Download Uncertainty in Patients Newly Diagnosed with Atrial Fibrillation

Journal of Korean Academy of Nursing (2002) Vol. 32, No. 7
Uncertainty in Patients Newly Diagnosed
with Atrial Fibrillation
Younhee Kang, RN, MSN-ANP, PhD
Purpose of the Study. Atrial fibrillation is the most common sustained cardiac rhythm disturbance encountered
in clinical practice. In contrast to its high prevalence and the associated high number of hospital admissions,
there is a paucity of published studies that have evaluated the perspective of patients with atrial fibrillation
or patients’perceptions or responses to diagnosis, treatment, or prognosis of atrial fibrillation in health care
literature and clinical studies. This study aimed to explore uncertainty in diagnosis, treatment, and prognosis
of atrial fibrillation.
Methods. This study employed a descriptive cross-sectional survey design using a face-to-face interview method
to explore uncertainty. Patients with atrial fibrillation confirmed by 12-lead ECG were interviewed.
Uncertainty was measured by the Mishel Uncertainty in Illness Scale-Community Form (MUIS-C), and the
data collected were analyzed by the Statistical Package for Social Science software program.
Results. A total of 81 subjects were included in this study and their mean score of uncertainty was 62.60 with the
standard deviation of 10.81. Uncertainty in patients with atrial fibrillation was higher than that reported in
other disease populations such as bowel resection surgery, breast cancer, myocardial infarction, and so
forth. However, it was lower than the level of uncertainty in patients with cardiac arrest and HIV disease.
Conclusion. From the findings of the present study, it was demonstrated that uncertainty existed in patients with
atrial fibrillation, and this was considered to be part of patients’responses to atrial fibrillation. In terms of
nursing practice and nursing research, uncertainty was explored and described as one of the most relevant
phenomena in patients newly diagnosed with atrial fibrillation.
Key Words: Uncertainty, Atrial fibrillation
INTRODUCTION
1. Background and significance
Atrial fibrillation is the most common sustained cardiac rhythm disturbance encountered in clinical practice.
The overall prevalence of atrial fibrillation in the United
States is 0.4% of the general population (Coumel, 1996)
and nearly 9% in elderly patients (Jung & Luderitz,
1998). Furthermore, the number of hospital admissions
for atrial fibrillation is more than 1 million each year, an
incidence higher than that of any other cardiac arrhythmia in the United States (Tanigawa et al., 1991; Bialy,
Lehmann, & Schumacher, 1992). In addition to its high
prevalence and the associated high number of hospital
admissions, the presence of atrial fibrillation with other
diseases increases their mortality rate by 200%. The
consequences of atrial fibrillation, such as systemic em-
1. Full-time lecturer, Department of Nursing, College of Medicine, Kyungpook National University
Corresponding author: Younhee Kang, RN, MSN-ANP, PhD, Department of Nursing, College of Medicine, Kyungpook National University,
101 Dong In, 2-Ga, Chung-gu, Daegu 700-422, Korea
Tel: 82-53-420-6983 Fax: 82-53-421-6383 E-mail: [email protected]
This manuscript is the part of doctoral dissertation.
This study was financially supported by the Alumni Association of the Frances Payne Bolton School of Nursing, Sigma Theta Tau International, Alpha Mu
Chapter, and Dr. Susie Kim’
s Dissertation Award.
Received May 14, 2002 ; Accepted December 3, 2002
Kang Uncertainty in Patients Newly Diagnosed with Atrial Fibrillation 961
bolism, stroke, hemodynamic dysfunction, and cardiomyopathy, are associated with significant mortality
(Kannel, Abbott, Savage, & McNamara, 1982; Golzari,
Cebul, & Bahler, 1996).
Despite the significant impact of atrial fibrillation on
health care and on the population, it has been generally
considered a benign disorder in clinical practice and is
often not seen as being as important as ventricular arrhythmias in clinical care nor in health care research.
Morbidity and mortality rates of atrial fibrillation have
been reported in the literature. However, few studies
document the actual impact of atrial fibrillation on the
patient. Thus, there is a paucity of published studies that
have evaluated the perspective of patients with atrial fibrillation or patients’ perceptions or responses to diagnosis, treatment, or prognosis of atrial fibrillation in health
care literature and clinical studies.
Among diverse nursing phenomena, uncertainty is a
relevant phenomenon in individuals with atrial fibrillation since the nature of the course of atrial fibrillation
might be likely to be more probabilistic than any other
illness. A number of research studies regarding pathophysiology and treatment of atrial fibrillation have been
conducted. There is, however, no one accepted approach
to the management of atrial fibrillation although pharmacological and nonpharmacological therapies have
been adopted (Prystowsky et al., 1996; Grant, 1998;
Waktare & Camm, 1988). In order to control ventricular
rate, and to restore and maintain sinus rhythm, the combination of electrical cardioversion, antiarrhythmic medication, and AV node ablation have been applied.
However, the recurrence rate of atrial fibrillation is very
high (Coplen, Antman, Berlin, Hewitt, & Chalmers,
1990), and the adverse effects (e.g. psychosis, blurred vision, liver toxicity, life-threatening ventricular tachycardia, etc.) from antiarrhythmic medication are seriously
harmful to patients, thus long-term uses of these drugs
are avoided (Prystowsky et al., 1996; Harvey &
Champe, 1992). Furthermore, to prevent thrombo-embolism and subsequent stroke, anticoagulation therapy
using warfarin is required regardless of etiology. This
therapy also has significant side effects and requires frequent blooding drawings and clinic visits. Throughout
the above course of treatment and management of atrial
fibrillation, patients may get confused, and may not be
able to predict and make decisions about their future relating the illness. This lack of predictability of events or
situations associated with atrial fibrillation is related to
the phenomenon of uncertainty, and it may create stressful situations for patients.
2. Purpose of the Study
This study aimed to explore uncertainty in diagnosis,
treatment, and prognosis of atrial fibrillation.
3. Definitions of Terms
Atrial fibrillation was conceptually defined as a type of
cardiac rhythm disturbance, consisting of electrophysiologically rapid uncoordinated generation of electrical
multifocal impulses by atria at a rate of 300 to 500/
minute (Barker, Burton, & Zieve, 1994; Kelley, 1997).
This definition was operationalized by 12-lead electrocardiogram.
Uncertainty was a cognitive state that occurs in situations in which the decision maker is unable to assign definite values to events or objects and / or is unable to predict outcomes accurately because the cues are vague, inadequate, unfamiliar, contradictory, numerous, or lacking information (Budner, 1962; Mishel, 1984). For this
study, the operational definition of uncertainty was a
subject’s rating of Mishel Uncertainty in Illness ScaleCommunity form (MUIS-C).
METHODS
1. Design
This study employed a descriptive cross-sectional survey design using a face-to-face interview method to explore uncertainty. Because the phenomenon of uncertainty in patients newly diagnosed with atrial fibrillation
has not been studied, a descriptive design is appropriate.
In addition, the survey method using personal interviews
was adopted since this approach was expected to result
in a higher response rate than questionnaires.
2. Setting
The setting for the study was the cardiology outpatient
clinic and the outpatient clinic for anticoagulation therapy in MetroHealth Medical Center and University
Hospitals of Cleveland, Cleveland, Ohio, USA. At the
beginning of data collection, subjects were recruited
from only MetroHealth Medical Center. The reason for
choosing just one hospital for the data collection was
that, since the same patient care protocol is used, the effect of health care providers on uncertainty could be
controlled. According to Mishel’s model of uncertainty
962 Journal of Korean Academy of Nursing Vol. 32, No. 7
in illness (1988), the credible authority from nurses or
physicians promotes the formulation of the stimuli frame
by providing information on the causes and consequences of the symptoms so that it reduces uncertainty
indirectly. Therefore, subject recruitment from one hospital can minimize the extraneous effect of credible authority from health care providers on uncertainty; collecting the data within a more homogenous sample from
one site rather than within a heterogeneous sample from
diverse sites thus equalized the effect of authority from
the health care providers. However, there were inadequate numbers of subjects available within a given time
of period, and therefore University Hospitals of
Cleveland was added as another recruitment site in the
middle of data collection. Hence, health care provider
was considered as a covariate for uncertainty and was
statistically controlled.
3. Sample
A convenience sampling method was used to obtain
subjects for this study. The criteria for inclusion in the
study and their rationale are as follows: first, the subject
must have been newly diagnosed with atrial fibrillation
within 6 months prior to data collection. The reason for
including only patients with acute atrial fibrillation was
that the degree of uncertainty may be different by the
duration of diagnosis (Mishel, 1981), and at the time of
diagnosis and start of treatment, its degree may be maximum. Secondly, the subject must be able to speak and
read English in order to understand the study questionnaires and to answer the questions. Thirdly, the subject
must be an adult, age 18 or older. Patients who meet
these inclusion criteria were screened for the following
exclusion criteria. First, anyone who is newly diagnosed
with any disease other than atrial fibrillation within the
previous 3 months. Because being newly diagnosed with
other diseases may affect the patient’s perceived uncertainty regarding diagnosis, treatment, and prognosis of
atrial fibrillation, those newly diagnosed with any other
disease will be excluded from the study. Lastly, anyone
who has terminal illness which leads to death within 1
year since there is no situation more serious and uncertain than death.
4. Instrument
Uncertainty was measured by the Mishel Uncertainty
in Illness Scale-Community Form (MUIS-C). The MUISC measures uni-dimensional uncertainty in illness within
the non-hospitalized community population; thus it provides only a total scale score (Mishel, 1997). The MUISC consists of 23 items, and each item on the MUIS-C
represents uncertainty in terms of a 5 point Likert-format scale ranging from “strongly agree” to “strongly disagree.” A possible score range of uncertainty on the
MUIS-C is from 23 to 115 with a midrange score of 69
(Mishel, 1997), and the higher the score on the MUIS-C,
the higher the perceived uncertainty. The mean uncertainty scores in 18 samples was reported as ranging from
42.4 to 85.5 (Mishel, 1997). In the previous studies, the
reliability for the MUIS-C has been shown to be in the
moderate to high range (α=.74 to .92) (Mishel, 1997). In
the present study, the reliability coefficient for the
MUIS-C was .86. Validity of MUIS has been demonstrated by Misel’s finding that the scale discriminated significantly among medical, surgical, and diagnostic patient
populations as predicted (Mishel, 1981). The construct
validity was also supported by items clustering into two
factors (multi-attributed ambiguity & unpredictability)
consistent with theoretical predictions (Mishel, 1981;
Mishel, 1984).
5. Data collection procedure
The subjects for this study were recruited from
MetroHealth Medical Center and University Hospitals
of Cleveland by the investigator. The investigator identified patients newly diagnosed with atrial fibrillation by
daily visiting or by calling nurses in the outpatient clinic
for anticoagulation therapy or in the cardiology outpatient clinic. The investigator reviewed patients’ charts to
confirm subject eligibility based on subject inclusion and
exclusion criteria. Once subject eligibility was determined, the subjects were approached by the investigator
on the day of the subject’s clinic appointment. If subjects
were interested in participating in the study, they were
interviewed by the investigator.
6. Human subjects protection
The present study was approved by the Frances Payne
Bolton School of Nursing Committee on Human
Subjects Review board and by the review board for protection of human subjects of MetroHealth Medical
Center and University Hospitals of Cleveland. Potential
subjects were given both verbal information and a written summary of the study before being asked to participate in the study. If a subject agreed to participate in the
study, the subject read the informed consent form, and
Kang Uncertainty in Patients Newly Diagnosed with Atrial Fibrillation 963
the subject was asked to sign the consent form.
7. Data analysis
The data was analyzed by the Statistical Package for
Social Science software program. Univariate descriptive
statistics were examined including the frequency distribution, the central tendency, and the dispersion of the
scores in order to identify missing data, outliers, and errors in data entry. In order to control the effect of time
since diagnosis and health care provider respectively on
uncertainty, t-test was utilized.
RESULTS
1. Characteristics of Sample
The demographic characteristics of the sample for the
present study are shown on Table 1, including age, gender, race, marital status, education, period since diagnosed, and health care provider.
Table 1. Demographic characteristics of sample (N=81)
Characteristics
N (%)
Age (years)
25-49
50-59
60-69
70-79
80-89
07 (8.6)0
14 (17.3)
23 (28.4)
26 (32.1)
11 (13.6)
Range
25-88
2. Uncertainty
As shown in Table 2, the mean of uncertainty in the
sample was 62.60 with the standard deviation of 10.81.
Subjects had moderate uncertainty.
Gender
Male
Female
41 (50.6)
40 (49.4)
White
Black
72 (88.9)
09 (11.1)
A total of 81 subjects were recruited for this study.
Their mean age was 67.3 years old, and three-fourths
(74.1%) were over age 60. Subjects were equally distributed by gender, and the majority (88.9%) were
Caucasian. Most subjects (81.5%) were diagnosed with
atrial fibrillation within 3 months previous to data collection. Three-fourths (76.5%) of the sample received
their health care from MetroHealth Medical Center, and
the rest from University Hospitals of Cleveland. Because
time since diagnosis and health care provider could respectively influence uncertainty, differences between
groups in time since diagnosis (within 3 months and
more than 3 months) and health care provider
(MetroHealth Medical Center and University Hospitals
of Cleveland) were examined. There was no significant
difference in uncertainty between those with a diagnosis
of 3 months or less (M=62.88, SD=10.85) and those
with a diagnosis of more than 3 months (M=61.40,
SD=10.91). However, there was a significant difference
in uncertainty between those with MetroHealth Medical
Center (M=64.65, SD=10.95) and those with University
Hospitals of Cleveland (M=55.95, SD=7.21) as their
health care provider.
DISCUSSION
Race
Marital Status
Single
Married
Widow
Divorced
11 (13.6)
35 (43.2)
22 (27.2)
13 (16)0.
Period since Diagnosis
Within 3 months
More than 3 months
66 (81.5)
15 (18.5)
Health Care Provider
MetroHealth Medical Center
University Hospital
62 (76.5)
19 (23.5)
Table 2. Descriptive statistics for uncertainty (N=81)
Concept (# of items) Mean (SD) MinimumMaximum
Possible
Range
Uncertainty (23)
23-115
62.60 (10.81)
46
87
From the findings of the present study, it was demonstrated that uncertainty existed in patients with atrial fibrillation, and this was considered to be part of patients’
responses to atrial fibrillation. Uncertainty in patients
with atrial fibrillation (M=62.6, range 46-87) was higher than that reported in other disease populations such
as bowel resection surgery (M=42.4), breast cancer
(M=33.7), coronary artery bypass surgery (M=58.8), myocardial infarction (M=51.5), and renal disease
(M=52.3). However, it was lower than the level of uncertainty in patients with cardiac arrest (M=72.6), epilepsy
(M=74.8), lupus (M=73.2), and HIV disease (M=63.7).
The magnitude of uncertainty perceived by atrial fibrillation patients was moderately high compared to other
clinical populations. This higher uncertainty may be associated with the public’s ignorance about atrial fibrillation and the nature of the course of atrial fibrillation.
964 Journal of Korean Academy of Nursing Vol. 32, No. 7
Atrial fibrillation has been less understood by the public
compared to other diseases, including coronary heart
disease, various cancers, and surgeries, since it is not
physically seen on pictures by diagnostic tests but is associated with the complicated electrical movement of
heart. This unclear view of atrial fibrillation may create
the uncertainty documented in this study.
The treatments of atrial fibrillation are very complicated and are individualized for each patient depending on
underlying clinical circumstances. There is no one accepted approach to the management of atrial fibrillation
although pharmacological and nonpharmacological therapies have been adopted, including antiarrhythmic drug
therapy, anticoagulation therapy, electric cardioversion,
and AV node ablation (Prystowsky et al., 1996; Grant,
1998; Waktare & Camm, 1988). The availability of these
diverse options for the treatment and management of
atrial fibrillation may contribute to the patients’ uncertainty. In addition, the recurrence rate of atrial fibrillation is very high and three-fourths of patients revert to
atrial fibrillation after cardioversion if not treated with
the usual antiarrhythmic agents (Coplen, Antman,
Berlin, Hewitt, & Chalmers, 1990), and reliable predictors for recurrence are unknown. Therefore, patients are
likely to be confused and uncertain about complex treatments and prognosis, and they may have varied expectations of treatment and prognosis after diagnosis. A clear
idea of what will happen may not be possible and patients, therefore, may not be able to make decisions
about a course of action (Hilton, 1992). This lack of predictability of events or situations associated with atrial
fibrillation is related to the uncertainty, and it may create
stressful situations for patients. It has been well documented that uncertainty may cause a great deal of psychosocial stress and enhance the personal and family
hardship (Strauss et al., 1984; Lazarus & Folkman,
1984; Mishel, 1981; Shalit, 1977; Suls & Mullen, 1981).
Increased uncertainty has been associated with increased stress (Mishel, 1981; Mishel, 1984; Davis, 1990),
more psychological mood disturbance (Christman et al.,
1988; Christman, 1990; Jessup & Stein, 1985; Mishel &
Braden, 1987; Mishel, Hostetter, King, & Graham, 1984;
McCain & Cella, 1995; Mullins et al., 1995; Wineman,
Schwetz, Goodkin, & Rudick, 1996), increased anxiety
(Warrington & Gottlieb, 1987; Webster & Christman,
1988; Wong & Bramwell, 1992), lower level of life quality (Carroll, Hamilton, & McGovern, 1999), reduced coping effectiveness (Bennett, 1993), and perception of di-
minished or lower health status (Carroll, Hamilton, &
McGovern, 1999). Therefore, uncertainty in illness has
been identified as the single greatest source of psychosocial stress to patients (Kroocher, 1985).
Consequently, there was a reasonable basis for hypothesizing that uncertainty was a relevant phenomenon to
atrial fibrillation patients, suggesting that more attention
should be given to the atrial fibrillation population in order to intervene in uncertainty and to produce better
outcomes. Despite the theoretical relevance of uncertainty to atrial fibrillation, until recently little was known
about the population with atrial fibrillation because atrial fibrillation was regarded as a rather trivial disease,
compared with other life-threatening diseases, such as
coronary heart disease, congestive or hypertrophic cardiomyopathy, and mitral valvular diseases. Furthermore,
the lack of information regarding the electrocardiac
pathophysiology of atrial fibrillation has aggravated the
nonchalance towards atrial fibrillation. Thus, no work
has been done related to the patient’s perspective of atrial fibrillation so far. This study was the first trial to explore patients’ responses to atrial fibrillation and uncertainty. As proposed, this study demonstrated that uncertainty was relevant and significant as a component of patients’ responses to atrial fibrillation.
CONDUSION, LIMITATION & SUGGESTION
The present study aimed to explore uncertainty in diagnosis, treatment, and prognosis of atrial fibrillation.
The finding of this study indicated that uncertainty was
moderately high in atrial fibrillation patients compared
to other clinical populations. The present study was the
first trial to explore the patients’ perspective of atrial fibrillation, and the finding provided clinical nurses with information that helps nurses to understand individuals
with atrial fibrillation and identify nursing problems
nurses need to assess and to address. Furthermore, information on persons’ perception of atrial fibrillation guides
other future nursing research studies to examine and
evaluate nursing interventions for individuals with atrial
fibrillation. In addition, findings from these studies will
substantially contribute to the body of nursing knowledge by expanding the scope of the nursing discipline
through identifying new phenomena or concepts.
Accordingly, these studies will help fill the gaps in nursing knowledge between what we have known and what
we do not know about patients with atrial fibrillation.
Kang Uncertainty in Patients Newly Diagnosed with Atrial Fibrillation 965
In the present study, there were two limitations that
had to be recognized. First, this study utilized a convenience sampling method. Secondly, subjects were predominantly Caucasian, and African-American patients
were underrepresented. Both convenience sampling
method and demographic characteristic of the sample
limited the ability to generalize the results of this study
beyond the sample. Thus, the results of this study should
be interpreted with caution because of the non-random
sampling technique and demographic characteristics of
the sample.
Lastly, the future studies that confirm the finding related to the level of uncertainty in the population of atrial
fibrillation patients through replication were recommended. Moreover, the research studies that examine
the factors influencing uncertainty including personality
dispositions (health locus of control, learned resourcefulness, a sense of mastery, and so forth) and that determine a consequence of uncertainty were needed.
References
Barker, L. R., Burton, J. R., & Zieve, P. D. (1994). Principles of ambulatory medicine (4th ed.). Philadelphia: Williams & Wilkins.
Bialy, D., Lehmann, M. H., & Schumacher, D. N. (1992).
Hospitalization for arrhythmia in the United States:
Importance of atrial fibrillation [abstract]. Journal of American
College of Cardiology, 19, 41.
Budner, S. (1962). Intolerance of ambiguity as a personality variable. Journal of Personality, 30, 29-50.
Carroll, D. L., Hamilton, G. A., & McGovern, B. A. (1999).
Changes in health status and quality of life and
the impact of uncertainty in patients who survive life-threatening
arrhythmias. Heart & Lung, 28(4), 251-260.
Christman, N. J. (1990). Uncertainty and adjustment during radiotherapy. Nursing Research, 39(1), 17-20.
Christman, N. J., McConnell, E. A., Pfeiffer, C., Webster, K. K.,
Schmitt, M., & Ries, J. (1988). Uncertainty, coping, and distress following myocardial infarction: transition from hospital
to home. Research in Nursing and Health, 11(2), 71-82.
Coplen, S. E., Antman, E. M., Berlin, J. A., Hewitt, P., & Chalmers,
T. C. (1990). Efficacy and safety of quinidine therapy for maintenance of sinus rhythm after cardioversion: A meta-analysis of
randonmized control trials. Circulation, 82, 1106-1116.
Coumel, P. (1996). Autonomic influences in atrial tachyarrhythmias. Journal of Cardiovascular Electrophysiology, 7, 9991007.
Davis, L. L. (1990). Illness uncertainty, social support, and stress in
recovering individuals and family care givers. Applied Nursing
Research, 3(2), 69-71.
Golzari, H., Cebul, R. D., & Bahler, R. C. (1996). Atrial fibrillation:
Restoration and maintenance of sinus rhythm and indicators
for anticoagulation therapy. Annals of Internal Medicine,
125(4), 311-323.
Grant, A. O. (1998). Mechanisms of atrial fibrillation and action of
drugs used in its management. American Journal of
Cardiology, 82, 43N-49N.
Harvey, R. A. & Champe, P. C. (1992). Pharmacology: Lippincott’s
illustrated review. Philadelphia: J. B. Lippincott Company.
Hilton, B. A. (1992). Perceptions of uncertainty: its relevance to
life-threatening and chronic illness. Critical Care Nurse, 12(1),
70-73.
Jessup, D. J., & Stein, R. E. K. (1985). Uncertainty and its relation
to the psychological and social correlates of chronic illness in
children. Social Science and Medicine, 20(10), 993-999.
Jung, W., & Luderitz, B. (1998). Quality of life in patients with atrial fibrillation. Journal of Cardiovascular Electrophysiology, 9,
S177-S187.
Kannel, W. B., Abbott, R. D., Savage, D. D., & McNamara, P. M.
(1982). Epidemiologic features of chronic atrial fibrillation: The
Framingham study. New England Journal of Medicine, 306,
1018-1022.
Kelley, W. N. (1997). Textbook of Internal Medicine (3rd ed.).
Philadelphia: Lippincott-Raven Publishers.
Kroocher, G. P. (1985). Psychosocial care of the child cured of cancer. Pediatric Nursing, 11, 91-93.
Lazarus, R. S., & Folkman, S. (1984). Stress, appraisal, and coping.
New York: Springer.
McCain, N. L., & Cella, D. F. (1995). Correlates of stress in HIV disease. Western Journal of Nursing Research, 17, 141-155.
Mishel, M. H. (1981). The measurement of uncertainty in illness.
Nursing Research, 30(5), 258-263.
Mishel, M. H. (1984). Perceived uncertainty and stress in illness.
Research in Nursing and Health, 7, 163-171.
Mishel, M. H. (1988). Uncertainty in illness. Image: Journal of
Nursing Scholarship, 20(4), 225-232.
Mishel, M. H. (1997). Uncertainty in illness scales manual. Chapel
Hill: The University of North Carolina.
Mishel, M. H., & Braden, C. J. (1987). Uncertainty: A mediator between support and adjustment. Western Journal of Nursing
Research, 9(1), 43-57.
Mishel, M. H., Hostetter, T., King, B., & Graham, V. (1984).
Predictors of psychosocial adjustment in patients newly diagnosed with gynecological cancer. Cancer Nursing, 7(4), 291299.
Mullins, L. L., Cheney, J. M., Hartman, V. L., Albin, K., Miles, B., &
Roberson, S. (1995). Cognitive and affective features of postpolio syndrome: illness uncertainty, attributional style, and
adaptation. International Journal of Rehabilitation and
Health, 1, 211-222.
Prystowsky, E. N., Benson, D. W., Fuster, V., Hart, R. G., Kay, N.,
Myerburg, R. J., Naccarelli, G. V., & Wyse, G. (1996).
Management of patients with atrial fibrillation: A statement for
healthcare professionals from the subcommittee on electrocardiography and electrophysiology, American Heart Association.
Circulation, 93, 1262-1277.
Shalit, B. (1977). Structural ambiguity and limits to coping. Journal
of Human Stress, 3(4), 32-45.
Strauss, A. L., Corbin, J., Fagerhaugh, S., Glaser, B., Maines, D.,
Suczek, B., & Wiener, C. (1984). Chronic illness and the quality of life (2nd ed.). St. Louis: C. V. Mosby.
Suls, J., & Mullen, B. (1981). Life events, perceived control and illness: the role of uncertainty. Journal of Human Stress, 7(2),
30-34.
Tanigawa, M., Fukatani, M., Konoe, A., Isomoto, S., Kadena, M., &
Hashiba, K. (1991). Prolonged and fractionated right atrial
966 Journal of Korean Academy of Nursing Vol. 32, No. 7
electrograms during sinus rhythm in patients with paroxysmal
atrial fibrillation and sick sinus node syndrome. Journal of
American College of Cardiology, 17, 403-408.
Waktare, J. & Camm, J. (1988). Acute treatment of atrial fibrillation: Why and When to maintain sinus rhythm. American
Journal of Cardiology, 81(5A), 3C-15C.
Warrington, K., & Gottlieb, L. (1987). Uncertainty and anxiety of
hysterectomy patients during hospitalization. Nursing Papers,
19(1), 59-73.
Webster, K. K., & Christman, N. J. (1988). Perceived uncertainty
and coping post myocardial infarction. Western Journal of
Nursing Research, 10(4), 384-400.
Wineman, N. M., Schwetz, K. M., Goodkin, D. E., & Rudick, R. A.
(1996). Relationships among illness uncertainty, stress, coping,
and emotional well-being at entry into a clinical drug trial.
Applied Nursing Research, 9, 53-60.
Wong, C. A., & Bramwell, L. (1992). Uncertainty and anxiety aftermastectomy for breast cancer. Cancer Nursing, 15(5), 363-371.