Evaluation of the P Wave Axis in Patients With Systemic Lupus Erythematosus

Introduction: p wave axis is one of the most practical clinical tool for evaluation of cardiovascular disease. the aim of our study was to evaluate the p wave axis in electrocardiogram (ecg), left atrial function and association between the disease activity score in patients with systemic lupus erythematosus (sle). methods: standard 12-lead surface ecgs were recorded by at a paper speed of 25 m/s and an amplifier gain of 10 mm/mv. the heart rate (hr), the duration of pr, qrs, qtd (dispersion), the axis of p wave were measured by ecg machine automatically. results: the p wave axis was significantly increased in patients with sle (49 ± 20 vs. 40 ± 18, p = 0.037) and the disease activity score was found positively correlated with p wave axis (r: 0.382, p = 0.011). the la volume and the peak systolic strain of the left atrium (la) were statistically different between the groups (p = 0.024 and p = 0.000). the parameters of the diastolic function; e/a and e/e’ were better in the control group than the patients with sle (1.1 ± 0.3 vs. 1.3 ± 0.3, p = 0.041 and 6.6 ± 2.8 vs. 5.4 ± 1.4, p = 0.036, respectively). conclusion: p wave axis was found significantly increased in patients with sle and positively correlated with selena-sledai score. as the risk score increases in patients with sle, p wave axis changes which may predict the risk of all-cause and cardiovascular mortality.