Psychological correlates of vasovagal versus medically unexplained syncope

Abstract

Objective

Psychiatric morbidity is quite common in vasovagal syncope (VVS), but findings are sometimes contradictory. Among patients with suspected VVS, up to 40% has a negative response to Head-Up Tilt test (HUT), the cause of syncope remaining unexplained (US). The authors evaluated and compared the psychological and psychosomatic profile in patients with positive (VVS) and negative HUT (US).

Method

A consecutive series of 67 patients with suspected VVS underwent HUT: 45 patients had a positive HUT, 22 negative. They were evaluated by means of observer- and self-rated measures.

Results

Of the total sample, 95.5% had at least one Diagnostic and Statistical Manual of Mental Disorders diagnosis or one psychosomatic syndrome, such as specific and social phobias, illness denial and demoralization. Comparing VVS and US patients, no statistical differences on diagnoses' frequencies were found. However, the US group had significantly poorer health habits, lower levels of well-being and higher psychological distress. They also reported to be more anxious, depressed and hostile. VVS patients were significantly more blood and social phobic than US patients.

Conclusion

Despite similar and remarkable observer-rated psychopathology, US patients reported higher self-perceived psychological distress than VVS patients. Psychological evaluation of patients undergoing HUT should incorporate both clinical and subclinical methods to better address syncope management.

Introduction

Syncope is a sudden transient loss of consciousness associated with a drop in postural tone due to transient global cerebral hypoperfusion and hypoxia. It is characterized by rapid onset, short duration and spontaneous complete recovery [1].

Syncope might have three different kinds of etiology [1]: cardiovascular, orthostatic hypotensive and neurally mediated. Neurally mediated (or reflex) syncope has a prevalence of 21% in the general population [2], with a lifetime cumulative incidence of 35% [3]. It varies from 35% to 48% in patients referred to an emergency department [4], [5], [6] and from 56% to 73% in syncope-dedicated units [5], [7], [8], [9]. Vasovagal syncope (VVS) belongs to this latter group, and it is frequently triggered by emotions or orthostatic stress [1]. Vasovagal etiology is the most frequent cause of syncope in all settings [1]. Among patients with suspected VVS, up to 40% [2], [10] have a negative response to the Head-Up Tilt test (HUT). This medical procedure is specifically designed to diagnose presence of VVS through passive head-up tilting. If vasovagal symptoms are triggered in conjunction with significant decreases in blood pressure, then a diagnosis of VVS is made. HUT-negative patients are mostly identified as having medically unexplained syncope (US) [11].

In the last two decades, the possible association between syncope and psychiatric disorders has been widely explored [12], [13], [14], [15], [16]. Kouakam and colleagues [15] reported a prevalence of psychiatric disorders in 65% of patients referred for HUT, and it was significantly higher than that observed in a control group of arrhythmic patients. While some research highlighted a higher prevalence of psychiatric disorders or psychological distress in US patients compared to the ones with VVS [11], [13], [14], contradictory evidences exist [17], [18], [19]. In addition, studies focusing on the psychological correlates of patients with VVS showed that blood/injury phobia [1], [11], [20], somatization and affective disorders [19] may be common in this population. Leftheriotis and colleagues [21] have also corroborated some earlier evidences in the literature [22] about the high prevalence of minor psychiatric disorders among patients with VVS. The authors show how patients with subclinical depressive symptomatology and anxiety disorders (i.e., panic and generalized anxiety disorder) had an increased rate of positive response to HUT compared to normal controls. On the other hand, studies concerning the psychological correlates of recurrent US suggested that specific psychiatric disorders such as generalized anxiety, panic attacks and major depression can develop in patients with this kind of syncope [12], [23], [24]. Only few studies have investigated psychosomatic complaints of patients with syncope through the use of standard psychiatric nosography. Among these, Ventura et al. [16] evaluated psychosomatic disorders of 26 patients with unexplained syncope by means of self-administered questionnaires and semistructured psychosomatic interview based on criteria from the International Classification of Diseases, 10th Revision. The authors found a prevalence rate of somatization of 12%. In the same vein, Giada et al. [19] found a 10-fold higher prevalence (near 30%) of somatization disorders [according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria] among VVS patients compared to healthy subjects.

However, a wide body of evidence has accumulated in psychosomatic medicine, highlighting both clinical impact and implications of psychosomatic complaints, even in their subclinical presentation, on quality of life and psychological well-being [25], [26], [27]. The Diagnostic Criteria for Psychosomatic Research (DCPR) [25] offer an alternative to the traditional psychiatric nosography and allow the clinician to characterize a patient's mode of perceiving, experiencing, evaluating and responding to his/her health status [28].

Given the paucity of studies comparing VVS and US patients, for what concerns both psychological and psychosomatic profile, the objectives of the present study are (a) to evaluate psychological and psychosomatic distress through the use of reliable observer- and self-rated measures in patients with suspected VVS who underwent tilt testing and (b) to compare it among patients with a positive response to HUT (indicative of VVS) and those with a negative result to tilt testing (indicative of US).