Diurnal variation of the P-wave dispersion in chronic ischemic heart diseases

OBJECTIVEElectrocardiographic indices like maximum P-wave duration (Pmax) and P-wave dispersion (PD) can be used to detect patients with atrial conduction disorders, myocardial ischemia and those at risk for atrial fibrillation. Considering the diurnal variation of ischemia in patients with significant coronary lesions, this study was designed to investigate the diurnal variation of eventual atrial conduction abnormalities. METHODSForty-eight patients (31 male) with typical angina were grouped according to coronary angiography results as group 1 – 70% or more luminal reduction in at least one of the coronary arteries (n=28), and group 2 – normal coronary arteries (n=20). The difference between the Pmax and minimum P-wave durations (Pmin) is designated as PD. The diurnal Pmax, Pmin and PD values were compared between and within the groups. RESULTSThe morning Pmax value of group 1 was significantly higher than the value of group 2 (112±1 vs. 102±1 ms, P