Premium
Do the Effects of Antiarrhythmic Drugs on Defibrillation Efficacy Vary among Different Shock Waveforms?
Author(s) -
MURAKAWA YUJI,
YAMASHITA TAKESHI,
KANESE YUKIHIRO,
OMATA MASAO
Publication year - 1998
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/j.1540-8159.1998.tb00009.x
Subject(s) - medicine , defibrillation , shock (circulatory) , defibrillation threshold , cardiology , electric shock , physics , quantum mechanics
This study was designed to extend our knowledge on how pharmacological modification of defibrillation efficacy is associated with shock waveform. In 35 anesthetized dogs, the baseline transcardiac DFT was determined using 12‐ms monophasic and three biphasic waveforms(10 ms‐2 ms, 8 ms‐4 ms, and 6 ms‐6 ms). Twenty‐eight dogs were then treated with either lidocaine (n= 7). mexiletine (n = 7), dofetilide (n = 7), or MS‐551 (n = 7), while 7 dogs were left untreated to confirm the reproducibility of DFT data. Subsequently, DFT measurements were repeated in all dogs. Waveform related differences of the baseline DFT were significant, and the monophasic DFT was higher than any of the biphasic DFTs. Lidocaine increased DFT by 11%± 12% (12‐ms monophasic), 20%± 20% (10 ms‐2 ms, P < 0.05), 13%± 20% (8 ms‐4 ms), and 12%± 10% (6 ms‐6 ms, P < 0.05). With infusion of mexiletine. the DFT increased by 17%± 16% (P < 0.05), 9% i 12%, 10%± 10% (P < 0.05), and 4%± 15%, respectively. Both dofetiiide and MS‐551 significantly decreased the DFT regardless of the pulse waveform (dofetiiide: from −18%± 19% to −24%± 19%, MS‐551: from −18%± ll% to −32%± 6%). In all drug groups, waveform related differences in DFT remained significant. These results support the view that the advantages of biphasic shock waveforms are not lessened by treatment with antiarrhythmic drugs.