Cardiac memory: mechanisms and clinical implications.
Cardiac memory (CM) is identified as an altered T wave on electrocardiogram and vectorcardiogram that is seen when sinus rhythm resumes after a period of abnormal myocardial activation. Specifically, the sinus rhythm T wave tracks the QRS vector of the abnormal impulse. CM frequently is induced by ventricular pacing or arrhythmias and historically has been considered of minor relevance to medical practice. Although it has long been known that CM can mimic the T-wave inversions of myocardial ischemia, we learned more recently that CM can alter the actions of antiarrhythmic drugs. Furthermore, it provides a template for investigating the mechanisms whereby ventricular pacing affects myocardial physiology. In this article we review the mechanisms believed responsible for induction of CM and some of its more recently recognized clinical manifestations. We also discuss the controversies regarding atrial memory and its potential clinical implications.
Patberg
Kornelis W
KW
Department of Pharmacology, College of Physicians and Surgeons of Columbia University, New York, New York 10032, USA.
Shvilkin
Alexei
A
Plotnikov
Alexei N
AN
Chandra
Parag
P
Josephson
Mark E
ME
Rosen
Michael R
MR
D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology; D002304:Cardiac Pacing, Artificial; D004562:Electrocardiography; D006329:Heart Conduction System / Q000503:physiopathology*; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D020257:Ventricular Remodeling / Q000502:physiology*
D000889:Anti-Arrhythmia Agents