T wave memory/Chatterjee Phenomenon/Cardiac Memory

An elderly is admitted due to syncope. Is there MI or ischemia?

Trop here is negative. Have you heard of cardiac memory?

This pt had a pacemaker. The initial wides beats are paced beats. Then intrinsic beats. The intrinsic rhythm is AFl.

Cardiac memory refers to T-wave abnormalities the manifest on resumption of a normal activation pattern after a period of abnormal ventricular activation (ventricular pacing, transient LBBB, ventricular arrhythmias, or WPW. Pacing-induced T wave invetsion is usually localized in inferior and precordial leads. The direction of the T wave is the same as the direction of the QRS complex.

The combination of:
1- postitive T wave in aVL
2- postive of isolelectric T wave in I
3 - maxiaml precordial T wave inversion in III

... was 92% sensitive and 100% specific for cardiac memory, discriminating it from ischemic precorial T-wave inversion regardless of the coronary artery involved.

Barold SS et al. 2006. ECG Diagnois of MI and Ischemia during Cardiac Pacing. Cardio Clinics 24:387-399

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