What does a 12-lead ECG examine?
Disease description:
I have recently been experiencing palpitations and shortness of breath, so my doctor performed a 12-lead ECG test. What does a 12-lead ECG check?
Doctor's answer (1)
Dr. Tian Hongbo
A 12-lead electrocardiogram (ECG) is an important diagnostic tool used to evaluate the electrical activity of the heart. By recording the heart's electrical activity from different angles, it helps physicians assess cardiac health. The 12 leads include four limb leads (I, II, III, aVF), three augmented unipolar limb leads (aVR, aVL, aVF), and five precordial leads (V1 to V6). The main aspects evaluated are:
1. Myocardial ischemia: Assessing the presence of myocardial ischemia through ST segments and T waves on the ECG, helping to identify acute myocardial infarction or prior myocardial infarction.
2. Cardiac rhythm: Identifying arrhythmias such as atrial premature contractions, ventricular premature contractions, and paroxysmal supraventricular tachycardia.
3. Electrolyte imbalances: Conditions such as hyperkalemia or hypokalemia can be recognized through specific ECG changes.
4. Arrhythmias: Including tachycardia, bradycardia, and premature beats.
5. Drug effects: Certain medications can cause ECG changes; for example, digitalis toxicity produces characteristic ECG findings.
6. Ventricular hypertrophy: Determining whether ventricular hypertrophy exists, which aids in diagnosing structural abnormalities of the heart.
