Pressure-derived measurement of coronary flow reserve
Philip MacCarthy, BSc, PhD, MRCP*, ,*,
Alexandre Berger, MD*,
Ganesh Manoharan, MD, MRCPI*,
Jozef Bartunek, MD, PhD*,
Emanuele Barbato, MD*,
William Wijns, MD, PhD*,
Guy R. Heyndrickx, MD, PhD*,
Nico H.J. Pijls, MD, PhD and
Bernard De Bruyne, MD, PhD*
* Cardiovascular Center, OLV Clinic, Aalst, Belgium
Department of Cardiology, King's College Hospital, London, United Kingdom
Catharina Hospital, Eindhoven, the Netherlands
View larger version (18K):
[in a new window]
|
Figure 1 (a) Scatter plot of coronary flow reserve (CFR) values derived by thermodilution (CFR thermo) and from pressure measurements alone (CFR pressure) in hemodynamically significant atherosclerotic lesions in human coronary arteries (protocol 1). (b) Bland-Altman plot showing the relationship of the difference between pressure-derived and thermodilution-derived CFR and the mean of the two values.
|
|
View larger version (18K):
[in a new window]
|
Figure 2 (a) Scatter plot of all pooled coronary flow reserve (CFR) values derived by thermodilution (CFR thermo) and those values from pressure measurements alone (CFR pressure) in artificial stenoses created by balloons inflated within six stented human coronary arteries (protocol 2). (b) Bland-Altman plot showing the relationship of the difference between pressure-derived and thermodilution-derived CFR and the mean of the two values.
|
|
View larger version (108K):
[in a new window]
|
Figure 3 This figure shows illustrative examples of two types of stenosis with respective hyperemic pressure traces. These examples were not cases from the primary data set but are chosen to illustrate this concept. In the case of stenosis A, a discrete stenosis in a right coronary artery (RCA), friction is less important, the resting pressure gradient is low but increases markedly on induction of hyperemia as the quadratic relationship of the fluid dynamic equation is dominant. Pressure-derived coronary flow reserve (CFR) is overestimated in this situation. With the longer, more diffuse but less severe stenosis B, the resting pressure gradient is greater, but the increase on induction of hyperemia is less, as the linear component of the fluid dynamic equation (f) is more important. In this latter stenosis, pressure-derived CFR is underestimated. FFR = fractional flow reserve; Pa = aortic pressure; Pd = distal coronary pressure.
|
|
|
