In this episode, we’re breaking down the electrocardiogram—ECG or EKG (same thing).

This should be simple.

It is.And it isn’t.And it matters more than people think.

This is one of the most commonly used tools in medicine, but it’s also one of the most misunderstood when it comes to fundamentals.

We’ll cover:

* What an ECG actually measures

* What all the “squiggly lines” represent

* The basic complexes: P wave, QRS, and T wave

* How to read an ECG in a consistent, systematic way

* What each lead is really showing you (think: different camera angles)

* The difference between limb leads and precordial leads

* Why electrode placement is NOT optional if you want accurate data

Here is a clinical example inspired by The Pitt and how poor placement can miss a life-threatening diagnosis

Quotes you can’t argue with:

“Bad data is s**t data”

“Women are misdiagnosed for heart attacks all the time”

“It turns out women want to live”

“EKG is a great tool if you use it right”

Regarding electrode placement and breast tissue:

The current recommendations and available evidence: Kligfield et al., 2007 found that reproducibility of ECG measurements was slightly increased when electrodes were placed on top of the breast.

Another patient preference study (Wallen et al., 2014) found that 52% of women preferred on-breast placement, 38% were indifferent, and only 10% preferred under-breast placement.

Nonetheless, the current AHA/ACC/HRS guidelines suggest placing electrodes beneath the breast is the most common practice and is thought to reduce amplitude attenuation caused by higher torso impedance from overlying breast tissue. However, placing V4 under the breast can cause V5 and V6 to be positioned too inferiorly (below the horizontal plane of V4), which may alter voltage amplitudes used in diagnosing ventricular hypertrophy. Importantly, whichever method is used, consistency between serial ECGs is critical. If electrodes are placed under the breast, ensure V5 and V6 remain at the horizontal level of V4 rather than following the inframammary fold downward and in patients where intercostal space palpation is difficult (e.g., obesity), the sternal notch-to-xiphoid length can help locate the 4th intercostal space which is approximately 67% of the sternal notch-to-xiphoid distance.

UCSF PlaySafe Sports Medicine Program: https://playsafe.ucsf.edu/content/ucsf-playsafe-sports-medicine-program

UCSF PlaySafe Cardiac Physicals: https://playsafe.ucsf.edu/playsafe-cardiac-physicals

The Electrocardiogram at 100 Years: History and Future: https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.123.065489

The Invention of Electrocardiography Machine: https://pmc.ncbi.nlm.nih.gov/articles/PMC6881865/

Einthoven’s Triangle: https://aclscertification.org/acls-einthovens-triangle/

Please visit Life in the FastLane: https://litfl.com/ecg-library/basics/

My Favorite ECG books:

Rapid Interpretation of EKG’s, Sixth Edition 6th Edition by Dale Dubin

Sparkson’s Illustrated Guide to ECG Interpretation by Jorge Muniz

12-Lead ECG: The Art of Interpretation Second Edition by Tomas Garcia

EKGs for the Nurse Practitioner and Physician Assitant by Maureen Knechtel

ECG Mastery: the Simplest Way to Learn ECG by Kuhn, Lang, Wiesbauer

Produced by: Nadja Wlasiuk, DNP, APRN, FNP-BC, CCK

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