Relations between behavioral and cardiac autonomic reactivity to acute pain in preterm neonates

The purpose of this study was to assess relations and concordance between behavioral and physiologic reactivity to pain in preterm neonates at 32 weeks postconceptional age as a function of gestational age at birth.

The developmental character of cardiac autonomic responses to an acute noxious event in 4- and 8-month-old healthy infants

Heart rate (HR) has been widely studied as a measure of an individual's response to painful stimuli. It remains unclear whether changes in mean HR or the variability of HR are specifically related to the noxious stimulus (i.e. pain). Neither is it well understood how such changes reflect underlying neurologic control mechanisms that produce these responses, or how these mechanisms change during the first year of life. To study the changes in cardiac autonomic modulation that occur with acute pain and with age during early infancy, the relationship between respiratory activity and short-term variations of HR (i.e. respiratory sinus arrhythmia) was quantified in a longitudinal study of term born healthy infants who underwent a finger lance blood collection at 4 months of age (n = 24) and again at 8 months of age (n = 20). Quantitative respiratory activity and HR were obtained during baseline, lance, and recovery periods. Time and frequency domain analyses from 2.2-min epochs of data yielded mean values, spectral measures of low (0.04-0.15 Hz) and high (0.15-0.80 Hz) frequency power (LF and HF), and the LF/HF ratio. To determine sympathetic and parasympathetic cardiac activity, the transfer relation between respiration and HR was used. At both 4 and 8 months, mean HR increased significantly with the noxious event (p > 0.01). There were age-related differences in the pattern of LF, HF, and LF/HF ratio changes. Although these parameters all decreased (p > 0.01) at 4 months, LF and LF/HF increased at 8 months and at 8 months HF remained stable in response to the noxious stimulus. Transfer gain changes with the lance demonstrated a change from predominant vagal baseline to a sympathetic condition at both ages. The primary finding of this study is that a response to an acute noxious stimulus appears to produce an increase in respiratory-related sympathetic HR control and a significant decrease in respiratory-related parasympathetic control at both 4 and 8 months. Furthermore, with increasing age, the sympathetic and parasympathetic changes appear to be less intense, but more sustained.

An outpatient respiratory rehabilitation program:Findings from a community hospital

Objectives: To determine patient satisfaction with a community hospital's respiratory rehabilitation program and to assess changes in patient physical and emotional function and quality of life. Design: Pre- and post-program measures were made on a variety of physiological and psychosocial factors. A modified version of the Chronic Respiratory Disease Questionnaire was administered before and after the 8-week multidisciplinary and comprehensive respiratory rehabilitation program. The post-program questionnaire also included a number of service delivery and patient satisfaction and quality-of-life questions. Setting: Respiratory Rehabilitation Program at St. Joseph's Hospital, a community hospital in Brantford, Ont., in active partnership with the Brant County Lung Association. Brant County is located in Central West Ontario, and has both urban and rural areas and a population of approximately 125 000 people. Participants: Twenty-nine patients, with a diagnosis of moderate to severe chronic obstructive pulmonary disease (COPD) who were referred to the Fall 1997 and Spring 1998 programs, were enrolled in the study. Outcome measures: Changes in physical and emotional function, health knowledge, skills mastery, quality of life and satisfaction with the program. Results: Twenty-one of 29 patients completed the program. Statistically significant and clinically important improvements were found between all pre- and post-program evaluation scores (distance walked, fatigue, dyspnea, emotional function, skills mastery and health knowledge). Participants were very satisfied with the program and felt it improved their quality of life. Conclusion: The positive outcomes reported rom randomized controlled trials of respiratory rehabilitation programs can be achieved in a community hospital setting.

Behavior problems in children requiring inpatient rehabilitation treatment for asthma

Forty-eight asthmatic children (age 6-16 years), inpatients at the Hugh McMillan Medical Centre, were rated by their parents on their behavior using Achenbach's Child Behaviour Checklist. Completed checklists were used to determine normalized T scores for behavior syndromes, and these were compared against norms for clinically referred and nonreferred children. Behavior problems were elevated compared with nonreferred children for both boys and girls, with boys scoring at a clinical level. While many behavior problems were recognized, somatic complaints was a prominent syndrome, particularly for those in the 6-11-year age group.

Demographic and psychosocial characteristics of asthmatic children in a Canadian rehabilitation setting

This study investigated the demographic and psychosocial characteristics of patients attending a residential treatment program for children with asthma. Measures of background information and standardized psychosocial variables were administered to 54 inpatients over an 18-month period. Typically, our patients presented with moderate to severe chronic asthma, mostly diagnosed before 3 years of age and often associated with atopic dermatitis. The families exhibited normal levels of emotional bonding and flexibility in response to stress. Psychosocially, most children were experiencing behavioral and school-related problems, with 6-11-year-old boys exhibiting global social competency problems as well. Girls exhibited lower self-esteem. Locus of control was within the normal range for all age groups. Half the children had not previously attended an asthma education program and two-thirds of the family members either smoked and/or had a pet. The treatment implications of these characteristics of our asthma population were considered.

Examination of the physical and psychosocial determinants of health behaviour in 4-5-year-old children with congenital cardiac disease

To assess the general health and activity levels of 4- and 5-year-old children after intervention for congenital cardiac disease.

The principles and practice of interpreting cardiac rhythm strips: a seven-step model

This open learning zone article examines the cardiac cycle and the interpretation of cardiac rhythm strips. The article begins with a brief revision of related physiology followed by a description of normal sinus rhythm and the main cardiac rhythm abnormalities. The article concludes by providing easy to follow steps for use in the interpretation of cardiac rhythm strips with practice examples presented in the CPD task section.

Consequences of unlocking the cardiac myosin molecule in human myocarditis and cardiomyopathies

Myocarditis, often initiated by viral infection, may progress to autoimmune inflammatory heart disease, dilated cardiomyopathy and heart failure. Although cardiac myosin is a dominant autoantigen in animal models of myocarditis and is released from the heart during viral myocarditis, the characterization, role and significance of anti-cardiac myosin autoantibodies is poorly defined. In our study, we define the human cardiac myosin epitopes in human myocarditis and cardiomyopathies and establish a mechanism to explain how anti-cardiac myosin autoantibodies may contribute to heart disease. We show that autoantibodies to cardiac myosin in sera from myocarditis and dilated cardiomyopathies in humans targeted primarily epitopes in the S2 hinge region of cardiac myosin. In addition, anti-cardiac myosin antibodies in sera or purified IgG from myocarditis and cardiomyopathy targeted the beta-adrenergic receptor and induced antibody-mediated cAMP-dependent protein kinase A (PKA) cell signaling activity in heart cells. Antibody-mediated PKA activity in sera was abrogated by absorption with anti-human IgG. Antibody-mediated cell signaling of PKA was blocked by antigen-specific inhibition by human cardiac myosin or the beta-adrenergic receptor but not the alpha adrenergic receptor or bovine serum albumin. Propranolol, a beta blocker and inhibitor of the beta-adrenergic receptor pathway also blocked the antibody-mediated signaling of the beta-adrenergic receptor and PKA. The data suggest that IgG antibody against human cardiac myosin reacts with the beta-adrenergic receptor and triggers PKA signaling in heart cells. In summary, we have identified a new class of crossreactive autoantibodies against human cardiac myosin and the beta-adrenergic receptor in the heart. In addition, we have defined disease specific peptide epitopes in the human cardiac myosin rod S2 region in human myocarditis and cardiomyopathy as well as a mechanistic role of autoantibody in the pathogenesis of disease.

High population prevalence of cardiac troponin I measured by a high-sensitivity assay and cardiovascular risk estimation: the MORGAM Biomarker Project Scottish Cohort

Aims
Our aim was to test the prediction and clinical applicability of high-sensitivity assayed troponin I for incident cardiovascular events in a general middle-aged European population.

Methods and results
High-sensitivity assayed troponin I was measured in the Scottish Heart Health Extended Cohort (n = 15 340) with 2171 cardiovascular events (including acute coronary heart disease and probable ischaemic strokes), 714 coronary deaths (25% of all deaths), 1980 myocardial infarctions, and 797 strokes of all kinds during an average of 20 years follow-up. Detection rate above the limit of detection (LoD) was 74.8% in the overall population and 82.6% in men and 67.0% in women. Troponin I assayed by the high-sensitivity method was associated with future cardiovascular risk after full adjustment such as that individuals in the fourth category had 2.5 times the risk compared with those without detectable troponin I (P < 0.0001). These associations remained significant even for those individuals in whom levels of contemporary-sensitivity troponin I measures were not detectable. Addition of troponin I levels to clinical variables led to significant increases in risk prediction with significant improvement of the c-statistic (P < 0.0001) and net reclassification (P < 0.0001). A threshold of 4.7 pg/mL in women and 7.0 pg/mL in men is suggested to detect individuals at high risk for future cardiovascular events.

Conclusion
Troponin I, measured with a high-sensitivity assay, is an independent predictor of cardiovascular events and might support selection of at risk individuals.