Electrocardiographic P-wave characteristics in patients with end-stage renal disease: P-index and interatrial block

P-wave parameters including P-wave dispersion (P d) have been examined in general population to predict development of atrial fibrillation (AF). But data on end-stage renal disease (ESRD) population are limited. P index (Pi) and interatrial block (IAB) as novel parameters may more accurately predict AF and have not been previously investigated in ESRD patients. We aimed to evaluate these novel ECG parameters in ESRD patients.

Eighty-six HD, 47 CAPD, and 43 age- and gender-matched control subjects were enrolled in the study. P-wave duration was measured in all 12-leads of the surface ECG. The standard deviation of the P-wave duration across the 12 ECG leads was accepted as a Pi. P-wave duration above and equal to 110 ms was defined as IAB. All P-wave parameters were evaluated digitally by two observers.

Pi was found to be significantly different among the groups in ANOVA. In post hoc analysis, P i was increased in HD group compared with the control group (p = 0.01). Also, P i tended to increase in CAPD group compared with controls (p = 0.06). The effect of ESRD on P i was independent of age, gender, and systolic blood pressure in univariate covariant analysis. The prevalence of IAB was 61, 55, and 32 % in patients with HD, CAPD, and controls, respectively (p = 0.001). P d was significantly higher in HD group compared with healthy controls. However, Pd values of CAPD patients did not show significant difference compared with controls.

The present study demonstrated that IAB frequency and Pi were increased in patients with ESRD.