ECG IN ACS WITH ST SEGMENT ELEVATION ~ clinical and electrical challenge ~
The electrocardiographic (ECG) diagnosis of ST-segment elevation acute coronary syndrome (ACS) represents a challenge to all health care providers, especially those working in emergency units/departments, a key-test for early diagnostic in acute coronary syndrome (ACS), as well as in chronic ischemia. It must be done as soon as possible from the first medical contact with the patient (usually, in the first 10’), keeping in mind that early identification of ST-segment elevation (STE) acute myocardial infarction (AMI) greatly reduces the time to reperfusion therapy with markedly lower morbidity and mortality rates, including both lower 30-day and 5-year mortality rates. The reduction in time to therapy, regardless of the reperfusion treatment used, is in large part due to prehospital identification of STEMI and prearrival notification of the event. Early detection and treatment of a STEMI has the potential to limit the myocardial damage and acute cardiovascular complications, reduce mortality and improve the quality of life.
Early ECG correct diagnostic allows us to identify the patients who will benefit from primary angioplasty or thrombolysis.
The abnormal patterns of the ECG vary considerable and they depend upon:
- duration of the ischemia (acute, evolving/chronic),
- extension of the ischemia (transmural/not),
- topography (anterior, postero-inferior, right ventricle, etc.)
- the presence of other abnormalities - BBB, WPW, pacemaker, etc.
The ECG pattern provides us, also, prognostic data - the risk of death and non-fatal myocardial ischemia on short term in patients with ACS.
If ECG abnormalities are associated with a typical clinical aspect, a new wall motion alteration (seen in echocardiography), synergic as localization, the probability of AMI is increased considerably.
Any suspicious ECG findings should be matched against patient presentation and physical exam, history and risk factors, biological markers, old ECG’s (extremely valuable if available) and serial ECG’s (for dynamic changes in time).