The Journal of Thoracic and Cardiovascular Surgery, Vol 72, 62-66, Copyright © 1976 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
Delayed timing of heart and arterial sounds in patients with implanted pacemakers
M Hasegawa and S Rodbard
We have recorded the timing of the heart sounds and the arterial sounds
with reference to the onset of each cardiac cycle in 16 patients before and
after implantation of a pacemaker prosthesis, and in an additional 18
patients after pacemaker implantation only. The interval between the QRS
complex and the Korotkoff sound at diastolic pressure (QKd) is markedly
prolonged, from 206 to 294 msec., a change corresponding to 10 standard
errors of the mean difference. Likewise, the Q-Korotkoff interval at
systolic pressure (QKs) is prolonged from 329 to 414 msec. The interval
between the QRS complex and the onset of the first sound (S1) is prolonged
by approximately 90 msec., whereas the interval between the QRS and the
second heart sound (S2) is prolonged by 70 msec. We noted an associated
increase in heart rate, a slight decrease in systolic pressure, an increase
in diastolic pressure, a decrease in pulse pressure, and a slight decrease
in the deltaP/deltat at the brachial artery measured indirectly and
noninvasively.