The ECG changes in ACS are “as dynamic as” the occluding thrombus.The initial events include sudden total occlusion, early lysis , trickle of flow, partial re-occlusion , reflow, no-flow etc. The extent of transmural vs sub-endocardial injury, the competing force of re-perfusing and necrotic wave front, would define ECG findings making the ST segment labile in early hours of ACS.This is also the basis of some cases of STEMI evolving into NSTEMI and vice versa.
A 65 year old man presented to with this ECG,
The initial diagnosis of NSTEMI was made , and hence thrombolysis was not considered. Even as the fellows were mulling over the diagnosis , we subsequently came to know there is one more ECG available taken few hours ago in another hospital .
It had something on it ,
The moment we saw this ECG it was decided to go ahead with thrombolysis .The final ECG after thrombolysis with (Streptokinase) showed further stabilization .The question of thrombolysis in NSTEMI though not indicated in general , in selected situations we need to Introspect !
How to mange a patient who presents as NSTEMI but had STEMI few hours ago ?
Four ways to ponder !
- This patient should not be lysed as we have to treat the current event not the past. ,(Its NSTEMI and no need for lysis) Just heparin,dual antiplatelets .That will do.
- One can go ahead with lysis as there is evidence for STEMI in prior ECG.
- There is ST elevation in AVr even in the second ECG and so you have to thrombolyse !
- “Come on guys , . . . are you still in the primitive era, of managing ACS in CCU , just forget the ECG take him to cath lab , suck out all thrombus and deploy a stent and come out”.
* The last one , though appear practical (and most of us would love to indulge ) is an unprofessional way of practicing cardiology.Management of ACS requires sound principles of ECG and its correlation with the Intra-coronary and myocardial pathology.
What happened to this patient ?
He did well, free of angina with minimal LV dysfunction. He was discharged .Will be reviewed two weeks later,for further evaluation.This is typical example of a patient with ACS managed without even entering cath lab.
ECG changes are as dynamic as the Intra-coronary blood flow in ACS. Various factors determine the ST elevation or depression.While ,thrombolysis is reserved for STEMI, NSTEMI has little or no benefits to accrue with thrombolysis .However this is applicable only for de-novo NSTEMI and may not apply for a STEMI in transition into NSTEMI as in the above patient .