From the Guidelines
Acute Coronary Syndrome (ACS) on EKG is typically diagnosed by looking for ST-segment elevation ≥1 mm in two or more contiguous leads, ST-segment depression, or T-wave inversions, and immediate management includes aspirin, anticoagulation, and consideration of dual antiplatelet therapy, with urgent reperfusion therapy needed for STEMI. When evaluating for ACS, other findings to consider include new left bundle branch block, hyperacute T waves, reciprocal ST depression, and pathological Q waves 1. The ECG is critical in diagnosing ACS, and a recording made during an episode of the presenting symptoms is particularly valuable, with transient ST-segment changes and T-wave inversions suggesting acute ischemia and a high likelihood of underlying severe CAD 1. For suspected ACS, the initial evaluation should be used to determine risk and to treat life-threatening events, with a provisional diagnosis of ACS, non-ACS cardiovascular condition, noncardiac condition with another specific disease, or noncardiac condition that is undefined 1. Key considerations in the management of ACS include:
- Aspirin (325 mg chewed) and anticoagulation with heparin or enoxaparin
- Dual antiplatelet therapy with clopidogrel (300-600 mg loading dose), ticagrelor (180 mg loading dose), or prasugrel (60 mg loading dose)
- Urgent reperfusion therapy for STEMI, either via primary PCI within 90 minutes or fibrinolytic therapy within 30 minutes if PCI is unavailable
- Beta-blockers (metoprolol 5 mg IV, up to three doses), nitroglycerin for chest pain (0.4 mg SL or IV drip), and morphine for pain relief. These EKG changes reflect underlying coronary artery occlusion causing myocardial ischemia, which if untreated can lead to irreversible myocardial damage, emphasizing the importance of rapid recognition and treatment 1.
From the Research
ACS on EKG
- Acute Coronary Syndrome (ACS) is a common diagnosis in preclinical emergency medicine, and its diagnosis can be facilitated by an EKG diagnosis within the first 10 minutes after medical contact 2.
- The EKG can help differentiate between ACS with and without ST segment elevations, which is crucial for determining the appropriate treatment approach 2.
- In patients with ACS, an EKG may show ST depression, ST elevation, T-wave inversion, or presence of Q waves, which can indicate the severity of the condition 3.
- Elevated troponin levels without ST-segment elevation on electrocardiography suggest non-ST-segment elevation ACS, which requires a different treatment approach than ST-segment elevation myocardial infarction (STEMI) 3.
Treatment Approaches
- Patients with ACS should receive coronary angiography with percutaneous or surgical revascularization, as well as initiation of dual antiplatelet therapy and parenteral anticoagulation 3.
- The use of P2Y12 inhibitors, such as clopidogrel, ticagrelor, and prasugrel, has been shown to be effective in reducing major adverse cardiovascular events (MACE) in patients with STEMI undergoing percutaneous coronary intervention (PCI) 4, 5.
- Ticagrelor and prasugrel have been associated with lower risks of MACE after STEMI than clopidogrel, and ticagrelor has been associated with a marginal reduction compared with prasugrel 5.
Importance of EKG in ACS Diagnosis
- The EKG is a crucial diagnostic tool in the diagnosis of ACS, and its use can help identify patients who require immediate medical attention 2, 3.
- The EKG can help identify patients with STEMI, who require prompt reperfusion therapy, as well as those with non-ST-segment elevation ACS, who may require a different treatment approach 2, 3.