EKG: Learning Tips

Here is how I gained initial confidence with EKG during residency. Follow the steps below.

1. Establish a systematic approach and stick to it.
   Take time with this step. Think hard to design a system that makes sense to you. Use mnemonics to promote retention. Here are some examples/tips:

   • Remember “3” and “5” are magic numbers.

     • For rate, normal RR interval is 3-5 large blocks (HR 60-100).

     • For PR interval, normal is 3-5 small blocks (120-200 ms).

     • For QRS, normal is 3 small blocks (120 ms).

   • Design your eye tracking protocol that matches your system (eg, below protocol is like drawing a circle from the bottom, which matches “RRIAHS”)

     • Start with rhythm strip below to check Rate (RR), Rhythm (P-QRS relationship), Interval (PR, QRS, QT).

       • If you see widened QRS, glance at V1/V2 and V5/V6 to check for BBB.
         LBBB makes left leads [V5/v6] up and wide, RBBB makes right lead [V1/V2] up and wide - this can be explained by electrophysiology (waves slowly but continuously moving towards the blocked side).

     • Move to lead I/II to check Axis.

       • Remember: lead I and II are a couple. Right axis deviation = Kissing each other (because that’s Right!). Left axis deviation = Left each other.

       • What’s the purpose of checking axis? If not otherwise explained by hypertrophy/MI, they often suggest fascicular block (LAD = LAFB, RAD = LPFB; often there is also RBBB, suggesting conduction system disease) or WPW type (less common).

     • Move to lead V1/V2 and V5/V6 to check for Hypertrophy, and take a peek at aVL.

       • Magic number is “7” large blocks the sum of downward wave in V1/V2 + upward wave in V5/V6, and 2 (to be more specific 2.1) large blocks in aVL.

     • Move to all leads to check for Q-ST-T changes.

       • Correlate leads with walls

       • Focused reading on ST-T changes as below

2. Deliberate practice + spaced learning/repetition

   • 150 EKG Problems book and 150 EKG deliberate practice sheet. Practice 5 EKGs a day (write down your interpretation -> read the answer -> highlight learning points), and get comfortable with EKG in 30 days.

   • EKG wave-Maven is a more advanced resource if you want to pursue some expertise. The learning never ends but is rewarding!

3. Focused reading

   • ST elevation (CCJM review)

   • ST depression and T wave inversions (CCJM review)

   • OMI pocket guide (dedicated reference on STE mimics and STEMI equivalents)

4. Teach others!