Background: Whether non-invasive electrocardiographic parameters may be of similar relevance in pulmonary arterial hy­pertension (PAH) as in left ventricular heart failure (LVHF) remains unclear.

Aim: To examine a profile of electrocardiographic parameters in PAH and to determine their prognostic significance. Com­parison of profile in patients with pulmonary hypertension secondary to left ventricular dysfunction was planned in order to put PAH group results into context.

Methods: We included 41 patients with type 1.1/1.4.4 (according to the European Society of Cardiology) PAH and 31 patients with LVHF and type 2.1 pulmonary hypertension. All patients underwent 24-h ambulatory electrocardiography monitoring.

Results: Among heart rate variability parameters, only RMSSD was different (mean, 75 ms [PAH] vs. 112 ms [LVHF], p = 0.016). In PAH, fewer patients had ventricular tachycardia (15% vs. 48%, p = 0.004), abnormal deceleration capacity (54% vs. 84%, p = 0.011), positive heart rate turbulence (11% vs. 48%, p = 0.003), severe autonomic failure (10% vs. 39%, p = 0.005), and ventricular late potentials (LP) (19% vs. 62%, p = 0.001). In PAH, four deaths occurred in 42 months. In univariate analysis, the risk factors for death were: LP (hazard ratio 13.55, 95% confidence interval 1.41–130.72; p = 0.024), age, N-terminal prohormone of B-type natriuretic peptide, while the protective factors were minimal and mean heart rate, as well as the six-minute walk test (6MWT) distance. In multivariate analysis, the influence of LP and the 6MWT distance remained significant.

Conclusions: Ventricular LP were present in 19% of PAH patients and were the most powerful risk factor of mortality .