AJP - Heart and Circulatory Physiology, Vol 242, Issue 4 507-H511, Copyright © 1982 by American Physiological Society
New method for measuring QRS duration using high-frequency electrocardiography
V. Bhargava and A. L. Goldberger
Definition of QRS onset and offset is a basic problem in
electrocardiography. Current techniques rely either on subjective estimates
or on computer algorithms using QRS derivative or spatial vector velocity
parameters. We developed a spectral method based on the observation that
the QRS complex, unlike the P wave, PR segment, or ST-T complex is
comprised of significant frequencies greater than 50 Hz. Accordingly, we
adapted a microprocessor-based electrocardiograph (ECG) system with a
signal-averaging program to reduce noise and a 50-300 Hz digital filter.
Leads I and aVF were simultaneously acquired by computer in 40 subjects
with a wide range of QRS duration (55.5-161 ms). Excellent correlation (r =
0.98) was noted between high-frequency QRS duration measurement and careful
visual determinations made at high gain and expanded time scale. The
high-frequency ECG appears to provide an objective physiological definition
of the QRS complex based on spectral content not on morphology or slope.
