When I first began my cardiology training, I felt reasonably confident reading ECGs—at least the straightforward ones. I could pick out sinus rhythm, atrial fibrillation, classic ST-elevation MI, and maybe the odd left bundle branch block. But when it came to the more nuanced strips—subtle ST depressions, early repolarization patterns, or multi-lead conduction abnormalities—I’d often find myself squinting at the paper for several minutes, second-guessing every blip. Occasionally, I’d even miss subtle but important lead changes altogether.
Meanwhile, the senior cardiologists around me seemed to have superpowers. They’d glance at an ECG for three seconds—sometimes even mid-conversation—and announce the diagnosis with pinpoint accuracy. I was baffled. Were they guessing? Was it instinct? Magic?
Eventually, I did what every frustrated trainee should do: I asked a professor.
The Professor’s Answer: “It’s All in the Images”
I asked my cardiology professor, “Why can’t I read ECGs as quickly as you do?”
He smiled and replied, “Because I’ve seen millions of them.”
He went on to explain something that completely changed how I approached ECGs: over the years, he had built a vast mental library of ECG patterns—stored as pictorial memory. His eyes automatically scanned for patterns that deviated from “normal.” When something didn’t fit the picture, his focus would immediately zoom in on the abnormality—like a radiologist spotting a nodule on a chest CT. There was no need to consciously go through rate, rhythm, axis, morphology, segment changes, and intervals. The diagnosis appeared almost reflexively, image to image.
What Medical School Taught Me vs. What Real Life Demands
In medical school, we were taught to read ECGs sequentially:
- Rate
- Rhythm
- Axis
- Morphology
- ST-segment
- Intervals (PR, QRS, QT)
This systematic approach is excellent for exams and fundamentals—but, in a real-world setting, especially during emergencies or high-volume clinics, this method becomes cumbersome. In time-sensitive decisions, spending five minutes on every ECG is simply not feasible.
How I Trained My Brain: The Visual Approach
Taking my professor’s advice to heart, I decided to create my own mental ECG atlas.
- I reviewed at least 50 ECGs for each of the common conditions (e.g., STEMI, atrial flutter, LBBB, WPW, etc.).
- For the rarer patterns—like Brugada, Wellens, trifascicular block—I made sure to study at least 20 variations.
- I paired this practice with a good ECG textbook (I used Rapid Interpretation of EKG’s by Dale Dubin and later Marriott’s Practical Electrocardiography) to solidify theory alongside visuals.
After about two months of daily practice, something interesting started to happen. My brain began to automatically match new ECGs to stored images in memory. When I saw a new ECG with trifascicular block, I didn’t need to dissect every lead. I could recognize the entire pattern within seconds, like recognizing a familiar face in a crowd.
The Key Takeaway
If you want to read ECGs at a glance, the secret is not some hidden algorithm or AI tool—it’s pattern recognition built through repetition. You must look at thousands of ECGs. With time, your brain will start mapping visual memory and doing near-instant pattern-matching, just like our senior mentors.
You don’t have to abandon the stepwise method—but once you’ve laid the foundation, it’s time to move beyond. Let your eyes and memory do the heavy lifting.
🧠 See more ECGs. Build the visual library. Recognize the patterns. That’s how you read ECGs faster.