Author + information
- Received August 8, 2016
- Revision received September 6, 2016
- Accepted September 8, 2016
- Published online May 15, 2017.
- Idris Harding, MBBS, BSc,
- Rachel Bastiaenen, MA,
- Parisha Khan, BSc,
- Anna Marciniak, MD,
- Rajan Sharma, MD and
- Mark M. Gallagher, BSc, MD∗ ()
- Cardiology Clinical Academic Group, St. George’s University Hospitals NHS Foundation Trust, St George’s University of London, London, United Kingdom
- ↵∗Address for correspondence:
Dr. Mark M. Gallagher, Department of Cardiology, St. George’s Hospital, Blackshaw Road, London SW17 0QT, United Kingdom.
- atrial fibrillation
- atrial fibrillation ablation
- electrical isolation
- left atrial appendage
- transesophageal echocardiography
A 57-year-old woman presented with intermittent atrial tachycardia having had extensive ablation for persistent atrial fibrillation 2 years and 7 years earlier. On the first procedure, isolation of the pulmonary veins, a roof line and a mitral line were undertaken. On the second, the pulmonary veins were confirmed isolated from the prior procedure and ablation targeted an area of fractionation in the base of the left atrial appendage (LAA) as well as reinforcing the roof and mitral lines.
On admission to hospital she took no regular medication and electrocardiograph showed sinus rhythm with first-degree atrioventricular block. A transesophageal echocardiogram was performed under general anesthesia as the patient was being prepared for ablation. The LAA was found to be free of thrombus, but seemed to move in a rapid fluttering manner, confirmed by the Doppler flow pattern (Figure 1).
The left atrium was mapped electrically: an extensive area was found to be electrically silent including the roof, the posterior wall, and the pulmonary veins. Electrograms in the coronary sinus were delayed and of low amplitude. The LAA displayed rapid and sustained electrical activity, at times regular with a cycle length of 180 ms. At other times, the activity disorganized (Figure 2). Mapping of the posterior aspect of the LAA showed the electrical activity to be fractionated and more chaotic.
No left atrial arrhythmia was inducible by programmed stimulation. A right atrial tachycardia, apparently micro-reentrant in nature was induced and ablated. The patient has been advised to continue anticoagulant therapy for life regardless of the outcome of ablation.
The LAA is recognized as a leading nonpulmonary vein source of atrial fibrillation triggers, and electrical disconnection (1) or delay (2) of the LAA has been shown in small, randomized trials to reduce atrial fibrillation recurrence after ablation. Despite these encouraging results, concern persists that the isolated LAA will become immobile, fostering the development of thrombus and imparting increased stroke risk. The long-term outcome of LAA isolation will be evaluated in the BELIEF (Effect of Empirical Left Atrial Appendage Isolation on Long-term Procedure Outcome in Patients With Persistent or Long-standing Persistent Atrial Fibrillation Undergoing Catheter Ablation) trial (3).
In this patient, the isolation of the LAA occurred at some point in the first 2 years after an ablation. As the isolation was not recognized and the patient has a CHADSVASC score of only 1, no anticoagulation was used during this period with no apparent ill effect.
The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
All authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
- Received August 8, 2016.
- Revision received September 6, 2016.
- Accepted September 8, 2016.
- Di Biase L.,
- Burkhardt J.D.,
- Mohanty P.,
- et al.
- Park H.-C.,
- Lee D.,
- Shim J.,
- Choi J.-I.,
- Kim Y.-H.
- ↵National Institutes of Health. Effect of Empirical Left Atrial Appendage Isolation on Long-term Procedure Outcome in Patients With Persistent or Long-standing Persistent Atrial Fibrillation Undergoing Catheter Ablation 2014. Available at: https://clinicaltrials.gov/ct2/show/NCT01362738. Accessed December 20, 2016.