Prognostic significance of serial P wave signal-averaged electrocardiograms following external electrical cardioversion for persistent atrial fibrillation: a prospective study.
The authors hypothesized that the persistence of abnormal atrial conduction detected by serial P wave signal-averaged electrocardiograms (P-SAECGs) can identify patients who are at high risk of recurrent atrial fibrillation (R-AF) following electrical cardioversion (ECV). P-SAECGs were recorded in 60 consecutive patients after ECV (53 men, age 66 +/- 10 years) and repeated in those who had remained in sinus rhythm (SR) 1 week, and 1, 3, and 6 months later. Filtered P wave duration (PD), root mean square (RMS) voltage of the terminal 40, 30, 20 ms (RMS-40, RMS-30, RMS-20) of the filtered P wave, RMS voltage of the entire filtered P wave (RMS-p), and the integral of the voltages in the entire P wave (integral-p) were analyzed. Thirty-one (52%) patients returned to AF within 1 week, an additional 11 (18%) by 1 month, and a further 2 (3.3%) at each subsequent assessment (3 and 6 months). The patients with R-AF had longer PD (157 +/- 24 vs 143 +/- 17 ms, P < 0.0001) and lower RMS-40, RMS-30, RMS-20 (5.3 +/- 2.0 vs 6.1 +/- 3.4 microV, P = 0.007; 4.3 +/- 1.5 vs 5.7 +/- 3.2 microV, P < 0.0001; 3.6 +/- 1.4 vs 5.2 +/- 3.0 microV, P < 0.0001, respectively) than those who remained in SR. These measurements did not change significantly in either group. RMS-p increased in SR patients (P = 0.009) but decreased in those who subsequently reverted to AF (P = 0.032) with a significant difference between the slopes of the RMS-p change (P = 0.006). Integral-p decreased from the time of ECV in the R-AF group only (P = 0.0028) and created a significant difference between the two slopes (P = 0.0004). The evolution of P-SAECG parameters after ECV differs in patients whose AF recurs versus patients who remain in SR.
Guo
Xiao Hua
XH
Department of Cardiological Sciences, St. George's Hospital Medical School, Cranmer Terrace, London SW17 0RE, U.K. xguo@sghms.ac.uk
Gallagher
Mark Michael
MM
Poloniecki
Jan
J
Yi
Gang
G
Camm
A John
AJ
D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000628:therapy*; D004554:Electric Countershock; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D012008:Recurrence; D012307:Risk Factors; D012815:Signal Processing, Computer-Assisted