Radiofrequency Catheter Ablation Of Purkinje System Involved Ventricular Tachycardia After Myocardial Infarction

ObjectiveTo report the mechanism and radiofrequency catheter ablation ofventricular tachycardia (VT) arising from the left posterior Purkinje fibers inpatients with a prior myocardial infarction (MI).MethodsThree patients were all males, and aged from55to75years old, withrecurrent episodes of VT after anterior MI (LVEF0.44～0.61) despiteantiarrhythmic drugs and/or revascularization were studied. The VT orpremature ventricular contractions(PVC) presented right bundle branchblock(RBBB) with left axis in3patients or right axis in1patient. CARTOelectroanatomic mapping system and saline irrigated radiofrequency catheterwere used for mapping and ablating VT/PVC.ResultsClinical sustained VT was reproducibly induced by programmedstimulation in2patients, and spontaneous clinical non-sustained VT/PVC wereobserved in1patient. Purkinje potentials (PP) or diastolic potentials(DP) weresequentially observed along the left ventricular posterior septum adjacent tothe low voltage area during the VT/PVC in all the3patients. The typicalmacro-reentrant VT around the MI scar could not be mapped in anyone of the3patients. Radiofrequency energy delivered at the site exhibiting aPP/DP–QRS interval of-20to-70ms successfully eliminated the VT/PVC. ConclusionsPurkinje system involved monomorphic VT after MI, which is analogous toidiopathic left VT, can develop in the acute or chronic phase of MI.Radiofrequency catheter ablation can effectively eliminate this VT withoutaffecting left ventricular conduction.