Common ECG Terms Explained
| Term | Meaning |
|---|---|
| Normal sinus rhythm | The heart's electrical activity follows the normal, expected pattern |
| Sinus bradycardia | Slower than normal heart rate (<60 bpm) — often normal in fit athletes |
| Sinus tachycardia | Faster than normal heart rate (>100 bpm) — can be due to anxiety, fever, dehydration, or heart conditions |
| Atrial fibrillation | Irregular heart rhythm — needs assessment for stroke risk |
| First-degree heart block | Mild delay in electrical conduction — often benign, monitored |
| Left/right bundle branch block | Delay in one side of the heart's conduction system — may need further investigation depending on context |
| ST elevation/depression | Can indicate heart muscle strain or damage — significant finding requiring urgent assessment if new |
| Left ventricular hypertrophy | Thickening of heart muscle — often related to long-standing high blood pressure |
What Happens After an Abnormal ECG
Not all abnormal findings are dangerous — many (like sinus arrhythmia or minor conduction delays) are benign variants requiring no action. Your doctor will interpret the finding in the context of your symptoms, risk factors, and other test results before deciding if further investigation (echocardiogram, 24-hour monitor, stress test) is needed.Always Get Context From Your DoctorAn ECG report alone, without clinical context, can be difficult even for non-cardiology doctors to fully interpret — always discuss your specific result with the doctor who ordered it, rather than searching for your exact terminology online.
Is a 'borderline' ECG something to worry about?
Often not — 'borderline' findings frequently reflect normal individual variation and don't necessarily indicate disease. Your doctor will advise if any follow-up is needed based on your overall clinical picture.
Why did I need an ECG if I feel fine?
ECGs are often done as routine screening (before surgery, as part of health checks) or to establish a baseline, not just in response to symptoms — many significant findings are picked up incidentally in people feeling well.
Can an ECG diagnose a heart attack that happened years ago?
Yes, sometimes — old, healed heart attacks can leave permanent changes visible on ECG (like Q waves), which can be an important clue even without current symptoms.
Medical Disclaimer: This page is for general education only and does not replace professional medical advice. Always consult a qualified healthcare provider.