following introduction of the checklist, the percentage of steps completed correctly increased in simulated and actual blood glucose tests and yielded clinically useful information.     

Non-Markovian causality in the social sciences with some theorems on transitivity

The author argues for the importance of non-Markovian causality in the social sciences because Markovian conditions often cannot be satisfied. Two theorems giving conditions for non-Markovian causes to be transitive are proved. Applications of non-Markovian causality in psychology and economics are outlined.     

Effects of a high salt diet on blood pressure responses to acoustic stimuli in borderline hypertensive rats (BHR)

The borderline hypertensive rat (BHR) responds to environmental and dietary stressors with elevated blood pressure. The first two months of a high salt diet appear to be the time of greatest sensitivity to salt effects on the blood pressure of BHR. The current study was conducted to examine whether exposure to salt diets varying in duration for up to two months differentially affects baseline blood pressures (systolic, SBP, and diastolic, DBP) and blood pressure responses to novel acoustic stimuli in BHR and normotensive Wistar-Kyoto (WKY) rats. Male BHR and WKY were fed a control (1%) salt diet or a high (8%) salt diet for 1, 1.5, 2.5, or 8.5 weeks. SBP and DBP responses to an acoustic stimulus (85 dB, 3 kHz) were measured upon completion of the diets at 12 weeks of age. Ten acoustic trials (one stimulus/minute) were presented and blood pressure responses were recorded in 2-second blocks spanning the 10 seconds prior to and following stimulus presentation. BHR had higher resting SBP and DBP than WKY, and 8.5 weeks of 8 percent salt increased SBP markedly in BHR. SBP and DBP labilities in the initial trial were greater in BHR than WKY with high salt diet durations of 2.5 and 8.5 weeks producing greater lability in later trials. Few differences were noted in pressor responses, but BHR had more dramatic depressor responses than WKY in early trials, and BHR pressures had a more dramatic return to baseline. It appears that genetic history and salt diet can affect blood pressure lability and recovery in response to novel stimuli in genetically susceptible animals.