Clinical characteristics of patients with vasovagal reactions presenting as unexplained syncope.

OBJECTIVE

To describe the clinical characteristics of vasovagal syncope (VVS) in patients presenting to a tertiary referral centre with unexplained syncope, in whom the diagnosis of VVS was confirmed by tilt table testing (HUT) and in whom other causes of syncope excluded.

DESIGN

Prospective study of 62 consecutive patients with more than two episodes of syncope in the past year.

SETTING

A regional tertiary referral centre for patients with unexplained syncope.

PATIENTS: Sixty-two patients, mean age 50 +/- 21 years, 39 female, were studied. Mean duration of symptoms was 5 years. Average frequency of attacks was one episode per week.

INTERVENTIONS: Detailed semi-structured questionnaires were completed regarding presenting symptoms.

RESULTS

In over one-third of patients, episodes occurred suddenly, with no prodromal features. In those with prodrome, 71% had autonomic symptoms, but 27% had palpitations or dyspnoea and 21% had chest pain. Eleven percent of patients denied known provocative features. In the remainder, the most common were prolonged standing (37%), hot weather (27%) and lack of food (23%). One-fifth had symptoms sitting and 5% whilst driving. Seventy-five percent of patients suffered after effects, the most common being severe fatigue. Over half sustained an injury during syncope, and 13% sustained a fracture. Unwitnessed episodes occurred in 25%. Pallor was reported in half the cases, sweating in 13% and myoclonus in 5%.

CONCLUSIONS

Atypical presentations of VVS occur in many patients referred to a tertiary referral centre. Knowledge of the clinical characteristics of unexplained syncope for which VVS is the attributable diagnosis should assist in appropriate management of such patients.