Arrhythmias & electrophysiologyResearch article
The irregularity factor: Mechanistic insights into beat-to-beat irregularities in atrial fibrillation cycle length
- Mapping was performed in 24 patients with long-standing persistent atrial fibrillation (AF) (long-standing persistent AF (LSPAF)) and a reference group
Authors' conclusion
The IF indicates the underlying complexity of activation patterns, is higher during LSPAF than during acute AF, and is comparable throughout the atria during LSPAF. It is a novel, easy-to-calculate, objective electrical biomarker, which can be used for, for example, guiding patient-tailored treatment independently of the AF mechanisms.
Study context
- Population
- Patients with long-standing persistent AF (LSPAF) and a reference group of patients with induced (acute) AFLSPAF 24 · reference group (induced [acute] AF) 25
- Participants
- 24 vs 25
- Comparison
- LSPAF vs acute AF
- LSPAFn = 24
- acute AFn = 25
Main finding
As reported in the abstract
LSPAF
52
± 17
acute AF
25
± 10
P < 0.001
Further findings
Δ-CTs · larger during LSPAF
P = 0.005
Beat-to-beat changes in conduction velocity
P = 0.001
Beat-to-beat changes in path length · comparable
P = 0.333
| Outcome | LSPAF | acute AF | P value |
|---|---|---|---|
| Beat-to-beat changes in direction | 94° ± 13° | 64° ± 22° | P < 0.001 |
Correlation of irregularity factor (IF) with activation pattern complexity
- conduction block
- ρ = 0.887
- lines of conduction block lengths
- ρ = 0.900
- number of fibrillation waves
- ρ = 0.889
- prevalence of focal waves
- ρ = 0.609
- P < .001 for all
Original publication
Summarised from the published abstract; every number is checked against it