Feasibility of targeting catheter ablation to the markedly low-voltage area surrounding infarct scars in patients with post-infarction ventricular tachycardia.
BACKGROUND
In routine substrate mapping of the left ventricle, an abnormal area is defined as having an amplitude <1.5 mV. However, that is usually too large for catheter ablation in post-infarction ventricular tachycardia (VT) and the use of strict voltage criteria may produce better outcomes.


RESULTS
Twenty patients with post-infarction VT underwent substrate mapping using an electroanatomic mapping system. Strict voltage criteria were defined as: non-arrhythmogenic area, >0.6 mV; low-voltage area (LVA), >0.1 to <or=0.6 mV; scar, <or=0.1 mV. Radiofrequency applications targeted the LVA only, which was 48+/-26 cm(2), 55% smaller than that of the generally targeted area with an amplitude <or=1.5 mV. The prevalence of delayed electrograms (duration >or=150 ms) was significantly higher in the LVAs than in the border areas with an amplitude of >0.6 to <or=1.5 mV (33.2% vs 3.7%, p<0.001). With the exception of 2 instances of peri-mitral VT, all VT isthmuses resided within the LVA. During follow-up of 24+/-13 months, 16 patients (80%) have been free of any VT episodes.


CONCLUSIONS
Catheter ablation targeting LVAs with an amplitude <or=0.6 mV appears to be useful for efficient and effective treatment of post-infarction VT.
Yoshida
Kentaro
K
Cardiovascular Division, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8575, Japan. kentaroyo@nifty.com
Sekiguchi
Yukio
Y
Tanoue
Kazuyuki
K
Endo
Masae
M
Suzuki
Akihiro
A
Kanemoto
Miyako
M
Yamasaki
Hiro
H
Yamauchi
Yasuteru
Y
Takahashi
Atsushi
A
Kuga
Keisuke
K
Yamaguchi
Iwao
I
Aonuma
Kazutaka
K
D000368:Aged; D018780:Body Surface Potential Mapping / Q000379:methods*; D017115:Catheter Ablation / Q000379:methods*; D004562:Electrocardiography; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000175:diagnosis* / Q000601:surgery*; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000209:etiology / Q000601:surgery*; D016896:Treatment Outcome