| Autor: |
Weiss DN; Department of Medicine, University of Maryland Medical System, Baltimore, USA., Shorofsky SR, Peters RW, Gold MR |
| Jazyk: |
angličtina |
| Zdroj: |
Journal of interventional cardiac electrophysiology : an international journal of arrhythmias and pacing [J Interv Card Electrophysiol] 1998 Sep; Vol. 2 (3), pp. 273-7. |
| DOI: |
10.1023/a:1009745222443 |
| Abstrakt: |
The impedance of internal defibrillator shocks is an important determinant of defibrillation efficacy. To assess the effect of delivered energy on impedance, we studied 97 patients with 4 different lead systems. The lead systems evaluated were two epicardial patches, a hybrid system of a patch and right atrial coil, a dual coil transvenous lead and a transvenous lead with a subcutaneous patch. Impedances were measured for 6 shock energies between 0.1 and 30 J. Shock impedance increased at low energies for all lead systems (p < 0.001), although the rate of increase varied markedly between systems. The energy factor (FE), which is the ratio of impedances for the 0.1 and 10 J shocks, was least for the platinum transvenous lead (1.2 +/- 0.02) and greatest for the titanium hybrid lead (4.2 +/- 0.2). Reversing the polarity of the hybrid lead markedly attenuated the impedance rise. These findings indicate that there is at least a modest rise (20%) of shock impedance at very low delivered energies. The largest increases noted with titanium lead systems are primarily due to polarization. Titanium transvenous leads should be avoided when low energy shocks are utilized such as for the cardioversion of ventricular tachycardia or atrial fibrillation. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
|
Full text from SpringerLink