Instantaneous Wave-Free Ratio: Definition, Uses, and Clinical Overview
Instantaneous Wave-Free Ratio is a way to measure how much a coronary artery narrowing is limiting blood flow. It is calculated during a heart catheterization using a thin pressure-sensing wire. It compares pressure before and after a narrowing during a specific part of the heartbeat. It is commonly used to help decide whether a coronary blockage is likely to benefit from stenting or other treatment.