Indication for thrombolysis in ST elevation MI is mainly determined by clinical and ECG features. ST elevation of more than 1mm in two consecutive leads with a clinical suspicion of acute coronary event demands immediate thrombolysis.
Early repolarisation syndrome(ERS) is a is typical mimicker of STEMI . In ERS , ST segment elevation occurs in many leads especially precardial .This entity is estimated to occur in nearly 3-5% of population where a genetic variation in the potassium channel activation is reported.
If they land in ER with some sort of chest pain , chances are high for labelling them as ACS . It is not uncommon for CCU physicians to witness an ERS being lysed . Even in many of the land mark trials (ISIS ) there has been many inappropriate thrombolysis , recognised later on.
What can really happen if you thromolyse them inadvertently ?
Generally nothing happens . But they are exposed to the risk of thromolysis. The ECG changes persist. And troponin will be negative and echocardiogram will not reveal any wall motion defect.
Are we legally liable if a patient with ERS was thrombolysed and he ends up with a bleeding complication like stroke ?
While the physician may feel guilty , there is no reasons for him to feel so.The guidelines are kept little lineant for the indication for thromolysis. When we are promoting a strategy of early thrombolyis on a population based approach in STEMI , there is bound to have a overlap with normality .The benefits out of early thrombolysis for eligible patients for outweigh the few inappropriate thromolysis.
When you want to catch a real criminal it is unavoidable, one gets hold of all suspected criminals before letting them free . Unfortunately in this exercise , some of the innocent might experience intimidation or even a injury at the hands of law enforcers.
Similarly if a patient with ERS develop a severe esophageal spasm and typical angina like chest pain he is absolutely certain to receive thrombolysis. (Troponin, CPK come later , and the results never veto the clinical and ECG criteria ,except probably in LBBB) .Many times critical time dependent decisions are prone for errors in CCU. So it may be unscientific to ask why an ERS was thrombolysed !
How can one prevent inadvertent thrombolysis in ERS ?
Always ask for the previously recorded ECGs .If it is available and look exactly similar to the current ECG chances are unlikely for ACS. In ERS ST segment is generally concavity upwards . ACC/AHA guideline for STEMI ,is aware of this fact , but still advices thrombolysis for all ST elevation irrespective of the morphology of ST segment elevation. This is propably intentional, not to incorporate morphology cirteria of ST elevation for thromolysis .It would potentially make many true STEMIs diagnosed falsely as ERS and deny thrombolysis.
What is the latest news about ERS ?
Now data are coming up, ERS is not entirely benign condition.Some of them ( Even a fraction of ERS population could be a significant number) can have a overlap between Brugada syndrome and they could be prone for dangerous ventricular arrhythmia when challanged with ischemic or other stress.
Dr.S.Venkatesan MD 