Ambulatory 24 hour ECG in patients with a history of syncope. A retrospective follow-up study over 2 years

174 patients referred to a general hospital for unexplained syncope were examined by ambulatory 24 hour ECG (AECG) and a follow-up by questionnaire after 2 years. The AECG demonstrated sinus rhythm in 113 patients, atrial fibrillation in 15 (in 2 of these there were occasional RR intervals of more than 3 seconds), atrioventricular (AV) block in 10, sinoatrial (SA) block in 14, tachycardia or frequent ventricular extrasystoles (VES) in 21, and no recording (technical failure) in one. Ten patients got a permanent pacemaker due to these findings, and 7 were given antiarrhythmic drug therapy. 121 patients responded to the questionnaire, 37 were dead and 16 lost to follow-up. Of the 121 responders, 36 reported multiple syncopes in the follow-up period, and another 17 one syncope. Eleven patients had received a permanent pacemaker during the follow-up period.