Am. J. Respir. Crit. Care Med.,
Volume 156, Number 6, December 1997, 2011-2014
Electrocardiographic Prediction of Hyperinflation
in Children
SANKARAN S.
KRISHNAN,
JULIAN
STEWART,
NIKHIL
AMIN,
RICHARD T.
GRIFFIN,
and
ALLEN J.
DOZOR
Department of Pediatrics, Division of Pulmonology and Cardiology, New York Medical College, Valhalla, New York
The mean frontal P wave axis in an electrocardiogram (ECG), which reflects the atrial orientation in
the thorax, is altered by the relationship between atria and the diaphragm and, therefore, by hyperinflation. To examine this relationship, 102 children (ages 6-18) with asthma were prospectively
studied. Lung volumes were estimated by plethysmography and a standard ECG obtained before and
after bronchodilator. The mean thoracic gas volume (TGV) was 120.7 ± 2.1% of predicted and the
mean P axis was 54.9 ± 1.5°. Sixty-two subjects (61%) had a "vertical" P axis (
60°). Of 27 subjects
with moderate or severe hyperinflation (TGV 130% predicted), 23 (85%) had a vertical P axis. As a
measure of significant hyperinflation, a vertical P axis had a sensitivity of 85%, specificity of 49%,
positive predictive value of 38% and a negative predictive value of 90%. After nebulized albuterol,
the mean TGV decreased to 96.4 ± 1.3% predicted and the mean P axis decreased by 7.1 ± 1.6°.
Sixty-two of 76 subjects (82%) with 15% decrease in TGV also had a decrease in P axis, and 62/67
subjects (93%) with a decrease in P axis also had 15% decrease in TGV. The sensitivity was 82%,
specificity 81%, and positive predictive value 93% for a decrease in P axis as a measure of decrease in
TGV. A vertical P axis combined with a decrease in P axis after bronchodilator is highly sensitive and
predictive for hyperinflation in children.
