Cardiac memory … new insights into molecular mechanisms

Abstract

'Cardiac memory' describes an electrocardiographic T wave vector change, recorded during normal sinus rhythm that reflects the QRS complex vector during prior periods of ventricular pacing or arrhythmia. In this brief review we consider the mechanisms responsible for cardiac memory, which offer a unique window for relating molecular determinants of repolarization to their expression in the function of ion channels and in the electrophysiology of the heart. Understanding the steps that translate the molecular mechanisms for memory into clinical expression in this relatively straightforward model facilitates our comprehension of the complex pathways that order normal cardiac repolarization and repolarization changes.

Complexes of Angiotensin IV with Functionally Different Proteins in the Regulation of Drinking Behavior and Hemodynamics in Rats

“…There are confl icting data on the action of free AT-IV on SBP. It should be emphasized that previous studies were mainly performed on experimental models of isolated blood vessels (vasodilation and vasoconstriction) [5,[10][11][12][13]. Our experiments on awake animals (n=10) demonstrated the hypotensive effect of this peptide.…”

“…Activity of AT-IV is manifested in the neurotrophic effect and modulation of learning (model of defensive behavior). The results of previous studies suggest that AT-IV is involved in memory fi xation at the molecular genetic level under various pathological conditions (atherosclerosis, hypertension, and memory disorders) [5,9,[11][12][13][14].…”

National Russian Guidelines on Application of the Methods of Holter Monitoring in Clinical Practice

“…Позднее данный феномен получил название долгосрочной "памяти сердца", т. к. была выявлена связь данных изменений с комплексом электрофизио логических характеристик работы сер-дца и молекулярными механизмами работы ионных каналов [543]. Более поздние исследования объяс-няют регистрацию электрофизиологической неод-нородности волны Т эволюцией трансмурального градиента реполяризации [544].…”

“…К имплантируемым антиаритмическим устройст-вам (ИАУ) в настоящее время относятся [536][537][538][539][540][541][542][543][544][545]:…”

Precordial T-wave inversion of “cardiac memory” pattern after high-dose methylprednisolone pulse therapy

“…Whether the electrophysiological changes of CM have developed following preceeding cardiac arrhythmia of corticosteroid pulse therapy (which may have already spontaneously disappeared) or if the observed TWI is a direct alteration caused by corticosteroids in the heart's conduction system remains unknown. Mechanisms postulated for CM include effects of angiotensin II on transient outward current (Ito) of myocytes [17] with changes in Kv4.3 trafficking with angiotensin II-activated AT1 receptor into endocytic vesicles [18], affecting transient outward current [19]. Interestingly enough, high-dose glucocorticoids have nongenomic effects on membrane channels, and hence on heart electrophysiology [20][21][22].…”