What is an electrocardiogram (EKG)?

From the Guidelines

An electrocardiogram (EKG or ECG) is a crucial non-invasive test that records the electrical activity of the heart, providing valuable information for diagnosing and managing heart conditions, particularly arrhythmias, heart attacks, and structural abnormalities. The test is commonly performed during routine physical exams, especially for patients with heart disease risk factors, symptoms like chest pain or palpitations, or when monitoring the effects of heart medications 1.

Key Points About EKG

• A standard 12-lead EKG provides multiple views of the heart's electrical activity from different angles, allowing for comprehensive assessment 1.
• The test typically takes only a few minutes and is painless, with results appearing as wave patterns on paper or a digital screen, showing the timing and strength of electrical signals as they move through different parts of the heart 1.
• Healthcare providers analyze these patterns to identify abnormalities in heart rate, rhythm, and structure, which is essential for the diagnosis of cardiac arrhythmias and acute myocardial ischemic syndromes 1.
• EKGs are appropriately used as a screening test in many circumstances, including before and after certain medical procedures, and for patients on medications that may affect the heart 1.

Clinical Applications

• EKG is used to assess patients with suspected cardiac disease, including those with symptoms like chest pain, shortness of breath, or palpitations 1.
• It is also used to monitor patients with known heart conditions, such as heart failure, coronary artery disease, or arrhythmias, and to assess the effectiveness of treatments 1.
• In patients with acute coronary syndromes, EKG is crucial for diagnosing myocardial infarction and guiding management decisions, including the need for reperfusion therapy 1.

Importance of EKG in Clinical Practice

• Electrocardiography is the most commonly used diagnostic test in cardiology, contributing significantly to the diagnosis and management of patients with cardiac disorders 1.
• Proper interpretation of EKG results is essential for identifying cardiac arrhythmias and acute myocardial ischemic syndromes, which account for the majority of cardiac catastrophes 1.

From the Research

Ekg and Cardiac Troponin

• Cardiac troponin is widely used for the diagnosis of acute myocardial infarction 2
• Elevated troponin levels have been found to play a prognostic role in ischemic stroke and are associated with atrial fibrillation 2, 3
• The use of biomarkers, including troponin, in the management of atrial fibrillation is not routinely recommended by current guidelines, but there is growing evidence of its potential role 3

Troponin and Atrial Fibrillation

• Higher levels of cardiac-specific troponin may be associated with the risk of incident and recurrent atrial fibrillation and its complications 3
• Troponin elevation can be used as a prognosticator in patients with atrial fibrillation and for risk stratification to predict which patients are more prone to stroke or other thromboembolic events 2

Cardioversion and Troponin

• External transthoracic direct current cardioversion did not result in myocardial injury within the first 6 hours as measured by high-sensitivity troponin T in one study 4
• However, another study found that cardioversion can lead to mild but significant troponin I rise as measured with a high-sensitivity assay, particularly in patients with relatively large left ventricular end-diastolic dimension 5

Diagnosis and Risk Stratification

• The diagnosis and risk stratification of chest pain patients in the emergency department, including those with acute coronary syndromes, may involve the use of troponin and other biomarkers 6