Assessment of cardiac arrhythmias in patients with ankylosing spondylitis by signal-averaged P wave duration and P wave dispersion.

Objective: Aortic regurgitation, conduction disturbances, increased myocardial fibrosis and pericarditis could be seen in ankylosing spondylitis (AS). However, less attention has been paid to supraventricular arrhythmias (SVA) and atrial conduction system changes. We aimed to assess SVA and conduction system changes in patients with AS.

Patients And Methods: Twenty-eight patients (24 men; mean age, 28.7 ± 5.7 years) with AS and 30 healthy volunteers (26 men; mean age, 29.3 ± 5.8 years) were enrolled. All subjects were evaluated by 24-hour ambulatory electrocardiogram, 12 lead standard electrocardiogram (ECG) for P wave dispersion (Pd), and signal-averaged ECG (SAECG) for P wave duration (SAPWD).

Results: SVAs were detected in 9 patients with AS (32%) and 3 controls (10%; p =0.02). Mean SAPWD (115.7±28.6 ms vs. 100.2 ± 18.7 ms, p =0.017) and mean Pd (11.9±4.8 ms vs. 9.3±3.6 ms, 0.023) was longer in patients with AS than the control group. When patient with AS were divided into 2 subgroups as patients with or without SVA, the Pd (16.2±5.0 vs. 9.9±3.2, p =0.001), SAPWD (151.4±7.8 vs. 98.7±16.1, p =0.001) and Bath ankylosing spondylitis disease activity index (BASDAI) (5.1±1.6 vs. 3.7±1.0, p =0.014) were significantly greater in the subgroup with arrhythmias compared to the subgroup without arrhythmias. There was a moderate positive correlation between BASDAI and SAPWD (r=0.622, p =0.001). There was also a moderate positive correlation between BASDAI and Pd (r=0.479, p =0.01).

Conclusions: SVA were detected more frequently in AS than control group. SAPWD and Pd were prolonged in patients with AS. Clinical severity assessed with BASDAI had a positive correlation with prolongation of SAPWD and Pd.