P413Aetiology of syncope and orthostatic intolerance in older patients with pacemakers: SYSTEMA cohort

Abstract

Background: Pacemaker (PM) therapy is usually successful in bradyarrhythmia. However, recurrent syncope and orthostatic intolerance in patients treated with PM is a common dilemma, especially in the elderly. Purpose: We aimed to determine the aetiology of recurrent and unexplained syncope and/or symptoms of orthostatic intolerance in patients with implanted PM aged 65 years or more. Methods: Among 616 patients > 65 years that were investigated by head-up-tilt-test (HUT) in a tertiary syncope unit, 26 patients (4.2 %) had a pacemaker at referral. In these patients, we explored symptoms, final HUT diagnoses, and further clinical workup, if the diagnosis was not obtained during the initial assessment, including HUT. Results: The indication PM therapy in the 26 patients at the time of referral was sick sinus in 10, AV-block in 10, atrial fibrilation (AF) with bradycardia in 5 and ventricular tachycardia in 1 (PM + cardioverter defibrillator). Patients' characteristics, their medical history and the final HUT-derived diagnoses are displayed in Table 1. During further workup in the five patients without diagnosis after HUT, one was found to have ventricular tachycardia and a cardioverter-defibrillator was implanted. In four patients (3 with syncope and 1 with orthostatic intolerance), no clear aetiology was established. The PM-indications in these patients followed guidelines (1 sick-sinus, 2 AVblock, 1 AF with bradycardia). During follow-up one of these patients died due to complications of diabetes, another had a stroke and a third had percutaneous coronary intervention. Conclusions: In older patients with syncope and/or orthostatic intolerance despite pacing therapy, tilt testing and carotid sinus massage may provide the aetiology in 8/10 patients. The most common diagnosis is orthostatic hypotension, which was found in 50 %. Patients in whom no aetiology can be determined after the intitial evaluation, including tilt, seem to carry a poor prognosis and additional investigations into cardiovascular disease may be warranted.