Q J Med 2003; 96: 115-123
© 2003 Association of Physicians
Characteristics of patients presenting to a cardiac clinic with palpitation
From the University of Oxford Department of Psychiatry, Warneford Hospital, Oxford, and 1 Department of Cardiology, Northampton General Hospital, Cliftonville, Northampton, UK
Received 26 March 2002 Accepted for publication 29 October 2002.
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Background: Palpitation is a very common presenting symptom in primary care and in cardiac clinics, associated with marked disability. Although serious arrhythmias are uncommon causes, treatment of persistent palpitation is difficult.
Aim: To describe the cardiological, behavioural and psychological characteristics of consecutive patients presenting to a cardiac clinic with the main complaint of palpitation.
Design: Prospective evaluation of consecutive out-patients.
Methods: Participants were 184 consecutive patients with the complaint of palpitation referred to an out-patient cardiac clinic. Three assessments were used. Three to four weeks prior to clinic attendance, measures of symptoms, distress and disability were gathered, and a heart rate perception test was conducted. At the out-patient clinic, a routine clinical assessment was made. Three months later, patients received a questionnaire which included baseline measures of symptoms, distress and disability.
Results: Palpitation was associated with arrhythmias in 62 patients (34%), extrasystoles in 75 patients (41%) and awareness of sinus rhythm in 47 patients (26%). Distress and disability were common and persistent. There were significant differences in the characteristics of the three groups.
Discussion: Most patients presenting to secondary care with palpitation do not have serious underlying cardiovascular conditions. Concurrent psychological problems are common and persistent. Aetiology may be seen as an interaction of pathology, awareness of normal physiology, and psychological variables. Few patients require specialist cardiological treatment, but simple reassurance is of limited effectiveness. A stepped care approach may improve outcomes and needs rigorous evaluation.
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Introduction |
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Palpitation, the uncomfortable awareness of a beating heart, is a normal experience. A recent review concluded that ‘Palpitations are one of the most common problems of outpatients who present to internists and cardiologists. Although usually benign, they are occasionally a manifestation of potentially life-threatening conditions. The physician's fear of missing a treatable condition may lead to the inappropriate use of expensive tests with little diagnostic and therapeutic value.’1 Research with patients with palpitation undergoing 24-h electrocardiography (ECG) recording or using event recorders has concluded that at least half do not have clinically significant arrhythmias.2
However, symptoms and disability tend to persist, whether or not arrhythmias are identified, in both primary3 and secondary care.2,4–7 Research has focused on the small minority with serious arrhythmias who require specialist treatment. Much less is known about the much greater number of consulters who are suffering from either medically minor arrhythmias or benign palpitation (palpitation due to awareness of extrasystoles or sinus rhythm). These patients are, however, known to be difficult to treat.1
We aimed to determine the characteristics of consecutive referrals with the presenting complaint of palpitation from primary care to a cardiac clinic, and to draw conclusions about classification and treatment needs. This clinic served a geographical health area, and followed widely used clinical procedures.1 A companion paper8 has considered other aims relating to heart rate perception and to some specific psychological issues.
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Study population
Consecutive referrals for the assessment of palpitation to the cardiac clinics at Northampton General Hospital, UK during a 12-month period were asked if they would be willing to participate. Ethical approval was granted by Northampton Medical Research & Ethics Committee
Assessment
Initial assessment
Measures at a research assessment 3–4 weeks prior to the out-patient appointment included: self-report questionnaire and semi-structured interview, to determine details of palpitation and other symptoms, previous consultation, disability, beliefs about cause, and health anxiety; Structured Clinical Interview for DSM-IV (anxiety disorders and hypochondriasis);9 and Beck Depression Inventory.10 In addition, all patients took part in a standardized heart rate perception test,8,11 which assessed the subject's ability to estimate heart rate over a defined period. During each test, subjects were instructed to silently count their heartbeats during signalled intervals of 25, 35 and 45 s, without taking their pulse or using other strategies such as holding their breath. Inaccuracy of heart rate perception was defined as the absolute difference between the actual number of heartbeats and counted heartbeats, divided by actual heartbeats, and expressed as a percentage. Most general population subjects have inaccurate heart rate perception. Further details of the test are provided in a companion paper.8
Out-patient clinic assessment
Patients underwent routine outpatient clinic assessment. The assessment consisted of interview, physical examination and interpretation of resting ECG by a cardiologist according to generally accepted clinical principles.1 Ambulatory ECG was performed, unless (a) a previous ECG diagnosis of cause of palpitation had been made; (b) typical palpitation had occurred during the recording of a resting ECG; (c) episodes of palpitation were so infrequent as to make ECG capture unlikely (e.g. less than once every two or three months); or (d) the history was typical of extrasystoles (awareness of a momentary pause in the heart beat followed by a forceful beat) and of no other arrhythmia. Further investigations were performed if clinically indicated, at the discretion of the cardiologist.
Clinical data and investigations were reviewed by one cardiologist (DS) who assigned patients to one of three diagnostic groups:
- Palpitation due to arrhythmia. Definite arrhythmia was diagnosed when there was ECG confirmation of arrhythmia at the time of symptoms. Probable arrhythmia was diagnosed when there was a history of one or more episodes of rapid palpitation of sudden onset and offset, but without ECG recording during symptoms.
- Palpitation due to awareness of sinus rhythm. This was diagnosed when either (i) ECG at the time of symptoms showed normal sinus rhythm or sinus tachycardia, or (ii) when the history was of awareness of forceful regular beating of the heart, at a rate less than 140/min, not of sudden onset or offset, and without other clinical or ECG features to indicate underlying cardiac disorder.
- Palpitation due to extrasystoles. This was diagnosed when there was either (i) ECG confirmation of atrial or ventricular extrasystoles at the time of symptoms or (ii) a history typical of extrasystoles.
Three-month follow-up
All patients were asked to complete a self-report questionnaire at three months which included a global measure of improvement, and other questions about symptoms and disability.
Statistical analysis
Statistical analysis was conducted using SPSS for Windows version 10 and Confidence Interval Analysis version 1.2. For each diagnostic group, proportions and their 95%CIs were calculated for dichotomous variables. For continuous variables, the mean and SD or median and IQR were calculated, depending upon the normality of the distribution. Comparisons between the three diagnostic groups for dichotomous variables were performed with 
2-tests. Differences significant at the 5% level were followed up with separate 2-tests comparing pairs of the three groups. Comparisons between the three groups for continuous variables were performed with analysis of variance (ANOVA) if the distribution was normal, with Kruskal-Wallis tests if the distribution was not normal. Differences significant at the 5% level were followed up by comparing pairs of the three groups with t-tests or pair-wise Mann-Whitney U-tests, respectively. All significance levels were two-tailed.
Patients with benign palpitation who had taken part in the treatment arm, rather than the control arm, of a randomized controlled trial (RCT) of a brief psychological treatment12 were excluded from the analysis of follow-up data. Comparisons of outcome at three months between the three diagnostic groups were performed with 2-tests.
Logistic regression analysis was used to test how well the variables assessed in the study distinguished (a) between patients with arrhythmia and those who were aware of sinus rhythm, and (b) between patients with arrhythmia and those with benign palpitations. Variables which showed significant differences between the groups in the present findings or the companion study8 were entered stepwise. Categorical variables were managed by creating dummy variables. Those variables which made a significant contribution are reported, as is the initial and model 2, the statistical significance of the contribution of this model, and the proportion of patients correctly classified by the model.
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Of 193 consecutive patients referred by general practitioners as having the principal complaint of palpitation, nine were excluded (5 did not attend a cardiac clinic, 2 had neurological symptoms at clinic assessment, and 2 had chest pain rather than palpitation as the main clinical problem). The remaining 184 patients completed the initial assessment and the clinic assessment. Ninety-three patients (50%) received ambulatory ECG using a 24-h continuous (Holter) ECG recorder and/or an intermittent patient-activated ECG event recorder. Eight (4%) also received exercise ECG. Clinical characteristics including disability are summarized in Tables 1
and 2, heart rate perception assessment and psychological assessment in Table 3, and cardiac care in Table 4.
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Cardiological diagnosis
Palpitation due to arrhythmias
Arrhythmias (definite and probable) were detected in 62 (33%) patients. Definite arrhythmias included supraventricular tachycardia (n=16), paroxysmal atrial fibrillation (n=13), non-sustained ventricular tachycardia (n=2), and exercise-induced fascicular ventricular tachycardia (confirmed at electrophysiological study) (n=1). There were no differences between the assessed characteristics of those diagnosed as supraventricular tachycardia and atrial fibrillation. There were no significant differences between patients with definite (n=32) or probable (n=30) arrhythmia with regards to age, gender, associated cardiac disorder, heart rate perception, heart symptoms during the perception test, psychological status or treatment. The groups of patients with definite and probable arrhythmia were therefore combined for subsequent analyses.
Patients with arrhythmias had longer histories than patients with extrasystoles or awareness of sinus rhythm. However, they were less likely to have records of previous non-specific physical symptoms in their medical notes, and suffered less from anxiety and depression (Tables 1
and 3). Even so, their distress was significant, with over one quarter suffering from panic attacks, and one in ten suffering from a depressive illness. Interference with work and with family life was lower than in the sinus rhythm group, but almost half of those with arrhythmia were disabled by palpitation.
There were differences between the three groups in the accuracy with which they perceived heart rate, but these were not significant (Table 3). However, patients with arrhythmia were significantly more likely to perceive their heartbeats accurately than the awareness of sinus rhythm group (28% vs. 11%, 2=4.38, df=1, p=0.036). Furthermore, there were significant differences between the three groups in the presence of cardiac symptoms during the heart rate test (Table 3), with arrhythmia patients being least likely and sinus rhythm patients most likely to experience symptoms.
Palpitation due to awareness of sinus rhythm
There were 47 patients (26%) with awareness of sinus rhythm. Their characteristics are described in Tables 1 and 3. They were significantly more likely to be women than those with palpitation due to arrhythmias (79% vs. 53%, 2=7.6, df=1, p=0.006), and were significantly younger than those with extrasystoles.
The sinus rhythm group had the highest psychological morbidity of the three groups. Panic attacks were significantly more prevalent than in the arrhythmia group (47% vs. 27%, 2=4.26, df=1, p=0.04). Sinus rhythm patients were also more frequently depressed than patients with arrhythmia (23% vs. 10%, 2 3.827, df=1, p=0.05) and more worried about their health in general than patients with arrhythmia or extrasystoles (ANOVA F=3.06, df=175, p=0.049).
Palpitation due to extrasystoles
There were 75 patients (41%) with palpitation due to extrasystoles. They were generally intermediate in their characteristics between those with arrhythmias and those with awareness of sinus rhythm (see Tables 1 and 3). They were significantly more likely than the other groups to experience palpitation as a missed beat (extrasystoles 21% vs. arrhythmia 4% vs. sinus rhythm 1%, 2=9.59, df=2, p=0.008). Psychiatric disorder was frequent, with one in three patients suffering from panic attacks and one in eight from depressive illness.
Associated cardiovascular disorders
There was no significant difference between groups in the proportion of patients with associated cardiovascular disorders (Table 1). Hypertension was the most common associated cardiovascular abnormality, present in 21 patients (11%). Probable or definite ischaemic heart disease (as diagnosed by the cardiologist) was present in eight patients (4%). Minor structural cardiac disorders, such as mitral valve prolapse with mild regurgitation, were found in eleven patients (6%). No patient had pre-excitation.
Psychological assessment
Psychiatric disorder using standard DSM-IV criteria was diagnosed in 38 patients (21%) (see Table 3). The most frequent diagnoses were panic disorder and depression. Sixty-two patients (35%) reported panic attacks. Referring letters from General Practitioners mentioned current (n=15) or past (n=8) psychiatric problems in 61% of those identified as having such problems by the research assessment.
Logistic regression
Arrhythmia and awareness of sinus rhythm
Logistic regression analysis was used to test how well the variables included in the study could distinguish patients with arrhythmia from those with awareness of sinus rhythm. The variables making a significant contribution to predicting arrhythmia were: male gender, long history of palpitation, high level of physical activity, presence of associated cardiovascular disorder, and not reporting symptoms during the heart rate perception test (Table 5). Initial 2 was 135.53, and model 2 was 95.40, therefore the change resulting from the model was 40.13, which was significant (df=5, p<0.001). Using these five variables, 78% of patients were classified correctly (80% of arrhythmia, 74% of awareness of sinus rhythm).
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Arrhythmia and benign palpitation
We also examined how well patients with arrhythmias were distinguished from all those with benign palpitation (extrasystole and awareness of sinus rhythm). Two variables made a significant contribution to predicting arrhythmia: long history of palpitation and not reporting symptoms during the heart rate perception test (Table 5). Initial 2 was 210.58, and model 2 was 194.43, therefore the change resulting from the model was 16.15. This small change was significant (df=2, p<0.001), but the model using only these two variables predicted that all patients were in the benign palpitation group.
Three-month outcome
Of 184 patients seen at the clinic and included in the study, 40 patients with benign palpitation received a nurse-delivered psychological intervention in addition to usual care in the RCT described elsewhere.13 Of the remaining 144 patients, 112 (78%) were followed-up at three months. The outcome of these 112 patients is described in Table 6.
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Most patients in each of the three diagnostic groups felt better overall at three months compared to baseline, and about one third of patients were no longer suffering from palpitation. However, a significant minority did not feel better, most continued to suffer from palpitation, and there was considerable remaining disability due to fear of symptoms. The sinus rhythm group had the best outcome at three months, with a significantly greater reduction in disability since baseline than the arrhythmia and extrasystoles groups. However, even in this group, 44% of patients (95%CI 35–76%) were no less disabled than at baseline.
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Discussion |
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Most patients presenting to out-patient secondary care with the presenting complaint of palpitation do not suffer from cardiac arrhythmia, and are suffering from what we term benign palpitation. However, disability and distress attributed to palpitation are considerable, and are as great for those with benign palpitation as for many patients with arrhythmias. Outcome at three months is disappointing, despite usual cardiological care. These findings from a single district clinic, together with those in our companion paper,8 are consistent with, but substantially extend, other published studies of characteristics2,13 and course.5,7
Cardiological diagnosis
The cardiological assessment was in keeping with standard practice.1,14 However, assigning patients to the three diagnostic groups defined by the cardiac rhythm responsible for palpitation has two limitations. The first is that patients with palpitation may be aware of more than one cardiac rhythm. In one study, the cardiac rhythm was different in 7/20 patients (35%) who made two recordings with an event monitor.15 In this study, patients were assigned to the diagnostic category reflecting the dominant, but not necessarily exclusive, cause of their palpitation. The other limitation is that we did not always have ECG confirmation of cardiac rhythm at the time of palpitation. Of course, while ECG confirmation is the gold standard, it is acknowledged that it cannot always be achieved, as symptoms often do not occur during monitoring. In one study, one third of 409 patients who had continuous loop event recorders to investigate palpitation did not report symptoms during a monitoring period of median duration 17 days.16 In clinical practice, ECG monitoring for longer than 24 h is rarely undertaken for palpitation if there is no apparent substrate for arrhythmia. Patients without a definite ECG diagnosis are usually managed according to the most likely diagnosis, based on the available data.
We doubt that these limitations would have systematically misclassified patients. In support of this, patients with probable and definite arrhythmia were not significantly different to each other on a range of measures. Even if misclassification did occur, because diagnosis was made blind to the behavioural and psychological data, this would tend to reduce differences between diagnostic groups, and could not account for the significant group differences.
Within each diagnostic group, there may be substantial diversity in regard to the mechanism of rhythm generation. For example, palpitation due to awareness of sinus tachycardia may reflect panic disorder, thyrotoxicosis or the rare condition of chronic inappropriate sinus tachycardia. Nevertheless, our findings indicate that this potential diversity does not obscure group differences in behavioural and psychological characteristics.
Developing our understanding of aetiology
Previous attempts to classify causes into mutually exclusive cardiac and psychiatric alternatives have been unsatisfactory. This is because some of those with arrhythmias also suffer from psychiatric disorder, and not all patients without cardiac abnormalities report psychological symptoms.2 An alternative approach is to see psychological and behavioural factors affecting the interpretation of perceptions of physiological or pathological processes. These perceptions may be unremarked or accepted as normal by many in the general population. In this study, many patients had a very long history of palpitation prior to consultation. Furthermore, the arrhythmias identified in this group of patients in secondary care are similar to those reported in general population studies.17,18 These findings provide support for psychological rather than cardiological factors driving consultation. Psychological factors may influence the perception of palpitation as unpleasant and abnormal and, thereby, prompt consultation.
Although distress and psychiatric disorder were more common in patients with benign palpitation than in patients with arrhythmia, levels of distress and psychiatric disorder were also high in patients with arrhythmias. Similar processes may therefore be at work. Perhaps reflecting this, few patients with palpitation due to arrhythmia were regarded as having medically serious palpitation, and treatment was largely by reassurance.
Psychological factors should therefore be integrated into the diagnosis of palpitation. The diagnosis of each patient with palpitation may be described on three axes: (i) electrocardiographic findings (arrhythmia, awareness of sinus rhythm, extrasystoles); (ii) associated cardiological disorder; and (iii) psychological status (which only satisfies criteria for psychiatric disorder at its most severe). This approach allows concurrent cardiac and psychological diagnoses, and avoids the problems that have arisen from attempting to distinguish between arrhythmia and panic as alternative categories.19
Clinical implications
Out-patient attenders with palpitation are distressed and disabled, but few require specialist medical treatment.1 For the majority with benign palpitation, specialist cardiological assessment and reassurance is ineffective in alleviating distress and disability. Our findings suggest ways in which the diagnosis and treatment of this challenging patient group could be improved.
Diagnosis could be improved by adding routine assessment of psychological status and disability. Self-report questionnaires such as the Beck Depression Inventory are easily completed by patients and scored and interpreted by staff. The results of a brief heart rate perception test, alongside aspects of history, including length of history of palpitation and level of physical activity, may assist diagnosis. Extending the use of cardiac event recorders may improve cardiological diagnosis,16 and also function by providing reassurance for patients who remain especially worried about the nature of their symptoms. Providing a convincing explanation of the cause of palpitation is the basis of effective treatment.
A minority of patients benefit from pharmacological treatments or from specialist cardiological treatment. Treatment could be improved by additional simple measures designed to provide explanation to the patient and family and to ensure continuity between primary and secondary care. This extra treatment could be provided at three levels or steps:
Step one: Augmenting the usual clinic assessment for all patients
The usual assessment could be bolstered for all patients by providing information to meet patients' individual needs and address their worries, together with advice about coping with symptoms, managing anxiety, and increasing activity. This approach, in which supporting patient self-management is central to treatment, is endorsed by the Department of Health in their Expert Patients Programme.
Step two: Provision of more intensive clinic-based help
Some patients have specific extra needs, such as those with poor heart rate perception or psychiatric disorder. A few patients may benefit from the further information about the nature of palpitation that could be provided by a cardiac event recorder. Patients with poor heart rate perception might benefit from education on the relationship between symptoms and their heart beat. Others might be helped by a brief psychological intervention, similar to that used in treating panic disorder, designed to correct misinterpretation of bodily sensations. We have separately reported the results of an RCT which demonstrate the effectiveness of a brief cardiac nurse-delivered educational and behavioural intervention provided at the hospital approximately one week after attendance at the cardiac clinic.12
Step three: Provision of specialist help
Some patients need specialist psychological care. In addition, a small proportion of patients may need specialist individual care, such as individual cognitive behaviour therapy.
Further research is needed to determine the acceptability, feasibility and clinical and cost effectiveness of this ‘stepped’ approach to the care of patients presenting with palpitation.
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Acknowledgments |
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We are very grateful for help from: Mrs Dorothy Vass and Mrs Elizabeth Tanqueray, who carried out the clinical and research assessments; Professor Anke Ehlers, who collaborated in the psychological assessments; and Mrs Ann Day, for help with the analysis. The study was funded by the British Heart Foundation.
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Address correspondence to Professor R. Mayou, University of Oxford Department of Psychiatry, Warneford Hospital, Oxford OX3 7JX. e-mail: richard.mayou{at}psych.ox.ac.uk
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References |
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