Evaluation of psychopathology in patients with paroxysmal supraventricular tachycardia

Abstract

BACKGROUND

A higher prevalence of anxiety- and depression-related symptoms are expected in patients with at least one somatic disease and who are on medications compared with the general population.

OBJECTIVES

To determine if patients with paroxysmal supraventricular tachycardia (PSVT) show a higher prevalence of anxiety and depressive symptoms compared with a control population. The induction of depressive symptoms by beta-blockers or calcium channel blockers was also evaluated.

METHODS

Twenty-five patients (17 women, eight men) with documented PSVT (atrioventricular re-entrant tachycardia or atrioventricular nodal re-entrant tachycardia) were evaluated by a battery of questionnaires and inventories, which provide information about the presence of symptoms of anxiety and/or depression. All patients were examined by a psychiatrist and completed the following five scales: Symptom Checklist-90, Hamilton Anxiety Scale, Hamilton Depression Rating Scale, Zung’s Self-Rating Depression Scale and Beck Self-Assessment Depression Scale.

RESULTS AND CONCLUSIONS: The majority of the evaluations (Hamilton Anxiety Scale, Beck Self-Assessment Depression Scale, Zung’s Self-Rating Depression Scale), did not show a higher incidence of severe symptoms of depression in the group of patients with PSVT. However, the Hamilton Depression Rating Scale rated the symptoms of depression as significant, but the score was low enough to be considered nonsignificant.

According to the Symptom Checklist-90, men perceived the presence of the cardiological disease more intensively and more negatively than women (P=0.1). Psychiatric history and therapy with psychopharmacological agents were comparable in both groups. It was noted that patients had sporadic contacts with a psychiatrist or a psychologist, but this was not directly associated with PSVT.

Diseases of the cardiovascular system are among the most common diseases of our population and as such represent a significant health and economic problem. The relationship between psychopathology and cardiovascular diseases has been shown to be associated with type of personality and emotional reactivity, but it can result in more severe psychopathological symptoms (1–6). More importantly, it has been shown that comorbid depression increases the risk for mortality in subjects with cardiovascular diseases (ischemic heart disease or chronic heart failure) (7). An increased risk of cardiovascular mortality has been shown in depressive subjects without cardiovascular disease; therefore, it is clear that depression is not the only marker of severity for a cardiovascular disease but it adds to the development thereof (8,9).

The mechanisms explaining the relationship between depression and the cardiovascular system can be understood at the pathophysiological and behavioural levels (9,10). Specific pathophysiological changes in the cardiovascular system are caused by depression. In particular, these include an increase in platelet aggregation and heart rate, and a decrease in the variability of heart rhythm mediated by the imbalance of the autonomous nervous system (decrease in parasympathetic nervous system tone). During depression, a deficient immune system along with hypercortisolemia, which can cause the increase of insulin resistance, increase the production of steroids thereby increasing blood pressure. These factors significantly contribute to the increased risk of the development of cardiovascular diseases. Patients with depression also tend to lead unhealthy lifestyles.

In the present study, the incidence of psychopathological symptoms in patients with paroxysmal supraventricular tachycardia (PSVT) was assessed.

The PSVTs include several types of arrhythmias with various causal mechanisms. One of the most common PSVTs is atrioventricular nodal re-entrant tachycardia (AVNRT). Another very common PSVT is atrioventricular re-entrant tachycardia (AVRT), which arises due to the presence of an accessory pathway.

The hemodynamic consequences are similar in both of these PSVTs, which include the shortening of the diastolic filling time of the ventricles, and varying degrees of impairment of synchronization of diastolic filling times of the ventricles and ventricular contraction. This may result in palpitations, dyspnea, hyperventilation, dizziness, sweating, chest pain and anxiety.

From a clinical point of view it is important to note that both of the above-mentioned forms of PSVT are cured in almost 100% of cases using radiofrequency ablation (RFA).

The current literature reviews provide insufficient information concerning the psychopathology of patients with PSVT. In general, the psychopathological aspects should include common prevalence of 12-month diagnosis of depressive disorder in the adult European population (7%) (11), the somatic symptoms accompanying arrhythmias and individual sensibility of each patient. In addition, the intensity of symptoms such as the frequency, timing and suddenness of episodes, which often force patients to seek emergency medical help and may resemble panic disorder (or be its trigger) (1,12–15), have to be considered. The coincidence of panic and depressive disorders is very frequent but the diagnosis of ‘pure’ depressive or panic disorder is very rare; the comorbidity among mentally ill patients is estimated to be approximately 50% (11). The facts mentioned above may play a role in the pathogenesis of psychic disorders, especially by means of activation of the vegetative nervous system (9).

Currently, the role of severe somatic diseases as chronic stressors in the pathogenesis of depressive disorders is often discussed. The functional length polymorphism in the promoter of the serotonin transporter (5-HTT) gene moderates the influence of stressful life events on symptoms of depression. It was found that individuals with one or two ‘short’ alleles at this polymorphism were more stress-sensitive than those with two ‘long’ alleles (16–18). This finding may support our hypothesis that a higher incidence of depressive disorder is expected in patients with PSVT.

At the same time, identification of a hypothetically presumed anxiety-depression symptomatology would provide adequate indication for psychopharmacological intervention, which may, similar to patients after acute myocardial infarction, decrease the late morbidity (19).

HYPOTHESIS

Patients with PSVT have a higher prevalence of anxiety-depressive symptoms that is associated with the presence of at least one somatic disease and the side effects of medication used to treat the somatic diseases (eg, the induction of depressive symptoms by beta-blockers or calcium channel blockers) (16–18).

METHODS

A battery of five psychiatric scales were used to evaluate 25 patients who came consecutively for an elective RFA at the Department of Cardiology, Institute for Clinical and Experimental Medicine in Prague (Czech Republic), between June 2000 and January 2001. It is important to note that for the indication of the RFA, in some cases the arrhythmia was not proven by electrocardiogram, but a clearly positive history of paroxysmal palpitations, or signs of preexcitation on the electrocardiogram during the sinus rhythm and the history of palpitations, were required.

After signing the informed consent, all patients underwent a physical examination, electrocardiography, echocardiography and standard preoperative laboratory tests, which included a basic biochemical analysis of blood serum and coagulation parameters. The psychiatric examination was performed by a clinical interview (to get psychiatric personal and family history) and by the use of psychiatric scales as a part of the preablation test protocol. The psychiatric examination was performed by a single psychiatrist who was specially trained in the administration of the psychiatric assessment scales used in the present study.

Informed consent and instructions for patients were approved by the local ethics committee at General Teaching Hospital in Prague (Czech Republic) in August 2000.

Testing methods

The following battery of tests were given before the RFA: Hamilton Depression Rating Scale (HAMD) (20), Hamilton Anxiety Scale (HAMA) (21–23), Beck Self-Assessment Depression Scale (BECK) (24,25), Symptom Checklist-90 (SCL-90) (26) and Zung’s Self-Rating Depression Scale (SDS) (27,28). The battery of tests were completed individually in the presence of the administrator for a minimum of 6 h before the procedure, and there was no time limit.

Statistical analysis

The basic statistical parameters (mean, SD, standard error of the mean, minimum and maximum values) were calculated for the whole sample of patients (Table 1).

TABLE 1.

Basic characteristics for the whole sample (n=25), women (n=17) and men (n=8)

Parameter	Sex	Mean ± SD	Standard error	Range
Age, years	Male	33.5±11.9	4.2	18 to 50
	Female	41.6±13.9	3.4	22 to 72
	Total	39.0±13.6	2.7	18 to 72
Duration of symptoms, years	Male	9.8±8.7	3.1	0.5 to 19
	Female	13.9±14.5	3.5	1.0 to 50
	Total	12.6±12.8	2.6	0.5 to 50
SCL-90 total score	Male	90.7±29.6	10.5	45 to 134
	Female	60.9±35.8	8.7	17 to 152
	Total	70.5±36.2	7.2	17 to 152
GSI	Male	1.01±0.33	0.12	0.50 to 1.49
	Female	0.68±0.40	0.10	0.19 to 1.69
	Total	0.78±0.40	0.08	0.19 to 1.69
PST	Male	54.4±16.4	5.8	34 to 82
	Female	38.6±19.1	4.6	12 to 90
	Total	43.7±19.4	3.9	12 to 90
PSDI	Male	1.66±0.23	0.08	1.32 to 1.98
	Female	1.51±0.25	0.06	1.08 to 1.89
	Total	1.56±0.25	0.05	1.08 to 1.98
HAMA	Male	18.1±6.2	2.2	10 to 26
	Female	17.9±9.2	2.2	4 to 38
	Total	18.0±8.2	1.6	4 to 38
HAMD	Male	8.5±4.5	1.6	2 to 17
	Female	8.1±3.8	0.9	0 to 16
	Total	8.2±3.9	0.8	0 to 17
BECK	Male	4.6±3.5	1.2	0 to 9
	Female	4.1±2.7	0.7	0 to 9
	Total	4.3±2.9	0.6	0 to 9
SDS index	Male	49.9±8.3	2.9	36 to 65
	Female	47.8±9.6	2.3	30 to 69
	Total	48.5±9.1	1.8	30 to 69

BECK Beck Self-Assessment Depression Scale; GSI Global symptom index (transformed score of the Symptom Checklist-90 [SCL-90]); HAMA Hamilton Anxiety Scale; HAMD Hamilton Depression Rating Scale; PST Positive symptom total (the number of positive symptoms in the SCL-90); PSDI Positive symptom distress index (the ratio between the total score reached in a scale and the number of positive symptoms); SDS Zung’s self-rating depression scale

The transformed scores of the SCL-90 were used for statistical analysis. The global symptom index is the ratio of the total score and the total number of questions (90 questions). The positive symptom total is the number of nonzero answers to the scale questions. Average severity of a symptom is the ratio of the total score reached in a scale and the number of positive symptoms.

For the statistical analysis of the SDS, the value of the SDS index was used, which is considered to be the final result representing the level of depression within the maximum score of the scale.

RESULTS

The group of 25 patients (17 women and eight men) were evaluated (mean age 39.0±13.6 years, mean disease duration 12.6±12.8 years). Based on the electrophysiological findings, 14 patients were assigned to the AVNRT group (mean age 41.5±14.0 years, mean disease duration 12.6±11.9 years) and 11 patients were assigned to the AVRT group (mean age 35.8±13.1 years, mean disease duration 12.6±14.5 years) (Table 1).

The mean values of the total scores in the administered anxiety and depression psychiatric scales were HAMA 18.0±8.2, BECK 4.3±2.9 and SDS index 48.5±9.1. The mean score in HAMD was 8.2±3.9, which although technically significant was low enough to be considered insignificant.

The self-administered SCL-90 serves as an inventory of symptoms across all spectrum of psychiatric diagnosis.

The number of positive answers indicates the subjective information about patients’ specific problems. The total score of SCL-90, total transformed scores of global symptom index and positive symptom total were statisticaly higher in men (P=0.1) than in women.

Psychiatric history

These data were obtained from the clinical interview with the patient before the scales were administered.

At the time of examination, none of the patients were seeing a psychiatrist or a psychologist. However, in the AVRT group, there were two patients who had previous contacts with a psychiatrist. One patient saw a psychiatrist for short-term problems associated with a matrimonial crisis (1996). After this, she did not seek any psychiatric care. The other patient was receiving diazepam for transient problems in the past (minor mood disorder, anxiety and insomnia).

In the AVNRT group, there were also two patients who had previous contacts with a psychiatrist. One of them was a young patient who had been examined upon the request of the school for suspicion of alcohol abuse and school problems. Another patient had sought help for symptoms of depression associated with a matrimonial crisis. Therefore, only a small number of patients received specialized psychiatric or psychological care together with the cardiological care. None of the patients had sought the help of a psychiatrist or a psychologist for symptoms directly connected to PSVT.

Conclusions

The present study did not show that the psychiatric scales focusing on the presence of anxiety-depressive symptoms (HAMA, BECK and SDS) had a higher incidence of severe symptoms of depression in the group of patients with PSVT. The HAMD reached statistical significance, but the scores were low enough that they could be considered insignificant.

According to the SCL-90 total score, men perceived the presence of the cardiological disease more intensively and more negatively than women.

In both groups (AVRT and AVNRT), psychiatric history and therapy with psychopharmacological agents were comparable. Generally, only sporadic contacts with psychiatrists or psychologists that had no direct connections to PSVT were noted.

DISCUSSION

In the present study, we gathered data concerning the occurrence of psychopathological symptoms in patients with PSVT. According to current literature, with the exception of sporadic case reports (29), similar studies have not yet been published.

Standardized psychiatric scales focusing on depression and anxiety were used. These scales are neither time-consuming nor demanding for patients. We preferred clinical examinations performed by a psychiatrist to more time-consuming structured interviews (eg, Mini International Neuropsychiatric Interview).

Despite approximately 7% prevalence of depressive disorder in the adult European population (11), our results from the administered scales showed an absence of depression and anxiety. These results may relate to the small sample of subjects. Anxiety, which was expected as a natural feature, was surprisingly low. However, psychiatric scales represent only secondary diagnostic devices and do not cover all the symptoms; therefore, all symptoms may not have been recorded. Another reason for the low level of anxiety may be that patients regard some problems as an integral part of the chronic somatic disease, and are not able to differentiate such symptoms on targeted questions.

The large variation of scores obtained in the psychiatric scales may have been caused by ‘roughness’ of used diagnostic devices (scales contain only clearly differentiated symptoms, subliminal forms are not included). It may be useful to choose another standardized form of administration of the scales –cards or computer administration instead of questionnaires.

A major limitation of the present study is that the results of our observations were likely biased because of the small patient sample. Uneven male to female ratio resulting from the way patients were recruited may also be limiting. Our group consisted of subjects consecutively admitted to the inpatient arrhythmia unit of Institute for Clinical and Experimental Medicine in Prague (Czech Republic) in predefined time intervals (June 2000 to January 2001). However, with regard to the prevalence of psychopathology in male and female patients and our negative findings, we considered the uneven male to female ratio in our study to be nonessential.

Our original plan to assess psychopathological features separately in subgroups of patients with AVRT and AVNRT was abandoned because of the low number of subjects in both groups and the lack of evidence-based data for diversity in psychopathology.

The aim of the present study was to characterize psychopathological features in a defined group of patients with cardiac diseases using selected standardized scales. These scales fulfil set criteria such as a sufficient number of control subjects (adults, elderly), sufficient validity and reliability (20–22,25–28). The scales have already been validated for healthy controls and therefore we did not include the control group in our trial. In light of negative psychopathology results, we hypothesize that the eventual assessment of the control group with another cardiac problem and psychiatric comorbidity would not yield any other profit. If positive results of psychopathology were found, the control group would be necessary to confirm or refute specificity of symptoms in specific cardiological diseases.

In conclusion, there is little known about the mutual relationships between arrhythmias and anxiety-depressive disorders in subjects without a structural impairment of the heart. The first study focusing on this type of cardiovascular disorder was published in 1999 (30). The observations in this study were made by cardiologists and were focused predominantly on the quality of life of patients after the RFA. The psychopathological profile of the studied sample of patients was touched only marginally. Consistent data pertinent to the presented topic are therefore missing. The presented observations of patients with PSVT are unique, not only in Czech Republic but, also according to available literature, abroad.