Laser photoablation of experimental post-infarction ventricular tachycardia guided by three dimensional activation mapping.
OBJECTIVE
The purpose of this study was to evaluate the efficacy of epicardially delivered laser energy to ablate induced ventricular tachycardia in a post-infarction canine model.


METHODS
In 13 canines, the left anterior wall myocardial infarction was created. Five days later, 240 plunged electrodes were inserted into the heart. Three-dimensional ventricular activation sequences were analyzed on line by a computerized mapping system.


RESULTS
Sixteen sustained monomorphic ventricular tachycardias were reproducibly induced in 10 canines. Epicardially contacted Nd:YAG laser irradiated the areas of the final pathway in macro-reentrant activation and the impulse origin in focal excitation. Linear photocoagulation lesions (11-16 x 50-72 mm) were created. Seven macro-reentrant circuits and six of nine focal origins were eliminated (success rate 81%). Pathology showed that laser photocoagulation involved all surviving subepicardial and intramural fibers.


CONCLUSIONS
Epicardially delivered laser energy in conjunction with electrical activation mapping has a high probability of ablating post-infarction ventricular tachycardia.
Wu
G
G
Laser and Applied Technologies Laboratory, Carolinas Medical Center, Charlotte, North Carolina 28232, USA.
Svenson
R H
RH
Littmann
L
L
Chuang
C H
CH
Thompson
M
M
Nanney
G A
GA
Splinter
R
R
Tatsis
G P
GP
Dezern
K R
KR
D000818:Animals; D004285:Dogs; D004553:Electric Conductivity; D004562:Electrocardiography; D005260:Female; D006346:Heart Septum / Q000473:pathology; D017075:Laser Coagulation; D008297:Male; D009203:Myocardial Infarction / Q000150:complications*; D017180:Tachycardia, Ventricular / Q000473:pathology / Q000601:surgery*