Prevalence of interatrial block in healthy school-aged children: definition by P-wave duration or morphological analysis.
BACKGROUND
P waves > or = 110 ms in adults and > or = 90 ms in children are considered abnormal, signifying interatrial block, particularly in the first case.


METHODS
To evaluate the prevalence of interatrial block in healthy school-aged children, we obtained 12-lead digital ECGs (Cardioperfect 1.1, CardioControl NV, Delft, The Netherlands) of 664 healthy children (349 males/315 females, age range 6-14 years old). P-wave analysis indices [mean, maximum and minimum (in the 12 leads) P-wave duration, P-wave dispersion, P-wave morphology in the derived orthogonal (X, Y, Z) leads, as well the amplitude of the maximum spatial P-wave vector] were calculated in all study participants.


RESULTS
P-wave descriptor values were: mean P-wave duration 84.9 + or - 9.5 ms, maximum P-wave duration 99.0 + or - 9.8 ms, P dispersion 32.2 + or - 12.5 ms, spatial P amplitude 182.7 + or - 69.0 microV. P-wave morphology distribution in the orthogonal leads were: Type I 478 (72.0%), Type II 178 (26.8%), Type III 1 (0.2%), indeterminate 7 (1%). Maximum P-wave duration was positively correlated to age (P < 0.001) and did not differ between sexes (P = 0.339). Using the 90-ms value as cutoff for P-wave duration, 502 (75.6%) children would be classified as having maximum P-wave duration above reference range. The 95th and the 99th percentiles were in the overall population 117 ms and 125 ms, respectively. P-wave morphology type was not in any way correlated to P-wave duration (P = 0.715).


CONCLUSIONS
Abnormal P-wave morphology signifying the presence of interatrial block is very rare in a healthy pediatric population, while widened P waves are quite common, although currently classified as abnormal.
1st University Department of Cardiology, Hippokration Hospital, 22, Miltiadou Str., 15561, Athens, Greece. hrodil1@yahoo.com
Polychronis
P
Dilaveris
Leonidas
L
Raftopoulos
Georgios
G
Giannopoulos
Stylianos
S
Katinakis
Dimitrios
D
Maragiannis
Dimitrios
D
Roussos
Konstantinos
K
Gatzoulis
Andreas
A
Michaelides
Christodoulos
C
Stefanadis
D000293:Adolescent; D054537:Atrioventricular Block / Q000453:epidemiology*; D002648:Child; D004562:Electrocardiography / Q000379:methods* / Q000706:statistics & numerical data*; D005260:Female; D006115:Greece / Q000453:epidemiology; D006801:Humans; D008297:Male; D015995:Prevalence; D012016:Reference Values; D012815:Signal Processing, Computer-Assisted; D014672:Vectorcardiography / Q000379:methods / Q000706:statistics & numerical data