Ion Channel Remodeling Is Related to Intraoperative Atrial Effective Refractory Periods in Patients With Paroxysmal and Persistent Atrial Fibrillation
Population
42 patients, including those with paroxysmal or persistent atrial fibrillation, and controls in sinus rhythm.
Design
Case-control
Authors
Discussion
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Member takes
Implication
May link channel loss to AERP shortening in AF; hypothesis-generating and requires prospective validation before therapeutic targeting.
Key Points
- Investigate the relationship between ion channel expression (L-type calcium and potassium channels) and atrial effective refractory periods in patients with paroxysmal and persistent atrial fibrillation.
- Analyzed mRNA via RT-PCR and protein expression via slot-blot in atrial appendages from patients with paroxysmal AF (n=13), persistent AF (n=16), and sinus rhythm controls (n=13).
- Measured intraoperative atrial effective refractory periods (AERP) across five basic cycle lengths between 250 and 600 ms.
- Protein expression for the L-type Ca2+ channel and five potassium channels (Kv4.3, Kv1.5, HERG, minK, Kir3.1) was significantly reduced in both paroxysmal and persistent AF, whereas mRNA levels were decreased primarily in persistent AF.
- AERPs were significantly shorter in paroxysmal and persistent AF, with ion channel protein levels correlating positively with AERP duration and rate adaptation.
Structured PICO
P
Population
42 patients, including those with paroxysmal (n=13) or persistent (n=16) atrial fibrillation, and controls in sinus rhythm (n=13).
C
Comparator
Controls in sinus rhythm (n=13)
O
Outcome
mRNA and protein expression of L-type calcium channel and potassium channels in left and right atrial appendages, and intraoperative atrial effective refractory periods (AERP)surrogate
Reductions in L-type calcium and potassium channel proteins correlate with shortened atrial effective refractory periods, explaining electrophysiological remodeling in atrial fibrillation.
Cite This Study
Brundel et al. (2001) studied this question.