BACKGROUND: Defibrillation therapy for atrial fibrillation (AF) and flutter (AFl) is limited by pain induced by high-energy shocks. Thus, lowering the defibrillation energy for AFl/AF is desirable. OBJECTIVE: In this study we applied low-voltage multiple-shock defibrillation therapy in a rabbit model of atrial tachyarrhythmias comparing its efficacy to single shocks and antitachycardia pacing (ATP). METHODS: Optical mapping was performed in Langendorff-perfused rabbit hearts (n = 18). Acetylcholine (7 ± 5 to 17 ± 16 μM) was administered to promote sustained AFl and AF, respectively. Single and multiple monophasic shocks were applied within 1 or 2 cycle lengths (CLs) of the arrhythmia. RESULTS: We observed AFl (CL = 83 ± 15 ms, n = 17) and AF (CL = 50 ± 8 ms, n = 11). ATP had a success rate of 66.7% in the case of AFl, but no success with AF (n = 9). Low-voltage multiple shocks had 100% success for both arrhythmias. Multiple low-voltage shocks terminated AFl at 0.86 ± 0.73 V/cm (within 1 CL) and 0.28 ± 0.13 V/cm (within 2 CLs), as compared with single shocks at 2.12 ± 1.31 V/cm (P < .001) and AF at 3.46 ± 3 V/cm (within 1 CL), as compared with single shocks at 6.83 ± 3.12 V/cm (P =.06). No ventricular arrhythmias were induced. Optical mapping revealed that termination of AFl was achieved by a properly timed, local shock-induced wave that collides with the arrhythmia wavefront, whereas AF required the majority of atrial tissue to be excited and reset for termination. CONCLUSION: Low-voltage multiple-shock therapy terminates AFl and AF with different mechanisms and thresholds based on spatiotemporal characteristics of the arrhythmias.
BACKGROUND: Defibrillation therapy for atrial fibrillation (AF) and flutter (AFl) is limited by pain induced by high-energy shocks. Thus, lowering the defibrillation energy for AFl/AF is desirable. OBJECTIVE: In this study we applied low-voltage multiple-shock defibrillation therapy in a rabbit model of atrial tachyarrhythmias comparing its efficacy to single shocks and antitachycardia pacing (ATP). METHODS: Optical mapping was performed in Langendorff-perfused rabbit hearts (n = 18). Acetylcholine (7 ± 5 to 17 ± 16 μM) was administered to promote sustained AFl and AF, respectively. Single and multiple monophasic shocks were applied within 1 or 2 cycle lengths (CLs) of the arrhythmia. RESULTS: We observed AFl (CL = 83 ± 15 ms, n = 17) and AF (CL = 50 ± 8 ms, n = 11). ATP had a success rate of 66.7% in the case of AFl, but no success with AF (n = 9). Low-voltage multiple shocks had 100% success for both arrhythmias. Multiple low-voltage shocks terminated AFl at 0.86 ± 0.73 V/cm (within 1 CL) and 0.28 ± 0.13 V/cm (within 2 CLs), as compared with single shocks at 2.12 ± 1.31 V/cm (P < .001) and AF at 3.46 ± 3 V/cm (within 1 CL), as compared with single shocks at 6.83 ± 3.12 V/cm (P =.06). No ventricular arrhythmias were induced. Optical mapping revealed that termination of AFl was achieved by a properly timed, local shock-induced wave that collides with the arrhythmia wavefront, whereas AF required the majority of atrial tissue to be excited and reset for termination. CONCLUSION: Low-voltage multiple-shock therapy terminates AFl and AF with different mechanisms and thresholds based on spatiotemporal characteristics of the arrhythmias.
Authors: Crystal M Ripplinger; Valentin I Krinsky; Vladimir P Nikolski; Igor R Efimov Journal: Am J Physiol Heart Circ Physiol Date: 2006-02-24 Impact factor: 4.733
Authors: Rudolph W Koster; Paul Dorian; Fred W Chapman; Paul W Schmitt; Sharon G O'Grady; Robert G Walker Journal: Am Heart J Date: 2004-05 Impact factor: 4.749
Authors: Flavio H Fenton; Stefan Luther; Elizabeth M Cherry; Niels F Otani; Valentin Krinsky; Alain Pumir; Eberhard Bodenschatz; Robert F Gilmour Journal: Circulation Date: 2009-07-27 Impact factor: 29.690
Authors: Yuanna Cheng; Li Li; Vladimir Nikolski; Don W Wallick; Igor R Efimov Journal: Am J Physiol Heart Circ Physiol Date: 2003-09-04 Impact factor: 4.733
Authors: Harikrishna Tandri; Seth H Weinberg; Kelly C Chang; Renjun Zhu; Natalia A Trayanova; Leslie Tung; Ronald D Berger Journal: Sci Transl Med Date: 2011-09-28 Impact factor: 17.956
Authors: Jacob I Laughner; Fu Siong Ng; Matthew S Sulkin; R Martin Arthur; Igor R Efimov Journal: Am J Physiol Heart Circ Physiol Date: 2012-07-20 Impact factor: 4.733
Authors: Wenwen Li; Ajit H Janardhan; Vadim V Fedorov; Qun Sha; Richard B Schuessler; Igor R Efimov Journal: Circ Arrhythm Electrophysiol Date: 2011-10-06
Authors: Ajit H Janardhan; Sarah R Gutbrod; Wenwen Li; Di Lang; Richard B Schuessler; Igor R Efimov Journal: J Am Coll Cardiol Date: 2013-09-26 Impact factor: 24.094