Dr.S.Venkatesan MD

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