Short answer: A normal ECG tells you a lot about your heart rate and rhythm, but it can’t answer every heart question on its own. Imaging cardiologist Dr. Johann Christopher said the ECG is very sensitive but not specific, except for rate and rhythm, so your doctor may still suggest more tests, built step by step on your history, examination, ECG and echo.
“They said the ECG is normal. So why do I still feel something is wrong?”
An ECG is often the first report you’re handed in a clinic or emergency room. Seeing the word “normal” brings relief, until the tightness, the unusual tiredness or the family history comes back to mind.
Many of us have also heard a story like this: someone’s ECG was normal, and the next day they were in hospital with a heart attack. So what does a normal ECG actually tell you, and what can’t it tell you?
In our Dil Ke Doubts session on heart tests, Heart Health India Foundation founder Ram Khandelwal, who had his own heart attack at 33, put this to imaging cardiologist Dr. Johann Christopher, Senior Consultant in Interventional Cardiology and Director of Cardiac Imaging at CARE Hospitals, Hyderabad, and Convener of the CSI Multimodality Imaging Council.
This article is based on the questions and answers in Dil Ke Doubts Webinar 09 (15 Sep 2026), part of Heart Health India Foundation’s World Heart Month 2026 series with the Cardiological Society of India and the World Heart Federation‘s Don’t Miss a Beat campaign.
Here’s what he told us, in plain words.
What is an ECG, and what is it best at?
Dr. Christopher called the ECG an electrical map of the heart. He said there are two jobs it does extremely well:
- Heart rate: whether your heart is beating at 60, 70, 80 and so on
- Rhythm problems: telling apart patterns such as SVT, ventricular tachycardia, sinus tachycardia (a fast normal rhythm) and sinus bradycardia (a slow normal rhythm)
In these two situations, he said, the ECG is a very good discriminator.
Why did doctors once read so much into an ECG?
About 20 years ago, he explained, when advanced imaging wasn’t available, senior doctors had only the ECG. So they used it to guess at a lot: the size of the heart’s chambers, valve disease, ischaemia (reduced blood supply to the heart muscle) and thickening of the heart muscle. Being able to read an ECG almost defined who was a cardiologist.
Then came the echo, and after it CT, MRI and nuclear scans. What used to be read on an ECG as “strain” or “ischaemia” turned out to overlap with other conditions too, including myocarditis (inflammation of the heart muscle). As he put it, it’s not anybody’s fault; it was a limitation of the technology at the time.
My ECG was normal. Why might I still need more tests?
Dr. Christopher’s plain summary: the ECG is very sensitive, so it picks up a lot of changes, but it is not specific, except for rate and rhythm. It simply doesn’t have the power to answer every heart question on its own.
So if someone you love had a normal ECG and then had a serious heart problem the next day, it doesn’t always mean the first test was “wrong”. It may mean the ECG was never meant to carry the whole diagnosis alone, and that further tests may still be needed based on symptoms and examination. In our Webinar 10 session, cardiologist Dr. Biswaranjan Mishra made a related point: an ECG can look normal even during a heart attack. Read more in gas or heart attack: how to know if chest pain is serious.
What tests can come after an ECG?
Dr. Christopher briefly described the three advanced tools he uses routinely:
- Coronary CT: excellent for the anatomy of the heart, and especially good for looking at the coronary arteries.
- Nuclear scan: not good for anatomy, but very good for function: how the heart pumps, heart volumes, ischaemia and scarring. It uses a radioisotope rather than a contrast dye. He said it is safe even in people with chronic kidney disease (CKD), but it involves radiation.
- Cardiac MRI: very good for structure, function, perfusion (blood flow to the muscle) and tissue detail. He called it “a one-stop shop” for cardiac imaging.
Can everyone have a cardiac MRI?
Not always. Dr. Christopher explained that cardiac MRI uses gadolinium, which is neither the usual iodine-based contrast nor a radioisotope. He said it is very kidney-sensitive and “cannot be used when the GFR is less than 40“. GFR is a measure of how well your kidneys are filtering. If you have kidney disease, tell your doctor before any scan, and ask which test suits you.
Which heart test should come first?
This was his most important line for patients. Advanced scans don’t replace the basics. The path to advanced imaging is still a good history, a careful clinical examination, a baseline ECG and a baseline echo. Then tests are added layer by layer. In his words, they “are not competitors to each other”. Without the basic history, he said, even a good-quality MRI can point to a completely different diagnosis.
For a simple overview of what each common test is for, see understanding your heart tests. And on why it helps to check early, read why preventive tests matter long before symptoms appear.
What you can do next
- If you have chest discomfort right now, don’t wait on an old “normal” ECG. Go to the nearest hospital. Our guide to recognising heart attack warning signs explains what to watch for.
- If you still have symptoms after a “normal” ECG, tell the doctor what you feel in your own words. Don’t apologise for worrying.
- Ask: “Do I need an echo next? Is there a reason to go further?”
- If you have kidney disease, mention it before any scan with contrast.
- Keep your previous ECG and test reports together and take them to appointments, so your doctor can see your history.
- Explore more sessions on our Dil Ke Doubts World Heart Month 2026 page, and read our earlier post on the Lp(a) test.
Frequently asked questions
Heart rate and rhythm, according to Dr. Johann Christopher. He called the ECG an electrical map of the heart.
Not always. He explained that the ECG is very sensitive but not specific except for rate and rhythm, so further tests may still be needed based on your symptoms and examination.
A good history and clinical examination, a baseline ECG and a baseline echo, then advanced imaging such as coronary CT, a nuclear scan or cardiac MRI if needed, added layer by layer.
Dr. Christopher said cardiac MRI uses gadolinium, is very kidney-sensitive and cannot be used when the GFR is less than 40. Tell your doctor about any kidney problem before a scan.
In the session, coronary CT was described as excellent for anatomy and the coronary arteries, a nuclear scan as strong for function, ischaemia and scar, and cardiac MRI as very good for structure, function, perfusion and tissue.
Watch the full session
Want to hear it from Dr. Christopher himself? The full Dil Ke Doubts session is below. His ECG answer starts at about 18:00.
▶️ Watch the full session: Diagnostics — Understanding Your Heart Tests · Please also Subscribe on YouTube @hearthealthindia.
In Dr. Christopher’s words: “You should always remember the path to advanced imaging is through a good history, a reliable clinical examination, a baseline ECG, a baseline echo and then you would add these things layer by layer. They themselves are not competitors to each other, but they are complementary.”
Authoritative sources (for further reading)
These links support general education about heart tests. They do not replace Dr. Christopher’s words in the session above, and they are not a personal diagnosis.
- MedlinePlus — Electrocardiogram
- NHLBI (NIH) — Heart tests
- NHS — Electrocardiogram (ECG)
- European Society of Cardiology — Guidelines hub
- Cardiological Society of India
About this article
Disclaimer: The medical information in this article is based only on the views shared by the session speaker, Dr. Johann Christopher. It is for educational purposes only and is not medical advice. Please consult your cardiologist for advice personalised to you. In an emergency, go to the nearest hospital immediately. See also our medical disclaimer.
You don’t have to figure this out alone
Heart Health India is a community of patients, families and caregivers learning together, with India’s cardiologists, how to look after our hearts. If a test report has left you with more questions than answers, come ask them, share what you’re going through, and hear from people who’ve been there.
