title: Induction of transient third degree atrioventricular block during radiofrequency catheter ablation in a patient with ventricular tachycardia and remote myocardial infarction.
abstract: BACKGROUND
  Radiofrequency catheter ablation has been demonstrated to be an effective and safe therapy in patients with so-called idiopathic ventricular tachycardia, whereas the benefit/risk profile for ablation of ventricular tachycardia in patients with chronic myocardial infarction and severely compromised left ventricular function still needs to be determined. The present report describes the unintended induction of transient third-degree atrioventricular block in a patient with remote myocardial infarction who underwent radiofrequency catheter ablation of ventricular tachycardia.
  
  
  RESULTS
  Endocardial catheter mapping and radiofrequency ablation were performed in a 57-year-old patient with chronic recurrent ventricular tachycardia, who had previously suffered from anterior and posterior wall myocardial infarction. Additionally, the patient presented with complete right bundle branch block during sinus rhythm. Radiofrequency energy applied to a critical site of the reentrant tachycardia at the left ventricular basal septum during sinus rhythm induced third-degree atrioventricular block after 20 s of current delivery, which lasted for 24 h. At this site, a presumable left bundle branch potential was recorded during sinus rhythm.
  
  
  CONCLUSIONS
  Radiofrequency current application for ablation of ventricular tachycardia may induce third-degree atrioventricular block in patients with remote myocardial infarction. When current is delivered to target sites at the left ventricular basal septum, radiofrequency energy should be applied during sinus rhythm to allow continuous monitoring of atrioventricular conduction. Special caution should be given to patients with right bundle branch block during sinus rhythm.
authors.affiliation: Hospital of the Westfälische Wilhelms-University, Department of Cardiology and Angiology, Münster, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Kottkamp
authors.forename: X
authors.initials: X
authors.lastname: Chen
authors.forename: G
authors.initials: G
authors.lastname: Hindricks
authors.forename: S
authors.initials: S
authors.lastname: Willems
authors.forename: W
authors.initials: W
authors.lastname: Haverkamp
authors.forename: T
authors.initials: T
authors.lastname: Wichter
authors.forename: G
authors.initials: G
authors.lastname: Breithardt
authors.forename: M
authors.initials: M
authors.lastname: Borggrefe
mesh_terms: D017115:Catheter Ablation / Q000009:adverse effects*; D004562:Electrocardiography; D006327:Heart Block / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications*; D017180:Tachycardia, Ventricular / Q000150:complications / Q000601:surgery*