title: Atrioventricular block after transcatheter balloon expandable aortic valve implantation.
abstract: OBJECTIVE
  Transcatheter aortic valve replacement (AVR) is a promising approach to aortic valve disease. The implications of this new therapy are not entirely known. We describe the potential for the development of new atrioventricular (AV) block.
  
  
  BACKGROUND
  Atrioventricular block is a known complication of conventional surgical AVR. Block is presumed to occur as a consequence of surgical trauma to the cardiac conduction tissue during excision of the diseased aortic valve and débridement of the calcified annulus. Whether AV block might occur as a consequence of nonsurgical implantation of an aortic stent valve is unknown.
  
  
  METHODS
  We reviewed our experience with patients undergoing transcatheter AVR using both the percutaneous transarterial and the open-chest direct left ventricular apical ventriculotomy approaches. Patients were considered at high risk for conventional surgery because of comorbidities. Continuous arrhythmia monitoring was performed for at least 48 h after the valve implantation procedure. Patients who developed apparently new, clinically significant AV block were identified.
  
  
  RESULTS
  Transcatheter AVR was successfully performed in 123 patients. Seventeen of these patients (13.8%) had pre-existing permanent pacemakers. Two patients (1.6%) required pacemaker implantation because of pre-existing intermittent bradycardia. Seven patients (5.7%) developed new and sustained complete AV block requiring pacemaker implantation. An additional 4 patients (3.3%) developed new and sustained left bundle branch block but did not require pacemaker implantation.
  
  
  CONCLUSIONS
  As with conventional AVR surgery, transcatheter AVR may result in impaired atrioventricular conduction. Physicians and patients should be aware of the potential for AV block and pacemaker dependence.
authors.affiliation: Heart Centre, St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Ajay
authors.initials: A
authors.lastname: Sinhal
authors.forename: Lukas
authors.initials: L
authors.lastname: Altwegg
authors.forename: Sanjeevan
authors.initials: S
authors.lastname: Pasupati
authors.forename: Karin H
authors.initials: KH
authors.lastname: Humphries
authors.forename: Michael
authors.initials: M
authors.lastname: Allard
authors.forename: Paul
authors.initials: P
authors.lastname: Martin
authors.forename: Anson
authors.initials: A
authors.lastname: Cheung
authors.forename: Jian
authors.initials: J
authors.lastname: Ye
authors.forename: Charles
authors.initials: C
authors.lastname: Kerr
authors.forename: Sam V
authors.initials: SV
authors.lastname: Lichtenstein
authors.forename: John G
authors.initials: JG
authors.lastname: Webb
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000628:therapy*; D054537:Atrioventricular Block / Q000209:etiology* / Q000473:pathology / Q000628:therapy; D001919:Bradycardia / Q000209:etiology; D006328:Cardiac Catheterization / Q000009:adverse effects* / Q000295:instrumentation; D002304:Cardiac Pacing, Artificial; D002404:Catheterization / Q000009:adverse effects*; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial; D011446:Prospective Studies; D012720:Severity of Illness Index