TIMI grade 0 perfusion is defined as which?

• A. No perfusion
• B. Minimal perfusion
• C. Partial perfusion
• D. Complete perfusion

Answer: (A)

TIMI flow grading describes how well contrast reaches the distal coronary bed on angiography. TIMI grade 0 means there is no perfusion beyond the blockage—the contrast does not reach the distal vessels and there is no antegrade flow past the occlusion. In other words, no distal opacification occurs. Higher grades reflect increasing levels of perfusion: minimal perfusion (tiny amount of contrast beyond the occlusion), partial perfusion (distal bed fills but not completely), and complete perfusion (normal distal filling). A grade 0 finding indicates total occlusion with no forward flow and often signals the need for urgent reperfusion.