Dr.S.Venkatesan MD

Those who answered  “Yes” ,  can leave this article . Those who answered  “No” read further .

* Logic would tell us myocardial revascularisation should correct  stress induced ischemia and it  should disappear promptly  . This does not happen in all cases  real world  ! That is  why medicine is  different  from mathematical science .

Some of the  reasons for  persistence of stress positivity even after an apparently successful PCI are  . . .

1. Incomplete  correction of ischemia. (Ideally  to be referred as failed PCI )
2. Error in Identifying culprit 9Angina related artery ) .Common feature of poorly worked up  multivessel CAD.
3. Re-stenosis /Re-occlusion
4. Doing very early stress test without giving time for revascularisation to work *
5. Rapid progression of non culprit lesions .(Sub -optimal medical management )
6. Chronic N0-Reflow phenomenon  surrounding  area of infarct .(Especially in  PCI of CTOs)
7. Dyskinetic  or grossly remodeled ventricular segments  can result in non ischemic positive EST response (ST drag **)
8. Associated systemic conditions especially  Anemia/ SHT & LVH -(False positive )
9. Many diabetic patients may  continue to show stress ischemia due to  small vessel disease.
10. A  patient with  syndrome X  characters  can have incidental  epicardial lesion as well . In such a patient EST will always be positive .

* Optimal time to do  EST  for assessing the  efficacy of  PCI/CABG is not established .Six months may be the reasonable point .If done within 2- 3 months it may  end  up  in embarrassment for the Interventionist . (So only it is kept at 6 months , this also help us  greatly  as  we can always blame it on poor life style control and progression of  the disease !)

** No reference  for this  , a  personal observation .We know  Q leads following MI ,  will show ST elevation during stress test especially if the segments are dyskinetic  . In leads diagonally opposite to q leads ,  ST depression is observed . This may not be  a evidence for true  ischemia . It probably represents   ST drag due to mechanical stretch .