Coronary flow reserve

Coronary flow reserve (CFR) is the maximum increase in blood flow through the coronary arteries above the normal resting volume.^[1] Its measurement is often used in medicine to assist in the treatment of conditions affecting the coronary arteries and to determine the efficacy of treatments used.

Overview

When demand for oxygen in the myocardium is increased, the vascular resistance of the coronary arteries has the ability to reduce, and this can increase the volume of blood passing through the blood vessels. This reduction occurs because the arteries dilate, which causes an increase in the diameter of the lumen.^[2][3] The greatest potential for this change is normally in the branches (arterioles) of the coronary artery that penetrate the myocardium, rather than those on the surface of the heart. ^[1]

Measurement

Coronary flow reserve can be measured through a variety of methods, including digital subtraction cineangiography with coronary catheterization,^[4] doppler echocardiography,^[5] and positron emission tomography (PET).^[6]

Medical implications

Coronary flow reserve is used in diagnostics and treatment of patients suffering from conditions such as coronary artery disease and syndrome X.^[7] In the treatment of these conditions, vasodilators are used to allow sufficient blood to flow past a stenosis, for example, and the measurement of CFR enables the efficacy of such interventions to be measured. ^[3] In patients suffering from Anderson-Fabry disease, there is evidence to suggest that CFR can be reduced.^[5] When coronary flow reserve is used in medicine, it is often expressed with a numerical value, which is formed by dividing the maximal coronary blood flow by resting blood flow. This allows for an objective view, which can aid diagnosis and treatment.^[8]

See also

• Coronary circulation
• Vascular resistance
• Coronary artery

References

1. ^ ^{a b} [1] Julia Radó; Tamás Forster "The significance of coronary flow reserve in chest pain syndromes" (2001) Echo in Context
2. ^ Critical Stenosis Cardiovascular Physiology Retrieved 9th December 2009
3. ^ ^{a b} [2] D R Holdright; D C Lindsay; D Clarke; K Fox; P A Poole-Wilson; P Collins (1993) "Coronary flow reserve in patients with chest pain and normal coronary arteries" British Heart Journal
4. ^ [3] P. W. SERRUYS; F. ZIJLSTR; G. J. LAARMAN; H. H. C. REIBER; K. BEATT; JOS ROELANDT (1989) "A comparison of two methods to measure coronary flow reserve in the setting of coronary angioplasty: intracoronary blood flow velocity measurements with a Doppler catheter, and digital subtraction cineangiography" European Heart Journal
5. ^ ^{a b} [4] Paweł Petkow Dimitrow; Marek Krzanowski; Anetta Undas (2005) "Reduced coronary flow reserve in Anderson-Fabry disease measured by transthoracic Doppler echocardiography" Cardiovascular Ultrasound
6. ^ [5] Maurizio Galderisi; Arcangelo D'Errico (2008) "Beta-Blockers and Coronary Flow Reserve: The Importance of a Vasodilatory Action" Ingenta
7. ^ [6] Manfred Zehetgruber; Gerald Mundigler; Günter Christ; Deddo Mörtl; Peter Probst; Helmut Baumgartner; Gerald Maurer; Peter Siostrzonek (1994) "Estimation of coronary flow reserve by transesophageal coronary sinus Doppler measurements in patients with syndrome X and patients with significant left coronary artery disease" Journal of the American College of Cardiology
8. ^ [7] OM Hess; MJ McGillem; SF DeBoe; IM Pinto; KP Gallagher; GB Mancini (1990) "Determination of coronary flow reserve by parametric imaging" Circulation: American Heart Association