An ECG and a blood test are not the same thing: an ECG measures your heart’s electrical activity, while blood tests measure biochemical markers like cholesterol and blood sugar. Used together, they give a broader picture of cardiovascular risk than either alone.
What each test actually measures
| Test | What it measures | What it can flag |
|---|---|---|
| Electrocardiogram (ECG) | Electrical activity and rhythm of the heart | Irregular heartbeat (e.g. atrial fibrillation), heart block, signs of cardiac strain |
| Lipid panel | HDL, LDL, total cholesterol, triglycerides | Cardiovascular risk from cholesterol |
| Blood glucose + HbA1c | Blood sugar control | Diabetes risk, a major cardiovascular risk factor |
| CT coronary calcium score (if clinically indicated) | Arterial calcification | Structural cardiovascular risk beyond bloods/ECG |
Why HealthScreen combines them
Blood biomarkers show how your body is functioning chemically; an ECG shows how your heart is functioning electrically. Together they catch different categories of risk; a normal lipid panel doesn’t rule out a rhythm issue, and a normal ECG doesn’t rule out high cholesterol.
Common mistakes
- Assuming a normal ECG means no cardiovascular risk. It only assesses electrical rhythm at the time of testing, not arterial or metabolic risk, which is why it’s paired with blood work.
- Not fasting before the blood draw. HealthScreen requires fasting from midnight the night before, since eating affects glucose and lipid readings.
- Treating a single test as sufficient without considering a CT calcium score when risk factors (family history, age, lifestyle) are present.
Who should be tested
Anyone undertaking a comprehensive health screening should include both, since they answer different questions. It becomes more clinically relevant with family history of heart disease, high blood pressure, elevated cholesterol, or age-related cardiovascular risk. Your HealthScreen physician determines whether the CT calcium score is also clinically indicated.
Heart Health Testing FAQs
Is an ECG a type of blood test?
No. An ECG uses electrodes to record your heart’s electrical activity; it doesn’t involve a blood sample. Both are typically done in the same HealthScreen appointment.
What does an ECG detect that blood tests don’t?
Rhythm and electrical conduction issues, such as atrial fibrillation or heart block, which biochemical blood markers can’t show.
Do I need to fast before an ECG?
No fasting is required for the ECG itself, but fasting from midnight is required for the accompanying blood panel.
