Background: Sleep deprivation (SD) is associated with worse cardiovascular outcome including mortality. Prolonged P-wave duration and P-wave dispersion (Pd) are known to represent inhomogeneous conduction of sinus impulses and are known to be electrophysiologic predictors of atrial fibrillation. Pd in normal subjects has been reported to be influenced by the autonomic tone. Because autonomic tone is affected by sleep and sleep duration, we evaluated the effect of acute SD on P-wave duration and Pd in healthy young adults and whether the effect was gender selective.
Methods: We obtained electrocardiograms of 37 healthy young volunteers (age: 28.45 +/- 7.97; 11 women) after a night of regular sleep and repeated after a night with sleep debt. We measured minimum and maximum P-wave durations (Pmin, Pmax) and Pd in milliseconds.
Results: Average sleep time of the subjects were 7.7 +/- 0.8 hours during regular sleep and 1.7 +/- 1.6 hours during a night of sleep debt (P < 0.001). Subjects had significantly lower values of Pmin in milliseconds after a night of sleep debt when compared to regular sleep (65.13 +/- 8.03 vs 74.86 +/- 10.95; P < 0.001), whereas they had significantly higher values of Pmax and Pd (102.16 +/- 9.46 vs 95.13 +/- 11.21; P < 0.001 and 37.02 +/- 8.11 vs 20.27 +/- 11.42; P < 0.001, respectively). In Pearson's correlation analysis Pmin was positively and Pmax and Pd were negatively correlated with sleep time (P < 0.001, r = 0.465; P = 0.003, r =-0.336 and P < 0.001, r =-0.698 respectively). Effect of SD on P-wave duration and Pd was similar for both men and women.
Conclusions: In conclusion, prolongation of Pmax and Pd in acute SD suggests that acute SD might contribute to development and/or recurrence of atrial fibrillation.