Circulation, Vol 73, 1029-1036, Copyright © 1986 by American Heart Association
PM Holt and EG Boyd
Ablation of atrioventricular conduction is now widely accepted in the
management of supraventricular arrhythmias. Reports of high temperatures,
high pressures, and gas production suggest that there may be adverse
effects on the blood, the electrode, and the cardiovascular system. In this
investigation, using samples of fresh, heparinized pig blood, we measured
hemolytic damage, the liberated gas volume and composition, and electrode
erosion associated with high-energy electrical ablation. The blood was
tested in a 10 liter tank at room temperature. Impulses of 10 to 400 J were
applied to new USCI No. 6F bipolar pacing electrodes using both positive
and negative polarities. Voltage and current waveforms were recorded. The
volume of gas liberated with cathodal electrodes was 0.50 microliter/J up
to 50 J and 0.29 microliter/J above 100 J. It was composed predominantly of
hydrogen and nitrogen, with carbon dioxide and oxygen. With positive
electrodes, the gas volume was linearly related to energy at 4.34
microliter/J up to 200 J and also contained carbon monoxide. The hemolysis
was directly proportional to impulse energy for both cathodal and anodal
electrodes, being 1.37 microliter/J and 4.48 microliters/J, respectively.
Electrode erosion was substantial but clinically acceptable. We conclude
that there are marked differences in the energy conversion processes and,
where the same energy can achieve a comparable clinical effectiveness,
there are advantages in using a cathodal electrode polarity. It is also
advisable to use lower energies.
ARTICLES
Hematologic effects of the high-energy endocardial ablation technique