Cor Vasa 2003, 44(3):135-139
Late atrial potentials in patients after cardioversion of atrial fibrillation of different duration
- Klinika kardiologie, Institut klinické a experimentální medicíny, Praha, Česká republika
Aim:
A prolonged P wave duration when using signal-averaged high-resolution ECG (P-SAECG) may indicate the presence of impaired intra- and interatrial conduction, which could be a factor predisposing to atrial fibrillation (AF). The aim of the study was to evaluate changes in P-SAECG in patients undergoing cardioversion of AF different duration.
Methods:
We evaluated 26 patients (20 males, age 62 ± 14y) after successful cardioversion (CV) of symptomatic acute AF persistent less than 48 hours (group A) and 42 patients (33 males, age 61 ± 13y) after CV of persistent symptomatic AF of duration of more than 1 month (group B). A control group included 21 healthy subjects (11 males, 62 ± 11y) without organic cardiac disease and a history of AF. We measured the filtered P wave duration, the root mean square voltage in terminal 20 ms of the P wave (RMS 20) using analysis of three orthogonal ECG leads (MAC 5000, Marquette, USA); the signal was passed through a bandpass filter (40-250 Hz). The left atrial diameter and left ventricular ejection fraction (LVEF) were evaluated by 2D echocardiography.
Results:
P-wave duration was 143.3 ± 19.3 ms in group A, and 171.7 ± 46.5 ms in group B (p < 0.001). The left atrial diameter was 38.9 ± 5.7 mm in group A, and 45.2 ± 6.5 mm in group B (p < 0.001). There were no statistical differences in RMS 20 as well as in LVEF between groups A (3.7 ± 2.8 ms) and B (3.1 ± 1.7 ms). The filtered P-wave duration in group B (171.7 ± 46.5 ms) was significantly longer than in the control group (128.0 ± 15.8 ms, p < 0.001). No significant differences were seen between group A and the control group.
Conclusion:
The significant prolongation of P-wave duration in P-SAECG after a prolonged period of symptomatic AF may possibly reflect atrial electrophysiological remodeling caused by this arrhythmia. Anatomical remodeling is probably represented by the significantly greater LAD in patients with prolonged AF duration.
Keywords: Late atrial potentials; Atrial fibrillation; Cardioversion; ECG
Published: March 1, 2003 Show citation