Dissociation of the site of origin from the site of cryo-termination of ventricular tachycardia.
We performed conventional electrogram mapping and cryomapping in dogs with one-week-old experimentally-induced myocardial infarctions and programmed stimulation-induced sustained ventricular tachycardias to assess whether there is a correlation between the "site of origin" and site of cryo-termination of ventricular tachycardia (VT). Electrogram maps showed that 4 of 8 induced sustained VTs were due to macro- and 4 of 8 to microre-entry. Local cooling of the site of origin terminated 4 of 4 microre-entrant VTs, but only 1 of 4 macrore-entrant VTs. In the other 3 macrore-entrant VTs, the sites of cryo-termination were 2, 2.5, and 4 cm distant from the sites of origin. In contrast, cooling of the mid-to-late diastolic portions of the re-entry loops terminated all 8 VTs. These data demonstrate a dissociation of the site of origin from the site of cryo-termination of macrore-entrant VT.
D000818:Animals; D003080:Cold Temperature; D003452:Cryosurgery / Q000379:methods*; D004195:Disease Models, Animal; D004285:Dogs; D004558:Electric Stimulation / Q000379:methods; D004594:Electrophysiology / Q000379:methods; D005615:Freezing; D007053:Ice; D009203:Myocardial Infarction / Q000503:physiopathology; D013610:Tachycardia / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000601:surgery
D007053:Ice