284 - ORIGINS OF HEART RATE VARIABILITY. HEART RATE BURST RECOVERY PROVIDES A SIMPLE, INDUCIBLE ESTIMATE OF BARORECEPTOR SENSITIVITY
D Roach, ML Koshman, RS Sheldon
Calgary, Alberta

285 - SIMULATED MICROGRAVITY INDUCES MICROVOLT T-WAVE ALTERNANS
SM Grenon, X Xiao, S Hurwitz, CD Ramsdell, N Sheynberg, C Kim, GH Williams, RJ Cohen
Montreal, Quebec; Boston, Massachusetts; Cambridge, Massachusetts, USA

286 - THE PREVENTION OF SYNCOPE TRIAL (POST): A RANDOMIZED, PLACEBO-CONTROLLED STUDY OF METOPROLOL IN THE PREVENTION OF VASOVAGAL SYNCOPE
RS Sheldon, S Connelly, S Rose, T Klingenheben, A Krahn, C Morillo, M Talijic, T Kus, F Fouad-Terazi, D Ritchie, ML Koshman
Calgary, Alberta

287 - CHARACTERIZATION OF BEAT-TO-BEAT CARDIAC-HEMODYNAMIC VARIABLES PRIOR TO NEURALLY MEDIATED SYNCOPE (NMS) INDUCED BY ORTHOSTATIC STRESS: NEW INSIGHTS INTO THE MECHANISMS OF NMS
JC Guzman, MV Kamath, R Dillenburg, SJ Connolly, CA Morillo
Hamilton, Ontario

288 - SYMPTOMS ASSOCIATED WITH VASOVAGAL SYNCOPE PREDICT IMPROVEMENT IN PATIENTS WITH PACEMAKERS
RS Sheldon, AS Sheldon, ML Koshman, D Ritchie, M Fisher
Calgary, Alberta

289 - CAN WE SUSTAIN THE HIGH COST OF AMBULATORY MONITORING FOR "COMMUNITY-ACQUIRED" SYNCOPE? COST ANALYSIS OF A RANDOMIZED TRIAL OF EXTERNAL LOOP VERSUS HOLTER MONITORING
MA Rockx, AD Krahn, JS Hoch, GJ Klein, AC Skanes, R Yee
London, Ontario