부산대학교 도서관

Rationale: Infrequent arrhythmic events are rarely recorded by 24-hour Holter, while insertable event record (ILR) are expensive and involve minor surgical procedure. New generations of external loop recorders (ELR) with high memory capacity and auto-trigger functions could be a valid alternative for the diagnosis of infrequent arrhythmic events.Methods: We utilized new extended-memory ELRs (SpiderFlash-T®, Sorin Group Inc) that record up to 30 days with backward-forward memory (max 900 sec) by 3 modes of activations: a) Autotrigger functions activated by pauses (RR>2.5 sec), bradycardia (HR<40 bpm), supraventricular tachycardia (SVT, HR>150 bpm), ventricular tachycardia (VT), paroxysmal atrial fibrillation (PAF); b) Automatic recordings at preselected daily intervals; c) By patient activation during symptoms. The study group included 196 patients (pts, 57% females, mean age 35±18 yrs, range 7-85 yrs) with history of unexplained palpitations (125 pts, 64%) or syncope (71 pts, 36%). All pts had standard 24-hour HM prior to ER monitoring, without documented significant arrhythmias.Results: During ELR monitoring, lasting 25±3 days (range 6-31 days), 122/196 pts (62%) had reoccurrence of events (palpitations or syncope). Among pts with history of palpitations, events occurred in 103/125 pts (82%). During palpitations, ELR recorded paroxysmal supraventricular tachycardia (11% of cases), paroxysmal atrial fibrillation (13%), non-sustained ventricular tachicardia (2%), supraventricular or ventricular beats (41%), and sinus tachycardia (HR>100 bpm) (34%). Among pts with history of syncope, 19/71 pts (27%) had recurrence of syncope during monitoring. During syncope, ELR recorded critical pauses (RR 3-18 sec) during SR or during PAF i (32% of cases), sinus bradycardia (HR<40 bpm) and non critical pauses (RR 2-3 sec) during PAF or due to 2nd degree AVB Mobitz (21%), sinus tachicardia (HR>100 bpm) (26%) or regular sinus rhythm (HR 60-90 bpm) with isolated SVEB or VEB (21%).Conclusions: New ELRs with autotrigger functions and high-memory capabilities represent a valid first-line procedure for the diagnosis of infrequent arrhythmic events. ELRs were more effective for diagnosis of palpitations and less effective for syncope, due to lower recurrence rate. New ELRs similar to Holter monitoring are noninvasive, inexpensive and easy to use and can be used without unnecessary cost, risk and discomfort for the patient. More expensive and minimally invasive techniques, such as ILR, should be utilized in a step-wise approach in those patients where a diagnosis could not be obtained after one-month noninvasive monitoring.