Introduction
Atrial fibrillation (AF), the most frequently encountered cardiac
arrhythmia,1 is associated with high mortality and
morbidity, mainly due to thromboembolic complications and heart failure.
In recent times, catheter ablation (CA) has been found to be effective
for treating AF.2,3 However, AF recurs after CA in
10–30% of patients,4.5 and few reports have focused
on the use of electrocardiography (ECG) for predicting AF recurrence
after CA.
Signal-averaged electrocardiography (SAECG) is a technique used for
recording microvolt-potentials from the body surface. QRS-SAECG is
commonly performed, and positive QRS-SAECG findings have been found to
be associated with fatal ventricular arrhythmias and sudden cardiac
death.6 In contrast, robust evidence on the use of
P-wave SAECG (P-SAECG) is lacking. Previous reports have demonstrated
that P-SAECG findings of atrial late potentials (ALP) could be
indicative of atrial fibrosis, an arrhythmogenic substrate, in patients
with AF. Therefore, P-SAECG could be useful for identifying patients at
risk of developing new-onset AF7,8 and those in whom
conversion from paroxysmal to chronic AF is likely.9
We hypothesized that pre-recorded ALP would differ between patients with
and without AF recurrence after CA, and positive ALP would be associated
with AF recurrence.