title: Catheter ablation of mitral isthmus ventricular tachycardia using electroanatomically guided linear lesions.
abstract: Mitral isthmus ventricular tachycardia uses a reentrant circuit with a critical isthmus of conduction bounded by the mitral valve proximally and a remote inferior infarction scar distally. Successful catheter ablation requires placement of a lesion to transect the isthmus so as to prevent wavefront propagation. We report a case with previously unsuccessful ablation in which focal isthmus ablation failed to eliminate arrhythmia. Electroanatomic mapping demonstrated a wide tachycardia isthmus, and a linear lesion placed from the edge of the inferior infarct (as demonstrated on the three-dimensional voltage electroanatomic map) to the base of the mitral valve successfully eliminated tachycardia. In some patients with mitral isthmus VT, a wide isthmus requires linear lesion placement to fully transect the isthmus and eliminate tachycardia. Electroanatomic mapping can be used to define isthmus boundaries and thus guide successful ablation.
authors.affiliation: Division of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA. pfriedman@mayo.edu
authors.forename: P A
authors.initials: PA
authors.lastname: Friedman
authors.forename: D L
authors.initials: DL
authors.lastname: Packer
authors.forename: S C
authors.initials: SC
authors.lastname: Hammill
mesh_terms: D018780:Body Surface Potential Mapping / Q000379:methods*; D017115:Catheter Ablation / Q000379:methods*; D006329:Heart Conduction System / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve; D009203:Myocardial Infarction / Q000150:complications; D017180:Tachycardia, Ventricular / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*