1. Saša Nježić, Medicinski fakultet Banja Luka ::Save Mrkalja 14,
Republic of Srpska, Bosnia and Herzegovina
2. Nenad Filipović, Univerzitet u Kragujevcu (FIN, PMF, FMN), Serbia
3. Fatima Živić, Fakultet inženjerskih nauka Univerziteta u Kragujevcu, Serbia
4. Dragoljub Mirjanić, Akademija nauka i umjetnosti Republike Srpske, Bana Lazarevića 1, Banja Luka, Republic of Srpska, Bosnia and Herzegovina
The derivation of FFR from the Poiseuille`s equation and the relationship between FFR and the degree of stenosis is shown. Fractional flow reserve (FFR) is the “gold standard” for assessing the physiological significance of coronary artery disease during invasive coronary angiography. Blood flow through blood vessels can be expressed by the Poiseuille`s equation and using Poiseuille's law to calculate the narrowed vessel's hemodynamic resistance. The myocardial fractional flow reserve (FFR) is clinically used as a stenosis-specific index. The relation between the FFR and the degree of stenosis (defined as the fractional cross sectional area narrowing) was investigated, including the influence of the aortic and venous pressures and the capillary resistance. Studies have shown that the fractional flow reserve has a high correlation with non-invasive indicators of myocardial ischemia during exercise testing, such as dobutamine stress echocardiogram, stress echocardiography and scintigraphy, as well as combination of these methods.