The instant wave-free ratio is a logical follow-on to FFR. Also a physiological assessment, iFR determines whether a stenosis is causing a limitation of flow in coronary arteries with subsequent ischemia. Like FFR, iFR is performed with high fidelity pressure wires that are passed distal to the coronary stenosis.
What is the difference between iFR and FFR?
Index definition. The FFR modality uses hyperemic agents to achieve a state of constant resistance. The iFR modality measures pressure during the wave-free period of the cardiac cycle when resistance is naturally constant.
What does iFR mean in cardiology?
The instantaneous wave-free ratio (iFR, sometimes referred to as the instant wave-free ratio or instant flow reserve) is a diagnostic tool used to assess whether a stenosis is causing a limitation of blood flow in coronary arteries with subsequent ischemia.
What does FFR?
Fractional flow reserve (FFR) utilizes a specialized guide wire to measure blood pressure within a coronary artery. … FFR is defined as the ratio of mean distal coronary pressure to mean aortic pressure.
What does iFR measure?
iFR measures the ratio of distal coronary pressure (Pd) to the aortic pressure (Pa) during an isolated period during diastole, called the “wave-free period.” During this “quiet” period, competing forces (waves) that affect coronary flow are inactive, creating a linear relationship between pressure and flow.
What is a normal iFR?
Therefore, when a stenosis is flow limiting, Pd and Pa pressures over the wave-free period diverge, with iFR values below 0.9 suggesting flow restriction (normal value is 1.0). Theoretically, iFR can be calculated using a single heartbeat, but is typically averaged over five beats for normalization.
What is a normal FFR?
An FFR of 1.0 is widely accepted as normal. An FFR lower than 0.75-0.80 is generally considered to be associated with myocardial ischemia (MI).
What is FFR in angiogram?
Fractional flow reserve (FFR) is a technique used in coronary catheterization to measure pressure differences across a coronary artery stenosis (narrowing, usually due to atherosclerosis) to determine the likelihood that the stenosis impedes oxygen delivery to the heart muscle (myocardial ischemia).
What is the CPT code for IFR?
In reviewing the procedure description, iFR allows for Fractional Flow Reserve (FFR) measurement that often does NOT require the step of administering a pharmacological stress agent. The code descriptors for the existing FFR codes (93571, 93572) specifically state that pharmacological induced stress is included.
What is FFR CT scan?
Fractional Flow Reserve – Computed Tomography (FFR-CT) is a noninvasive technology developed by HeartFlow Inc. to test for coronary artery disease. HeartFlow® technology uses computed tomography (CT) scans to calculate how much blood is flowing through the coronary arteries.
What is flow limiting stenosis?
A flow-limiting coronary stenosis was defined as a lesion with a diameter narrowing exceeding 50% (on CTA or on QCA) inducing a reversible perfusion defect in its subtending myocardial territory on MPI (myocardial ischaemia) (Figure 1).
What is Ivus used for?
Intravascular Ultrasound (IVUS) is a catheter-based diagnostic procedure used to view the inside of a coronary artery, providing a real-time view.
What is the root operation for the PTCA procedure of two coronary arteries?
Dilation: This root operation is most commonly used for percutaneous transluminal coronary angioplasty (PTCA). The stent placement for these procedures is identified by the device character.