Effect of CABG on P-wave Dispersion and the Relationship between AF and P-wave Dispersion

Background: Atrial fibrillation (AF) is a common complication after CABG. It is associated with doubling of
mortality rate and increased incidence of CHF, MI, renal insufficiency, and stroke which prolongs hospital stay
and is associated with increased rate of re-hospitalization.
In this study we examined the effect of CABG on atrial electrophysiology as reflected by P-wave dispersion.
Patients and Methods: A total of 197 consecutive patients undergoing elective CABG due to CAD were monitored
for 4 days in hospital and their daily ECGs were obtained. .Differences in P-wave dispersions were compared
between the patients who developed AF and those maintaining sinus rhythms.
Results: Post-operative AF occurred in 18.2% of patients, who showed statistically significant increase of P
wave duration, in lead aVL of pre-op ECG (79.4±25.0 vs 70.1±22.4; P = 0.032). In addition, P wave dispersion
was significantly increased on first and third days of post-op period (77.2±22.0 vs 67.5±22.2; P=0.018) and
(69.4±22.7 vs 61.1±20.3; P= 0.035) respectively, in those developing AF rhythm compared to patients remaining
in sinus rhythm .
Conclusion: Our result indicates that P-wave dispersion is a risk factor for development of AF in patients undergoing
CABG.