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Biomedical subjects

D K Moser

Publications and source records attributed to D K Moser.

At least 37 records · Page 2Linked to original sources
PubMed1998

Pathophysiology of heart failure update: the role of neurohumoral activation in the progression of heart failure.

Understanding the pathophysiologic mechanisms responsible for producing heart failure is necessary before effective treatments can be developed that increase survival and improve quality of life. Recent advances in the treatment of heart failure can be traced directly to improved appreciation of the role of neurohumoral activation in the pathophysiology of heart failure. Initially adaptive, neurohumoral activation ultimately results in a series of overadjustments that actively participate in the progression of heart failure. In this article, the role of neurohumoral activation, ventricular remodeling, and various peripheral vascular abnormalities in the pathophysiology of heart failure are explored.

Disease Progression↗
PubMed1997

The physician's role in minimizing prehospital delay in patients at high risk for acute myocardial infarction: recommendations from the National Heart Attack Alert Program. Working Group on Educational Strategies To Prevent Prehospital Delay in Patients at High Risk for Acute Myocardial Infarction.

Physicians and other health care professionals play an important role in reducing the delay to treatment in patients who have an evolving acute myocardial infarction. A multidisciplinary working group has been convened by the National Heart Attack Alert Program (which is coordinated by the National Heart, Lung, and Blood Institute of the National Institutes of Health) to address this concern. The working group's recommendations target specific groups of patients: those who are known to have coronary heart disease, atherosclerotic disease of the aorta or peripheral arteries, or cerebrovascular disease. The risk for acute myocardial infarction or death in such patients is five to seven times greater than that in the general population. The working group recommends that these high-risk patients be clearly informed about symptoms that they might have during a coronary occlusion, steps that they should take, the importance of contacting emergency medical services, the need to report to an appropriate facility quickly, treatment options that are available if they present early, and rewards of early treatment in terms of improved quality of life. These instructions should be reviewed frequently and reinforced with appropriate written material, and patients should be encouraged to have a plan and to rehearse it periodically. Because of the important role of the bystander in increasing or decreasing delay to treatment, family members and significant others should be included in all instruction. Finally, physicians' offices and clinics should devise systems to quickly assess patients who telephone or present with symptoms of a possible acute myocardial infarction.

Algorithms↗
PubMed1997

Australian patients' delay in response to heart attack symptoms.

OBJECTIVES: To examine delay in seeking treatment among patients with an evolving acute myocardial infarction (MI), and to identify factors which contributed to this delay. DESIGN: Patient interview combined with medical record review. PARTICIPANTS AND SETTING: 317 patients with confirmed diagnosis of acute MI interviewed within 72 hours of admission to three hospitals. MAIN OUTCOME MEASURES: Delay from onset of symptoms to arrival at hospital, and cognitive, emotional, sociodemographic and clinical factors which contributed to increased prehospital delay. RESULTS: Median prehospital delay was 6.4 hours; 41% of patients delayed less than four hours, while 28% delayed less than two hours. Prehospital delay was increased in patients with fewer years of education (P = 0.001), lower income (P = 0.003) and transportation to the hospital by private car rather than ambulance (P = 0.02). Delay time was increased by several cognitive and emotional processes (P < 0.001), such as waiting to see if symptoms would go away, being too embarrassed to ask for assistance, and not recognising the importance of symptoms. Delay time was increased with heartburn, breathlessness or intermittent symptoms and decreased with sweating and dizziness (P < 0.05). Independent predictors of increased prehospital time (P < or = 0.01) were fewer than 10 years of education, not wanting to trouble anyone, failing to recognize the symptoms of delay, and the intermittent nature of symptoms. CONCLUSION: Over 50% of acute MI patients delay seeking treatment by six hours or more. Many factors related to cognitive and social processes that contribute to this delay may be remediable with appropriate patient and community education.

Educational Status↗
PubMed1997

The psychological consequences of cardiopulmonary resuscitation training for family members of patients at risk for sudden death.

OBJECTIVES: The purpose of this study was to determine psychological consequences of teaching cardiopulmonary resuscitation (CPR) to family members of patients at risk for sudden death. METHODS: Patient-family pairs (n = 337) were randomized into one of four groups: control, CPR only, CPR with cardiac risk factor education, and CPR with a social support intervention. Only family members received CPR training. Data on emotional state and psychosocial adjustment to illness were collected at baseline, 2 weeks, and 3 and 6 months following CPR training. RESULTS: There were no significant differences in the emotional states of family members across the four groups. However, significant differences in psychosocial adjustment and emotional states occurred in patients across treatment groups following CPR training. Patients whose family members learned CPR with the social support intervention reported better psychosocial adjustment and less anxiety and hostility than patients in the other groups. Control patients reported better psychosocial adjustment and less emotional distress than patients in the CPR-only and CPR-education groups. CONCLUSIONS: These findings support tailoring family CPR training so that instruction does not result in negative psychological states in patients. The findings also illustrate the efficacy of a simple intervention that combines CPR training with social support.

Aged↗
PubMed1997

Voluntary control of vascular tone by using skin-temperature biofeedback-relaxation in patients with advanced heart failure.

BACKGROUND: Advanced heart failure is characterized by activation of the sympathetic nervous system and intense vasoconstriction. Biofeedback-relaxation techniques have been used successfully to treat conditions with similar pathophysiological features. OBJECTIVES: The purpose of this study was to determine if conscious control of skin temperature via a biofeedback-relaxation technique could produce vasodilation and alter central hemodynamic status and circulating levels of catecholamines in patients with heart failure. METHODS: Forty patients with advanced heart failure were randomly assigned to either an intervention or a control group. The study was done in a special cardiac step-down unit accepting patients for hemodynamic monitoring. The patients in the intervention group had one session of skin-temperature biofeedback augmented by imagery of hand warmth and modified progressive muscle relaxation. Skin temperature, systemic vascular resistance, cardiac output, plasma levels of norepinephrine and epinephrine, oxygen consumption, respiratory rate, and pulmonary wedge pressure were measured before and after the biofeedback session. Control patients had the same measurements made but were not given instruction in biofeedback-relaxation techniques. RESULTS: Patients in the biofeedback-relaxation and control groups had comparable clinical profiles at baseline. Patients undergoing biofeedback-relaxation showed the following changes: (1) increase in skin temperature of 3.1 +/- 2.8 degrees F (1.7 +/- 1.5 degrees C) in the finger and 1.5 +/- 5.2 degrees F (0.4 +/- 1.2 degrees C) in the foot, (2) increase in cardiac output of 0.30 +/- 0.33 L/min, (3) decrease in systemic vascular resistance of 152 +/- 225 dyne.sec.cm-5, and (4) decrease in respiratory rate of 4.5 +/- 3.2 breaths per minute. The biofeedback group exhibited no changes in catecholamine levels or oxygen consumption. No changes in any of these parameters were seen in the control group. DISCUSSION: Despite the presence of marked vasoconstriction in patients with advanced heart failure, a single session of biofeedback-relaxation can increase finger temperature and cardiac output and decrease systemic vascular resistance and respiratory rate, apparently without effect on systemic levels of catecholamines or oxygen consumption.

Biofeedback, Psychology↗
PubMed1997

Six-minute walk test and heart rate variability: lack of association in advanced stages of heart failure.

BACKGROUND: The 6-minute walk and heart rate variability have been used to assess mortality risk in patients with heart failure, but their relationship to each other and their usefulness for predicting mortality at 1 year are unknown. OBJECTIVE: To assess the relationships between the 6-minute walk test, heart rate variability, and 1-year mortality. METHOD: A sample of 113 patients in advanced stages of heart failure (New York Heart Association Functional Class III-IV, left ventricular ejection < 0.25) were studied. All 6-minute walks took place in an enclosed, level, measured corridor and were supervised by the same nurse. Heart rate variability was measured by using (1) a standard-deviation method and (2) Poincaré plots. Data on RR intervals obtained by using 24-hour Holter monitoring were analyzed. Survival was determined at 1 year after the Holter recording. RESULTS: The results showed no significant associations between the results of the 6-minute walk and the two measures of heart rate variability. The results of the walk were related to 1-year mortality but not to the risk of sudden death. Both measures of heart rate variability had significant associations with 1-year mortality and with sudden death. However, only heart rate variability measured by using Poincaré plots was a predictor of total mortality and risk of sudden death, independent of left ventricular ejection fraction, serum levels of sodium, results of the 6-minute walk test, and the standard-deviation measure of heart rate variability. CONCLUSIONS: Results of the 6-minute walk have poor association with mortality and the two measures of heart rate variability in patients with advanced-stage heart failure and a low ejection fraction. Further studies are needed to determine the optimal clinical usefulness of the 6-minute walk and heart rate variability in patients with advanced-stage heart failure.

Death, Sudden↗
PubMed1997

Heart failure in women.

Although the incidence of heart failure is less in women than in men, prevalence is similar and heart failure is a major cause of morbidity and mortality for women as it is for men. Survival rates are better for women, but women are hospitalized more often for heart failure than men despite being more compliant with medical therapy. Quality of life for women with heart failure may be worse than that in men, with potentially important consequences given the impact of quality of life on mortality in patients with heart failure. Relatively few women are enrolled in heart failure studies and clinical trials. In the major heart failure clinical trials, no study enrolled more than 30% women and few analyzed separately the treatment responses of women and men. Future researches must begin to enroll large numbers of women in heart failure studies and must examine women's unique responses.

Adult↗
PubMed1996

Maximizing therapy in the advanced heart failure patient.

Heart failure is a common clinical syndrome in which left ventricular dysfunction results in vasoconstriction, volume overload, activity intolerance, reduced quality of life, and high mortality. Recognition of the role of neurohormonal activation in the progression of heart failure has led to more effective treatment. Integral to optimal treatment of heart failure is maximization of both pharmacologic and nonpharmacologic therapy. This article presents information important to maximizing both types of therapy in the advanced heart failure patient. The importance of effective patient and family education is emphasized.

Cardiovascular Agents↗
PubMed1996

Comparison of four methods of assessing heart rate variability in patients with heart failure.

BACKGROUND: Heart rate variability reflects autonomic tone and is used to assess progression and prognosis in a variety of illnesses. However, multiple heart rate variability methods exist and are not necessarily equivalent. OBJECTIVES: To compare four methods of heart rate variability in heart failure patients and healthy subjects. METHODS: Twenty-four-hour Holter recordings were obtained in 50 heart failure patients and 50 age- and gender-matched control patients. From these recordings, heart rate variability was assessed by histograms, standard deviation, Poincaré plots, and spectral analysis. RESULTS: For R-R interval histograms, standard deviation, and Poincaré plots, diminished heart rate variability was identified in 65% to 100% of heart failure patients versus 0% to 8% of controls. Agreement among these tests ranged from 69% to 96%. Spectral values varied greatly over the recording period, even in the same subject, possibly because of variations in activity. Only 16% of heart failure patients had spectral values that were identified as abnormal. Agreement between spectral analysis and the other methods ranged between 58% and 67%. CONCLUSIONS: Heart rate variability assessed over a 24-hour period with different techniques yields similar but not identical results. Heart rate variability assessed from spectral analysis of short periods of data varied markedly in a 24-hour period and should not be compared with measures obtained from 24-hour methods. Standardization of subject activity and recording time is necessary for comparison of spectral analysis of brief periods. Further research is required to determine if differences among methods assessing 24-hour heart rate variability yield complementary information.

Arrhythmias, Cardiac↗
PubMed1995

Genital tract abnormalities and female sexual function impairment in systemic sclerosis.

OBJECTIVE: Our purpose was to determine the involvement of the female genital tract and its functional consequences on menstrual and sexual aspects in systemic sclerosis. STUDY DESIGN: Sixty women with systemic sclerosis and 23 age- and disease duration-matched women with either rheumatoid arthritis or systemic lupus erythematosus were surveyed with a comprehensive questionnaire addressing problems before and after disease onset. Fourteen systemic sclerosis patients also had gynecologic evaluations. RESULTS: Vaginal dryness (71%), ulcerations (23%), and dyspareunia (56%) were significantly more frequent in patients with systemic sclerosis after disease onset than before and also in comparison with control subjects. Vaginal tightness and constricted introitus were present in 5 of 60 systemic sclerosis patients. More than half of systemic sclerosis patients reported a decrease in the number (p = 0.04) and intensity (p = 0.02) of orgasms, compared to < 20% of control subjects. The desire and frequency of coitus and the sexual satisfaction index were impaired equally in each group. Skin tightness, reflux-heartburn, and muscle weakness adversely affected sexual relations more in systemic sclerosis than in control subjects. On gynecologic examination 5 of 11 systemic sclerosis patients had small-sized uteri, and 3 of them had early menopause at 29, 38, and 43 years. Seven of 16 (44%) women with systemic sclerosis, compared with 6% of normal women in the United States, attained natural menopause before age 45. CONCLUSIONS: Although impairment in various indexes of sexual function occurs in a number of autoimmune diseases, decreased orgasmic function appears to be limited to systemic sclerosis. Vaginal involvement and other systemic sclerosis-related systemic symptoms adversely influence sexual relations. Menstrual abnormalities, including early menopause, affect many patients. Genital tract involvement occurs in a substantial proportion. Prospective longitudinal studies are warranted.

Adult↗
PubMed1995

Causes of delay in seeking treatment for heart attack symptoms.

With the advent of thrombolytic therapy and other coronary reperfusion strategies, rapid identification and treatment of acute myocardial infarction greatly reduces mortality. Unfortunately, many patients delay seeking medical care and miss the benefits afforded by recent advances in treatment. Studies have shown that the median time from onset of symptoms to seeking care ranges from 2 to 61/2 hours, while optimal benefit is derived during the first hour from symptom onset. The phenomenon of delay by AMI patients and those around them needs to be understood prior to the design of education and counseling strategies to reduce delay. In this article the literature is reviewed and variables that increase patient delay are identified. A theoretical model based on the health belief model, a self regulation model of illness cognition, and interactionist role theory is proposed to explain the response of an individual to the signs and symptoms of acute myocardial infarction. Finally, recommendations are made for future research.

Attitude to Health↗
PubMed1994

Complex heart rate variability and serum norepinephrine levels in patients with advanced heart failure.

OBJECTIVES: This study was designed to examine the relation of the Poincaré plot heart rate variability pattern to sympathetic nervous system activity as assessed by serum norepinephrine. BACKGROUND: Poincaré plots demonstrate a complexity of beat to beat behavior not readily detected by other heart rate variability measures. Previous studies have described two abnormal Poincaré patterns in patients with heart failure: a torpedo pattern with reduced beat to beat variability and a complex pattern with clustering of points. METHODS: To assess the relation of these plots to sympathetic activity, plasma norepinephrine at rest and a standard deviation measure of heart rate variability were analyzed in 21 patients with heart failure (mean left ventricular ejection fraction [+/- SD] 0.22 +/- 0.05). RESULTS: Eleven subjects had a torpedo-shaped and 10 subjects had a complex Poincaré plot pattern. These two groups did not differ significantly in age, functional class, disease etiology, left ventricular ejection fraction, heart rate, ventricular ectopic activity or in a standard deviation measure of heart rate variability. However, patients with a complex Poincaré plot pattern had higher norepinephrine levels (722 +/- 373 pg/ml) than patients with torpedo-shaped plots (309 +/- 134 pg/ml) (p = 0.003). Patients with a complex pattern also had more severe hemodynamic decompensation, as evidenced by their higher levels of pulmonary capillary wedge and mean pulmonary artery pressures and lower values for cardiac index than those of patients with a torpedo-shaped plot. CONCLUSIONS: Complex Poincaré plots are associated with marked sympathetic activation and may provide additional prognostic information and insight into autonomic alterations and sudden cardiac death in patients with heart failure.

Electrocardiography, Ambulatory↗
PubMed1994

Timing of sudden death in patients with heart failure.

OBJECTIVES: The purpose of this study was to determine the timing of sudden death in patients with advanced heart failure. BACKGROUND: The frequency of sudden cardiac death and myocardial infarction is greatest in the morning hours, suggesting that physiologic processes associated with morning activities may trigger these events. In patients with advanced heart failure, a variety of mechanisms may cause sudden death, and the frequency of their occurrence may differ from that in other patient groups, perhaps altering the timing of sudden death in heart failure. METHODS: Deaths among 566 consecutive patients followed up after treatment for advanced heart failure were prospectively categorized as sudden death, death due to heart failure or noncardiac death. For 72 sudden deaths the time of death was determined from witnesses to the event and from death certificates. RESULTS: Sudden death occurred 2.5 times more frequently between 6:01 AM and 12 noon than in the three other 6-h intervals, with 46% of deaths occurring during this period (p < 0.005). The morning peak occurred both in patients with coronary artery disease and in those with nonischemic causes of heart failure. CONCLUSIONS: Despite a variety of potential mechanisms of sudden death and underlying causes of heart disease in patients with heart failure, the 24-h distribution of sudden death in these patients is similar to that observed in other patient groups. Morning surges in sympathetic nervous system activity may promote a variety of sudden death mechanisms, including ischemic and nonischemic arrhythmias.

Adult↗
PubMed1994

Social support and cardiac recovery.

Social support has been implicated as a significant factor in recovery from myocardial infarction and coronary artery bypass surgery. Questions surrounding the role of social support in recovery that this article will answer include the following: How powerful is social support in promoting recovery? Must social support interventions be complex to be effective? What are the effects of problematic social support? How does social support promote recovery? How can nurses improve social support to maximize patient outcomes?

Coronary Disease↗
PubMed1994

The relationship of marital quality and psychosocial adjustment to heart disease.

Psychosocial adjustment to heart disease is variable. Some patients recover from a myocardial infarction or cardiac surgery quickly, return to work and leisure activities, and experience little emotional distress. Others suffer significant problems in psychosocial adaptation. We proposed and tested a theoretical model of adjustment that included the quality of the marital relationship, dysphoria, chronologic age, and time from the cardiac event (myocardial infarction or surgery) to identify the role that these variables play in adjustment. The study was conducted in 198 men diagnosed with coronary heart disease using the following instruments: the Spanier Dyadic Adjustment Scale, the Multiple Affect Adjective Checklist, and the Psychosocial Adjustment to Illness Scale. Data were collected on entry into the study and 3 months later to identify the stability of the relationships over time. The theoretical model was supported. Findings demonstrated that positive psychosocial adjustment to illness is influenced both by the quality of the patient's marriage and dysphoria. The spouse appears to influence psychosocial adjustment in an indirect manner by influencing the patient's experience of emotional distress or dysphoria. Nurses can enhance psychosocial adjustment to coronary heart disease by helping patients and spouses focus on ways to improve the quality of their marriage and by suggesting strategies to improve marital communication and decrease fear and misconceptions related to the illness.

Adult↗
PubMed1994

Is cardiopulmonary resuscitation training deleterious for family members of cardiac patients?

The purpose of the study was to determine the attitudes toward cardiopulmonary resuscitation (CPR) training and subsequent CPR use of 172 CPR-trained family members of cardiac patients. The majority (88.9%) reported positive attitudes. Only 14 (8.1%) reported feeling too responsible for their family member. One hundred and forty-one (81.9%) said that they would perform CPR if required to do so. Family members do not feel unduly burdened by learning CPR, and CPR training should be recommended to families of patients at risk for sudden cardiac death.

Adult↗
PubMed1994

Recurrent ventricular tachycardia.

Recurrent ventricular tachycardia presents nurses with multiple challenges in terms of the knowledge of arrhythmia etiology, treatment, identification of potential problems, and physiologic and psychologic interventions before, during, and after an electrophysiology study. To assist in the understanding of arrhythmia etiology, the predominant electrophysiologic mechanisms for recurrent ventricular tachycardia are discussed. Also discussed are the procedures that can occur during an electrophysiology study and treatment options. Implications for nurses are discussed and include such factors as potential adverse physiologic and psychologic incidents that may be manifested in the pre- or postelectrophysiology study period.

Anti-Arrhythmia Agents↗