Author + information
- Received August 25, 1986
- Revision received December 19, 1986
- Accepted January 9, 1987
- Published online August 1, 1987.
- Jule N. Wetherbee, MD1,
- Peter D. Chapman, MD, FACC1,*,
- H. Sidney Klopfenstein, MD, PhD1,
- Stanley M. Bach Jr., MD1 and
- Paul J. Troup, MD, FACC1
- ↵*Address for reprints:Peter D. Chapman, MD, Division of Cardiology, Medical College of Wisconsin, 8700 West Wisconsin Avenue, Milwaukee, Wisconsin 53226.
The efficacy of truncated exponential waveform shocks using a cardioverter-defibrillator catheter with and without a 13.9 cm2 subcutaneous thoracic patch electrode was examined in 10 pentobarbital-anesthetized dogs. The cardioverter-defibrillator catheter was positioned through the external jugular vein with the distal 4 cm2 shocking electrode located in the right ventricular apex and the 8 cm2 proximal electrode located in the superior vena cava. Four electrode configurations were tested: 1) distal electrode (cathode) to proximal electrode apd chest wall patch (common anodes), 2) distal electrode (cathode) to chest wall patch (anode), 3) distal electrode (cathode) to proximal electrode (anode), and 4) chest wall patch (cathode) to proximal electrode (anode). The lowest randomized energy resulting in termination of alternating current-induced ventricular fibrillation on four trials at that energy was 20.2,21.3,27.4 and >40 J, respectively, for configurations 1 through 4.
The energy requirements for configurations 1, 2 and 3 were significantly lower than for configuration 4 (p < 0.001). Additionally, configurations incorporating the distal electrode and the patch electrode (configurations 1 and 2) were significantly better than the catheter alone (configuration 3; p < 0.05). There was no significant difference between configurations 1 and 2.
In conclusion, the addition of a subcutaneous chest wall electrode to the cardioverter-defibrillator catheter significantly lowered energy requirements for defibrillation, suggesting that a nonthoracotomy approach for the automatic implantable cardioverter-defibrillator is feasible.
with the technical assistance of CATHLEEN A. McDOWELL
- Received August 25, 1986.
- Revision received December 19, 1986.
- Accepted January 9, 1987.
- American College of Cardiology Foundation