Effect of balloon-induced acute ischaemia on P wave dispersion during percutaneous transluminal coronary angioplasty.

AIMS: P wave dispersion is a recent ECG marker that reflects discontinuous and inhomogeneous conduction of sinus impulses, which has been studied in a limited number of cardiac conditions. The aim of our study was to investigate the effects of angioplasty induced-ischaemia on atrial conduction abnormalities as estimated by P maximum and P dispersion.

METHODS AND RESULTS: The study consisted of 67 consecutive patients (41 men, mean age 58 +/- 11 years) with 1-vessel coronary artery disease who underwent elective single vessel coronary angioplasty (left anterior descending (LAD) coronary artery in 28 patients, the right coronary artery (RCA) in 22 patients and the left circumflex coronary artery (LCx) in 17 patients. All patients underwent 12-lead surface ECG before the first inflation (baseline) and then 60 s after intra-coronary balloon inflation. The maximum P wave duration, the minimum P wave duration, and P wave dispersion (Pd=Pmax - Pmin) were calculated from 12-lead surface ECGs. Baseline P wave duration measurements were not significantly different among the patients with LAD, RCA and LCx coronary artery disease (P>0.05). P dispersion and P maximum were significantly higher during balloon occlusion compared with the baseline condition in all three types of coronary dilatation procedures. However, P minimum was not found to differ between baseline and during balloon occlusion (P>0.05).

CONCLUSION: The prolongation of P wave dispersion may be a useful and simple additional marker for myocardial ischaemia.