Effect of isolated coronary artery ectasia on dispersion of P-wave and QT interval

Coronary artery ectasia (CAE) is well-recognized, angiographic finding of abnormal coronary artery dilatation, and detected in 0.3–5.3% of angiographic studies. The gold standard for diagnosis this type of aneurysm is coronary angiography, which provides information about the size, sample, location and number of aneurysms. Despite growing prevalence in recent years, controversy still exists as to the pathogenetic mechanisms that underlie this entity. In this study we search the effect of isolated CAE on P-wave and QT interval dispersion. Twenty patients (mean age: 60 ± 9.7 years) with isolated CAE (group I) were included in the study and 18 control subjects (group II) matched in sex and age. Both groups underwent a standard 12-lead surface electrocardiogram recorded at 50 mm/s. Maximal (P max) and minimal P-wave durations (P min) are measured. P dispersion (PD) was defined as the difference between P max and P min. QT interval was measured from the onset of the QRS complex to the end of the T-wave, defined as the return to the T–P isoelectric line. The mean of three consecutive intervals in each analyzable lead was taken for analysis. QT dispersion was defined as the difference between the longest and shortest QT intervals and the rate corrected with Bazett’s formula. P max (117.1 ± 4.6) and PD (34.2 ± 5.4) were significantly higher in ectatic patients (group I) than those of the control (group II) [P max (100.5 ± 5) and PD (18 ± 5.4)], while no significant difference between the two groups as regards P min. C QT duration (401 ± 4.4), QT dispersion (31.7 ± 3), and C QT dispersion (33.9 ± 3.3) were significantly higher in group I than those of group II [C QT duration (391.9 ± 2), QT dispersion (27.3 ± 1), and C QT dispersion (29 ± 0.9)]. While there were no statistically significant difference between the two groups as regards echo data (EDD, ESD, EF, LA, LVMI, and AO). Isolated CAE were found to be associated with prolonged dispersion of P-wave and QT interval.