Slide 1: A 53yo F presents for annual exam [ECG] What’s the major finding?

Slide 2: Left Bundle Branch Block. 1 QRS>120ms. 2 Deep S in V1. 3 Notched R in lateral leads.

Slide 3: A few days later… [ECG] She presents to the ED with atypical chest pain.

Slide 4: How do you explain the TWIs? How does her prior EKG change your approach?

Slide 5: Cardiac Memory. T-wave abnormalities that appear after a wide QRS rhythm narrows (eg LBBB, pacing). The longer the abnormal QRS, the longer cardiac memory persists. Findings suggestive of memory: 1. Positive T in aVL. 2. Positive/isoelectric T in I. 3. Precordial TWI > Inferior TWI

Slide 6: Takeaways! QRS abnormalities can result in memory T-waves. Cardiac memory can provide an alternate explanation for ‘scary’-looking EKGs. Always remember to consider clinical context and prior EKG history!


  • Shvilkin A, Huang HD, Josephson ME. Cardiac memory: diagnostic tool in the making. Circ Arrhythm Electrophysiol. 2015 Apr;8(2):475-82. PMID 25900990.

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