September 2, 1997Circulation
Effect of Verapamil and Procainamide on Atrial Fibrillation–Induced Electrical Remodeling in Humans
Why the study?
Does verapamil or procainamide prevent atrial fibrillation-induced electrical remodeling (ERP shortening) in adult patients without structural heart disease?
Population
47 adult patients without structural heart disease
Comparison
Verapamil or procainamide administered after… vs Saline administered after pharmacological…
Design
Cohort
Follow-up
Immediate (acute)
Authors
Discussion
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Member takes
Implication
Supports calcium loading in acute AF remodeling; hypothesis-generating and should not yet change practice.
Key Points
- Evaluate whether verapamil or procainamide prevents acute atrial fibrillation-induced electrical remodeling and refractory period shortening in humans.
- Assessed 47 adult patients without structural heart disease given autonomic blockade followed by verapamil (n=17), procainamide (n=10), or saline (n=20).
- Paced the atria rapidly to induce fibrillation, then measured pre- and post-fibrillation atrial effective refractory periods at 350-ms and 500-ms drive cycle lengths.
- Saline controls exhibited marked shortening of the atrial effective refractory period at 350 ms (206±19 to 179±27 ms, P<0.0001) and 500 ms (217±16 to 183±23 ms, P<0.0001), with similar shortening occurring in the procainamide group.
- Verapamil prevented post-fibrillation refractory period shortening at both 350 ms (226±15 vs 227±22 ms, P=0.8) and 500 ms (230±17 vs 232±20 ms, P=0.6).
- Secondary atrial fibrillation episodes occurred during refractory period testing in 12% of verapamil patients versus 90% of saline and 80% of procainamide patients (P<0.01 vs verapamil).
Structured PICO
Does verapamil or procainamide prevent atrial fibrillation-induced electrical remodeling (ERP shortening) in adult patients without structural heart disease?
P
Population
47 adult patients without structural heart disease
I
Intervention
Verapamil or procainamide administered after pharmacological autonomic blockade
C
Comparator
Saline administered after pharmacological autonomic blockade
O
Outcome
Change in atrial effective refractory period (ERP) before and after atrial fibrillation induced by rapid pacingsurrogate
Pretreatment with the calcium channel antagonist verapamil, but not procainamide, attenuates acute AF-induced electrical remodeling, suggesting a role for calcium loading in this process.
Cite This Study
Daoud et al. (1997) studied this question.