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How do you explain this ? 99% occlusion still TIMI 3 flow ?

Answer

A. It could be a parallax error. Lesion may not be tight. Should be seen in other views.

B . Forcible Injection by the operator, make it an artificial TIMI -3 flow.

C .Such flows are very much possible .It Indicates a healthy distal micro-circulation a vascular bed in a fully dilated mode.

D. TIMI flow is not reliable here . We need TIMI frame count to confirm.

Follow up questions

1.How much will be the FFR ?

Likely to be less than . 8 definitely , but surprises can happpen

2.Can he be asymptomatic ?

Unlikely.

Final message

Coronary occlusions are ominpresent . While we have mastered the art of successfully taming these anatomical enemies , we are still very much ignorant what these lesions actually do, to the physiology, inspite of half a dozen flow reserve Indices we have.(FFR,iFR, rFR,qFR, dP/dT ,etc)

The question is, at what level of obstruction, it really limits the coronary bllod flow significantly ( both at rest and exertion) . One thing is clear , it is higly variable & Individualistic, the secrets of which lies deep, in the domain of invisible micro-vascular network integrity.

Counterpoint

TIMI flows may no longer be valid in non-ACS situations. The name TIMI , by itself carries flow after thrombolysis. For some unexplained (& debatable ) reasons, we are used to apply this flow grade , in every angiographic flow scenerios irrespective of underlying clinical entity.

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While anatomical  grading of obstructive  coronary lesions are  quiet easy ,functionalc assessment is always difficult.The famous TIMI grading system had one unique problem .TIMI 1 and 2 grades are relatively easy to grade. TIMI 3 flow  which corresponds to normal penetration  and normal  distal perfusion  . This distal perfusion was entirely optical .

This was an important issue , in assessing post  PCI or thromolysis patients . It was realised much later , TIMI 3 flow is  stunningly  heterogenous group  .It was  ironical  ,  even after a successful PCI ,  restoration of TMI3 flow  could not be relied upon as an index of successful PCI  .

So , the PAMI study group included time as additional factor in grading TIMI 3 flow. PAMI 3 is  essentailly same as  TIMI 3  flow but  with a  condition , complete  distal vessel filling  must  occur within 3 cardiac cycle . PAMI 3 can be termed as a   refined version of TIMI 3 introduced in the evaluation of success of primary PCI . This helps us  define  or  diagnose   slow filling .

What are the other ways  to grade TIMI 3 flow

  • Myocardial blush index
  • TIMI frame count ( < 25 frames )

PAMI : Primary angioplasty in myocardial infarction

TIMI :  thromolysis in acute myocardial infarction

Reference:

http://circ.ahajournals.org/cgi/content/full/circulationaha;104/6/624

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