ISSN:
1741-0444
Keywords:
Current distribution
;
Electrical defibrillation
;
Finite-element model
;
Myocardial damage
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Abstract The present rationale for clinical defibrillation is empirically based, and the technique is the same for different paddle locations and anatomical configurations. Using a two-dimensional finite element model, we studied the effects of such variations on the distribution of myocardial current during defibrillation, and developed a method to quantitatively assess the potential for a defibrillating shock to cause myocardial damage. We used this method to compare five paddle placements, two paddle sizes and three variations of thoracic anatomy. Anatomical variations did not affect current distributions during electrical defibrillation, whereas paddle position had a marked effect. Paddle positions close to the heart with interposed bony structures between the heart and electrode produced focal regions of much higher than average myocardial current magnitudes. Myocytes in the highest current intensity regions dissipated 49 times the energy dissipated by cells exposed to threshold current magnitudes, potentially causing focal myocardial damage. An alternative paddle position was identified which significantly improved the myocardial current distribution. Maximum energy dissipation was only 4·8 times threshold energy, while defibrillation efficiency was reduced by 〈7 per cent, minimising the risk of myocardial damage. These results suggest that paddle position plays a dominant role in determining myocardial current distributions and defibrillation-induced damage.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02441640
