K. Hamaoka et al., CORONARY ARTERIAL FLOW-VELOCITY DYNAMICS IN CHILDREN WITH ANGIOGRAPHICALLY NORMAL CORONARY-ARTERIES, Circulation, 92(9), 1995, pp. 2457-2462
Background There have been few reports about coronary hemodynamics in
children during the process of growth. In the present study, to assess
the characteristics of coronary flow dynamics in children, we examine
d the phasic coronary flow-velocity (CFV) patterns at rest and during
peak hyperemic responses in children with angiographically normal coro
nary arteries. Methods and Results Spectral Doppler phasic coronary fl
ow velocity was recorded with a 0.018-in intracoronary Doppler guidewi
re at rest and during peak responses after intracoronary bolus injecti
on of ATP in 30 patients with Kawasaki's disease (age, 8.2+/-5.1 years
; 24 boys and 6 girls) without angiographic coronary lesions. Average
peak velocity (APV), maximum peak velocity (MPV), and diastolic-to-sys
tolic velocity ratio (DSVR) were evaluated in the left anterior descen
ding coronary artery (LAD), left circumflex artery (LCx), and right co
ronary artery (RCA). Coronary vasodilator reserve (coronary flow reser
ve [CFR]) was calculated as the ratio of ATP-induced hyperemic to base
line APV. Flow-velocity parameters in RCA were significantly lower tha
n those in the LAD and LCx in both proximal and distal portions. Altho
ugh the distal LCx had significantly lower values of APV and MPV than
did the proximal LCx, there was no significant difference between the
and MPV. All three coronary vessels showed a diastolic dominant flow p
attern in each segment. This coronary flow pattern was less marked in
the RCA than in the LCA. All three coronary vessels showed a significa
nt increase in APV and a significant decrease in DSVR after ATP admini
stration. CFR was significantly lower in the LCx than in the LAD or RC
A (P<.01: 1.93+/-0.34 in LCx versus 2.32+/-0.42 in LAD and 2.37+/-0.44
in RCA). From the view of aging, it was revealed that APV values in t
hree vessels were higher in the younger group than in the older group.
CFR values in the LAD and LCx were significantly lower in the younger
group than in the older group (P<.001 in LAD: 2.0+/-0.28 in the young
er versus 2.53+/-0.37 in the older; P<.01 in LCx: 1.61+/-0.15 in the y
ounger versus 2.06+/-0.31 in the older). In addition, intracoronary in
jection of ATP did not increase the absolute angiographic coronary lum
inal diameter. Conclusions With the use of an intracoronary Doppler gu
idewire, we demonstrated that there are some characteristic findings i
n CFV dynamics in childhood. These physiological characteristics in CF
V dynamics that occur with aging and occur in each vessel must be take
n into consideration in the study of the coronary circulation in child
ren.