OBJECTIVES: The purpose of this study was to characterize interactions between normal pacing system operation and the initiating sequence of ventricular tachycardia (VT)/ventricular fibrillation (VF). BACKGROUND: Abrupt changes in ventricular cycle lengths (short-long-short, S-L-S) might initiate VT/VF. The S-L-S sequences might be passively permitted or actively facilitated by bradycardia pacing. METHODS: Initiating sequences of 1,356 VT/VF episodes in the PainFree Rx II (n = 634) and EnTrust Trial (n = 421) were analyzed with stored electrograms and by pacing mode (DDD/R, VVI/R, and Managed Ventricular Pacing [MVP]). Interactions between pacing and VT/VF initiation were classified as: non-pacing associated, pacing associated, pacing permitted, and pacing facilitated. RESULTS: Non-pacing associated (no pacing, no S-L-S) and pacing associated (ventricular pacing without S-L-S) onset accounted for 44.0% and 29.8% of all VT/VF, respectively. Pacing permitted (S-L-S sequences without ventricular pacing) episodes accounted for 6.4% (DDD/R), 20.0% (MVP), and 25.6% (VVI/R) of 1,356 VT/VF episodes. Pacing facilitated onset (S-L-S sequences actively facilitated by ventricular pacing including the terminal beat after a pause) accounted for 8.2% (MVP), 9.4% (VVI/R), and 14.8% (DDD/R) of 1,356 VT/VF episodes. Pacing facilitated S-L-S VT/VF occurred in 2.6% (MVP), 3.3% (VVI/R), and 5.2% (DDD/R) of patients with episodes and was the sole initiating sequence in approximately 1% of patients. Pause durations during pacing facilitated S-L-S differed between modes (DDD/R 793 +/- 172 ms vs. MVP 865 +/- 278 ms vs. VVI/R 1180 +/- 414 ms, p = 0.002). The majority of these episodes were monomorphic VT. CONCLUSIONS: Ventricular tachycardia/VF in some implantable cardioverter-defibrillator patients might be initiated by S-L-S sequences that are actively facilitated by bradycardia pacing operation and might constitute an important mechanism of ventricular proarrhythmia.
OBJECTIVES: The purpose of this study was to characterize interactions between normal pacing system operation and the initiating sequence of ventricular tachycardia (VT)/ventricular fibrillation (VF). BACKGROUND: Abrupt changes in ventricular cycle lengths (short-long-short, S-L-S) might initiate VT/VF. The S-L-S sequences might be passively permitted or actively facilitated by bradycardia pacing. METHODS: Initiating sequences of 1,356 VT/VF episodes in the PainFree Rx II (n = 634) and EnTrust Trial (n = 421) were analyzed with stored electrograms and by pacing mode (DDD/R, VVI/R, and Managed Ventricular Pacing [MVP]). Interactions between pacing and VT/VF initiation were classified as: non-pacing associated, pacing associated, pacing permitted, and pacing facilitated. RESULTS: Non-pacing associated (no pacing, no S-L-S) and pacing associated (ventricular pacing without S-L-S) onset accounted for 44.0% and 29.8% of allVT/VF, respectively. Pacing permitted (S-L-S sequences without ventricular pacing) episodes accounted for 6.4% (DDD/R), 20.0% (MVP), and 25.6% (VVI/R) of 1,356 VT/VF episodes. Pacing facilitated onset (S-L-S sequences actively facilitated by ventricular pacing including the terminal beat after a pause) accounted for 8.2% (MVP), 9.4% (VVI/R), and 14.8% (DDD/R) of 1,356 VT/VF episodes. Pacing facilitated S-L-SVT/VF occurred in 2.6% (MVP), 3.3% (VVI/R), and 5.2% (DDD/R) of patients with episodes and was the sole initiating sequence in approximately 1% of patients. Pause durations during pacing facilitated S-L-S differed between modes (DDD/R 793 +/- 172 ms vs. MVP 865 +/- 278 ms vs. VVI/R 1180 +/- 414 ms, p = 0.002). The majority of these episodes were monomorphic VT. CONCLUSIONS:Ventricular tachycardia/VF in some implantable cardioverter-defibrillator patients might be initiated by S-L-S sequences that are actively facilitated by bradycardia pacing operation and might constitute an important mechanism of ventricular proarrhythmia.
Authors: Leonardo Calò; Tiziana De Santo; Francesca Nuccio; Luigi Sciarra; Lucia De Luca; Lorenza Mangoni di S Stefano; Enrico Piroli; Lorenzo Zuccaro; Marco Rebecchi; Ermenegildo de Ruvo; Ernesto Lioy Journal: Ann Noninvasive Electrocardiol Date: 2011-10 Impact factor: 1.468
Authors: Martin K Stiles; Arthur A M Wilde; Dominic J Abrams; Michael J Ackerman; Christine M Albert; Elijah R Behr; Sumeet S Chugh; Martina C Cornel; Karen Gardner; Jodie Ingles; Cynthia A James; Jyh-Ming Jimmy Juang; Stefan Kääb; Elizabeth S Kaufman; Andrew D Krahn; Steven A Lubitz; Heather MacLeod; Carlos A Morillo; Koonlawee Nademanee; Vincent Probst; Elizabeth V Saarel; Luciana Sacilotto; Christopher Semsarian; Mary N Sheppard; Wataru Shimizu; Jonathan R Skinner; Jacob Tfelt-Hansen; Dao Wu Wang Journal: Heart Rhythm Date: 2020-10-19 Impact factor: 6.343
Authors: Douglas L Packer; Jordan M Prutkin; Anne S Hellkamp; L Brent Mitchell; Robert C Bernstein; Freda Wood; John P Boehmer; Mark D Carlson; Robert P Frantz; Steve E McNulty; Joseph G Rogers; Jill Anderson; George W Johnson; Mary Norine Walsh; Jeanne E Poole; Daniel B Mark; Kerry L Lee; Gust H Bardy Journal: Circulation Date: 2009-11-16 Impact factor: 29.690