Alternans of Atrial Action Potentials During Atrial Flutter as a Precursor to Atrial Fibrillation
Key result
Overdrive pacing-induced action potential alternans at the isthmus occurred in all patients who developed atrial fibrillation compared to 50% of those who did not (P<0.0003).
Why the study?
Does overdrive pacing induce action potential alternans at the isthmus preceding the transition from atrial flutter to atrial fibrillation in patients with typical atrial flutter?
Population
38 patients with typical atrial flutter (Afl)
Design
Cohort
Authors
Discussion
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Member takes
Implication
May flag AF transition risk during flutter ablation; hypothesis-generating for isthmus-targeted strategies.
Study Design
Type
Observational (n=38)
Structured PICO
Does overdrive pacing induce action potential alternans at the isthmus preceding the transition from atrial flutter to atrial fibrillation in patients with typical atrial flutter?
P
Population
38 patients with typical atrial flutter (Afl)
I
Intervention
Overdrive pacing to 160 ms or to the initiation of atrial fibrillation (AF), with monophasic action potential (MAP) recordings at the isthmus and high or low right atrium
O
Outcome
Occurrence of monophasic action potential (MAP) alternans and transition to atrial fibrillation (AF)surrogate
Main Result
Absolute Event Rate: 100% vs 50%
p-value: p=<0.0003
Action potential duration alternans and conduction block at the isthmus precede the transition from typical atrial flutter to atrial fibrillation, providing a mechanistic rationale for the efficacy of isthmus ablation in preventing AF recurrence.
Cite This Study
Narayan et al. (2002) conducted an observational in Typical atrial flutter (n=38). Overdrive pacing vs. Patients who did not develop atrial fibrillation was evaluated on Occurrence of monophasic action potential alternans (p=<0.0003). Overdrive pacing-induced action potential alternans at the isthmus occurred in all patients who developed atrial fibrillation compared to 50% of those who did not (P<0.0003).