Related Experiment Videos
Changes in atrial electrical properties following cardioversion of chronic atrial fibrillation: relation with
E G Manios1, E M Kanoupakis, G I Chlouverakis
1Department of Cardiology, University Hospital of Heraklion, Crete, Heraklion, Greece.
Insights
Atrial electrical remodeling reverses within 24 hours after cardioversion, but P wave duration normalizes more slowly. Higher post-conversion monophasic action potential duration predicts recurrence in chronic atrial fibrillation patients.
Area of Science:
- Cardiology
- Electrophysiology
- Atrial Fibrillation Research
Background:
- Chronic atrial fibrillation (CAF) is associated with electrical remodeling.
- Understanding the reversibility of this remodeling is crucial for managing post-conversion outcomes.
Purpose of the Study:
- To investigate the reversibility of atrial electrical remodeling after cardioversion in CAF patients.
- To determine the relationship between reversed remodeling and recurrence of atrial fibrillation.
Main Methods:
- 28 CAF patients converted to sinus rhythm had electrophysiological parameters measured: effective refractory period (ERP), monophasic action potential duration at 90% repolarization (MAPd90), and P wave duration.
- Measurements were taken at 5-20 min, 24 h, and 1 month post-conversion.
- A control group of 15 individuals without AF history was included for comparison.
- Patients were followed for 1 month for recurrence.
Main Results:
- Effective refractory period (ERP) and MAPd90 normalized to control levels within 24 hours post-conversion.
- P wave duration showed slower shortening, reaching control levels by 1 month.
- Abnormal rate adaptation of MAPd90 was observed only in the immediate post-conversion period.
- Higher MAPd90 values at 350 ms cycle length post-conversion predicted a higher likelihood of relapse (P<0.005).
Conclusions:
- Atrial electrical remodeling, specifically ERP and repolarization, is rapidly reversible within 24 hours of cardioversion.
- P wave duration normalizes more gradually over a month.
- Post-conversion MAPd90 measurements provide valuable prognostic information regarding recurrence risk in CAF patients.
Objective:
To study the reversibility of atrial electrical remodeling and its relation with recurrence in post-conversion chronic atrial fibrillation (CAF) patients.
Methods:
In 28 drug-free CAF patients (mean AF duration 41+/-39 months) electrically converted to sinus rhythm effective refractory period (ERP) at 500 ms, monophasic action potential at 90% of repolarization (MAPd90) at five cycle lengths (CL, 350, 400, 450, 500, 600 ms), and P wave duration were measured three times: within the interval 5-20 min post-conversion, 24 h and 1 month later. Fifteen subjects with no history of AF and normal atrial structure served as a control group. Patients were followed up for recurrence for 1 month; 12 relapsed.
Results:
ERP changed from 205+/-20 to 243+/-31 to 241+/-24 ms (P<0. 001), attaining a level comparable to that of the controls (238+/-21 ms) within 24 h. MAPd90 significantly (P<0.001) increased (from 175+/-11 to 190+/-19 to 191+/-10 ms at CL 350 ms and 201+/-12 to 234+/-20 and 233+/-23 ms at CL 600 ms) also reaching control levels within 24 h. MAPd90 exhibited an abnormal adaptation to rate only in the first evaluation. P wave duration was prolonged (137+/-33 ms) and exhibited a slower course of shortening (130+/-32 to 123+/-27 ms, P<0.001), reaching control levels within 1 month. Patients with higher values of MAPd90 at CL 350 in the immediate post-conversion period were more likely to relapse (P<0.005).
Conclusions:
ERP and repolarization shortening as a result of CAF are reversed within 24 h after conversion, while P wave duration reduces more slowly. Post-conversion MAPd90 values contain prognostic information for recurrence.