Left Atrial Appendage (LAA): An Under-Recognized Trigger Site of Atrial Fibrillation
Recurrence of A-Fib after an ablation is very disappointing and frustrating both for patients and for EPs performing the ablation.
A link to the source of A-Fib recurrence may have been found. A study by Dr. Di Biase and his colleagues established that the LAA is responsible for a great deal of A-Fib recurrence.
Research: LAA Responsible for 27% of Recurrences
The multi-center study enrolled patients at leading medical centers in Austin, Texas, San Francisco and Palo Alto, Calif, Rome and Venice, Italy, Cleveland and Akron, Ohio.
In the study of 987 patients undergoing redo catheter ablations, 266 (27%) showed a prevalence of A-Fib triggers firing from the LAA.
In 32+% of these 266 patients, the LAA was the only source of arrhythmia signals.
Trial Design of LAA for Recurrences
The 266 patients were divided into three groups with different treatments. Each group was followed for 12+ months with these results:
- Group 1. The LAA was not ablated (isolated); 74% of this group had recurrences of A-Fib.
- Group 2. The LAA was ablated with focal lesions. 68% of this group had recurrences of A-Fib.
- Group 3. The LAA was ablated by a circular catheter at the ostium of the LAA. 15% of this group had recurrences of A-Fib.
Trial Findings: LAA Responsible for Much A-Fib
While this study was limited, as it only looked at redo ablations and recurrences, it’s significant. The patients (Group 3) who were ablated by a circular catheter at the ostium of the LAA, had a recurrence rate of only 15%!
Compared to 68% and 74%, this is a major, significant reduction in recurrences. This is great news for A-Fib patients undergoing a catheter ablation.
Trial results indicate that the LAA is responsible for a great deal of arrhythmia signals, probably more than any other area of the heart.
A-Fib Ablations: Check LAA for Non-PV Signals
Many EPs today aren’t aware of the importance of the LAA as a source of A-Fib signals and never even look at the LAA when doing an ablation. In the words of the study’s authors, “the LAA is an underestimated site of initiation of atrial fibrillation.”
It’s good news that an increasing number of EPs after performing a PVI, then as their second step, map and ablate the LAA. This is especially in cases of persistent A-Fib and those with non-PV triggers. After the PVs are isolated, the LAA should be the next place to look. (Make sure your EP is one those who check the LAA!)
What This Means to Ablation Patients
This research is important not just for patients undergoing a redo catheter ablation but for any A-Fib patient seeking a catheter ablation.
Important when selecting your EP: When having a catheter ablation, no matter what kind of A-Fib you have, make sure your EP knows how, is experienced at, and routinely maps and ablates the LAA.
This may produce a more successful ablation and save you from a recurrence of A-Fib.
To learn more about the Left Atrial Appendage, see my article, The Role of the Left Atrial Appendage (LAA) & Removal Issues.