Catheter ablation guided by termination of postinfarction ventricular tachycardia by pacing with nonglobal capture.
OBJECTIVE
We prospectively investigated the prevalence and value of this criterion for identifying a target site for ablation in patients with postinfarction ventricular tachycardia (VT).


BACKGROUND
Termination of postinfarction VT by pacing with nonglobal capture identifies a critical component of the reentrant circuit.


METHODS
In a consecutive series of 34 patients with prior infarction (age 67 +/- 10 years, ejection fraction 0.26 +/- 0.1) referred for radiofrequency catheter ablation, mapping was performed in the left ventricle. At sites with abnormal electrograms, pacing was performed during VT. If VT terminated with nonglobal capture during the pacing train, radiofrequency energy was delivered.


RESULTS
Sixty-two VTs (cycle length 450 +/- 84 ms) were mapped and targeted for radiofrequency ablation. Concealed entrainment was present at 101 endocardial sites. Among the 101 sites, VT terminated by pacing with nonglobal capture at 5 sites (5%). At 10 additional sites in 10 patients, VT terminated by pacing with nonglobal capture, and concealed entrainment could not be documented at these sites because of reproducible termination of the VT. An application of radiofrequency energy resulted in VT termination at all 15 sites where nonglobal capture was documented and the targeted VTs were no longer inducible after ablation.


CONCLUSIONS
Termination of VT by pacing with nonglobal capture can be demonstrated in approximately one third of patients with postinfarction VT and is a specific criterion for identifying a critical component of the reentrant circuit, whether or not concealed entrainment can be documented at that site.
Bogun
Frank
F
University of Michigan, Ann Arbor, 48109, USA. fbogun@umich.edu
Krishnan
Subramaniam C
SC
Marine
Joseph E
JE
Hohnloser
Stefan H
SH
Schuger
Claudio
C
Oral
Hakan
H
Pelosi
Frank
F
Chugh
Aman
A
Morady
Fred
F
D000368:Aged; D002304:Cardiac Pacing, Artificial; D017115:Catheter Ablation / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000503:physiopathology*; D015995:Prevalence; D011446:Prospective Studies; D017180:Tachycardia, Ventricular / Q000628:therapy*