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Posts Tagged ‘silent Ischemia vs angina’

Now , some one wanted to know,  Can we diagnose unstable angina without Chest pain ?

Crazy question isn’t , Angina by definition  should have chest pain .There is nothing called silent angina , only silent Ischemia  .

  • We know Ischemia can occur silently .
  • We also know STEMI can occur silently (About 10 % of MI do occur without any symptoms )
  • If STEMI occurs  silently  why not UA/ NSTEMI combo ? (Collectively called as  NSTE-ACS)

The debate goes like this .If stable angina can present with equivalents ? what prevents  “Unstable angina”  to present with  Anginal  equivalents without chest pain ?

If  a diabetic patient who had a silent MI in the past  . . .  subsequently  experience  severe episodes of resting ischemia  , will he feel the pain , that is supposed to occur  with his  “unstable angina”  or not ?

Hmm , difficult to guess right,   So it seems highly plausible  UA/NSTEMI  do  occur silently ! Literature hasn’t looked into this specifically. Chest pain is built integral  into definition of UA , infact it is a symptom  complex rather than an disease entity by itself, while NSTEMI is ECG and enzyme combo ! Making the term  NSTE-ACS  look  perfect.

Any other technical explanation ?

The concept of Ischemic cascade says angina occurs last, well after biochemistry , wall motion defect and ECG , hence its distinctly possible for UA/NSTEMI present to be painless !

Final message

Anginal pain perception is related to intactness of neurogenic circuits and also probably the severity of Ischemia.If full thickness myocardial necrosis can be painless in few, nothing prevents from an episode of UA/NSTEMI  be truely painless .

Clinical implication of this conundrum

Can we admit a patient as UA/NSTEMI with out chest pain ?

Yes, it would seem so .

No, we can’t .

Indeed we can , if ECG changes are there .

No, we can admit even with normal ECG if its real unstable angina.

This is the crux of the problem in ERs all over the globe. Our knowledge base is simply not good enough. Every one of us has seen Troponin positive silent NSTEMIs ! but . . . to me still something is missing in the link .

Modern day approach 

Pain or no pain,any  fresh ECG changes ( Both T and ST shifts*) should be rushed to cath lab.Whenever you are not sure .Always better to err on the side of over investigation.That’s the mantra ! So ,you do an Angiogram , find an Incidental intermediatroy lesion which may not be responsible for the ECG changes but you are compelled to go after it FFR//iFR , OCT, IVUS and so on !

*There is huge list of non Ischemic ST/T shifts in ECG that can be read elsewhere .

Counterpoint

Can’t agree with this article. Foolish to diagnose UA without chest pain. Never  treat ECG  in isolation unless its a convincing  ST elevation or depression with clinical input and thorough scrutiny of  past record . Realise , how important is  the basics principles of medicine taught  by Oslers and Cushings a  century ago.

 

 

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