Surface ECG criteria can discriminate post-septal pacing cardiac memory from ischemic T wave inversions.

Unlabelled: Cardiac memory (CM) refers to transient T wave changes that appear after cessation of a period of abnormal ventricular activation, such as right ventricular (RV) pacing. ECG criteria for differentiating post-pacing CM from ischemia-induced T wave changes were previously published only for apical, but not for septal RV pacing.

Aim: To find ECG criteria for discriminating post-septal pacing CM from ischemic T wave inversions.

Reproducibility of Combined Acquisition and Measurement of Left Ventricular Longitudinal Peak Segmental Strain in Relation to the Severity of Left Ventricular Dysfunction.

Background: Whether left ventricular (LV) longitudinal peak systolic segmental strain (LPSS) has sufficient reproducibility to be used in clinical practice (e.g., in patient follow-up) remains unclear.

Cardiac Memory - from Theory to Clinical Practice.

Cardiac memory (CM) is defined as changes in T wave polarity and vector that appear after cessation of a period of abnormal ventricular depolarization of various causes. The mechanisms responsible for CM development are initiation by local stretch, requiring myocardial contraction, followed by a cascade of intracellular signals that lead to a reduction in repolarization currents, especially Ito. In practice, CM is a frequently encountered ECG phenomenon, especially in patients with intermittent ventricular pacing, and knowledge of the ECG pattern of CM may help quick differential diagnosis from ischemia.

Regional Mechanical Changes Assessed by 2D Speckle-Tracking Longitudinal Strain do not Parallel Electrical Post-Pacing Cardiac Memory.

Background: Cardiac memory (CM) refers to persistent T-wave changes that appear after cessation of a period of abnormal ventricular activation, such as ventricular pacing. Prior animal studies using tagged magnetic resonance imaging have suggested that CM is associated with prolonged action potential duration and increased strain of late-activated myocardial segments.

Objective: The aim of the present study is to determine whether CM induced by ventricular pacing in human subjects is accompanied by regional mechanical changes in late-activated myocardial segments, assessed by left ventricular (LV) longitudinal strain (peak LS) and time-to-peak longitudinal strain (TTP-LS), using 2D-speckle tracking echocardiography (2DSE).

Right ventricular electrical and mechanical synchronization by properly timed septal pacing in a patient with right bundle branch block and first degree AV block--a case report.

We present a case of near-normalization of the QRS by septal pacing in a patient with dual-chamber pacemaker and underlying complete right bundle branch block and first degree atrioventricular block. The right ventricular mechanical synchronization suggested by the ECG was validated as such by strain echo. To the best of our knowledge, this is the first time it has been shown that the narrowing of the QRS corresponds to mechanical synchronization in a case of this seldom-recognized phenomenon.