1087 Implantable Cardioverter Defibrillator Utilization Among Device Recipients Presenting Exclusively witb Syncope or Near-Syncope ARIE MILITIANU, M.D.J ABRAHAM SALACATA, M.D..^ KAREN SEIBBRT. R.N.,' RICHARD KEHOE. M.D..' JOHN J. BAGA. MD..' MARC D. MEISSNER. M.D..^ LUIS A. PIRES, M.D.J CLAUDIO D. SCHUGER, M.D.J RUSSELL T. STEINMAN. M.D.J ROBERT D. MOSTELLER, M.D./ AMOS J. PALTI. M.D.,6 JOSEPH BEN DAVID. M.D.,^ TIMOTHY J. LESSMEIER, M.D.,'^ and MICHAEL H. LEHMANN, M.D.' From 'The Arrhythniia Ccnter/Sinai Hospital and Si. John Huspiial. Delroiu Michigan; -Harper HospiialAVayne State University. Detroit. Michigan; 'Illinois Masonic Medical Center. Chicago. Illinois; •'Akron City Hospital, Akron. Ohio; *Heart Clinics Northv^'est. Spokane. Washington; and "Departmenl ot Cardiology. The Lady Davis C:irmcl Medical Center. Haila, Israel ICD Use in Syncope. Introduction: Implantabic cardioverter deflbritlators (ICI)s> are occa- sionullv used in presumed hi}>h-risk patients with electrocurdioj»rapliitiilly undocumented syn- cope. :ilth(iu;<h the incidence of ventricular tachyarrhythmias in this population is not well delined. Methods and Kesttlts: We studied 33 consecutive patients receiving; an I("l) (67% nonthoraco- toniy and 70% tiered therapy) after electrophysiologic testing lor unmonitored "syncope" (n = 29) or "near-syncope" (n = 4). Atherosclerotic heart disease was present in 24 (73%); mean left ventricular ejection fraction (LVEF) was 0.3M ± 0.15; and sustained monomorphic ventricular tacli}cardia (SM\"r) was inducible in 18 (55%). Over a median follow-up of 17 months (rau}>e 4 to 61), 12 patients (36%) received > 1 appropriate ICD discharge trijijiered by SMVT (cycle length 230 lo 375 msec) hi 10 and ventricular Mutter or fibrillation in 2—without couconiitaiit antiarrhytliniic medication in 8 of 12 cases, inducihlc SMVT and lAKK < 0.35 were statisti- cally significant, independent predictors of an appropriate ICD discharge- (P < 0.02 and P < 0.03, respectively). Kstimated I -year cumulative survival free of appropriate discharge was 34% versus S7%, respectively, in patients with versus without inducible SMV T (P - 0.02). and 18% versus 56%, respeetively, in patients with LVEF < 0.35 versus LVKF > 0.35 (P < 0.03). Conclusion: In this highly select, multicenter population of ICD recipients with electrocar- diographically undocumented syncope, a substantial incidence of appropriate device dis- charges was observed, particularly in patients with inducible SMVT and LVEF < 0.35. These findings support the notion that, in patients with LV dysfunction and iuducible SMVT, ventric- ular tachyarrh} thmias are likely to account for episodes of syncope or near-syncope, f./ Cardio- vasc Electrophysiol, Vol. 8, pp. 1087-1097, October 1997) itnptantahlc cardioverter defibrillator. syncope, ventricular tachyarrhythmias, electrophysiologic testing PresenlotI in parl al Iho I7lh Annual Scientific Sessions of the Introduction Nonh AnuTiean Sociciy ol' Piicing and Electrophysiology, Seattle. Wiisliingion. May \fi-h, 19%. A large b(idy of clinical data tiow exists attest- 77; ~ ~ >..•,.,,,. u w r, -ru * i"S to the ability of implantable cardioveiier de- Address lor Lorrcspondenee; Michael H. Lehmann. M.D., The Ar- "^ -^ ' rhythinia Cenier/.Sijiai Hospital. I48(K) West McNichols. Ste. 410. ttbrtilators (ICDs) to abort sudden cardiac deatb.' t)etrni(. M! A^2?'^. Fax: .M.i-4W-73«6. However, ptiblisbetl series tienionslratin^ this cliii- p 1.1 September IW6: Accepted for piiblicatioti •^•*i' hcucVw. generally bave involved heterogeneous tW7 bigb-Hsk populations with various presenting ar-