Association of electrocardiographic spatial heterogeneity of repolarization and spatial heterogeneity of atrial depolarization with left ventricular fibrosis.

Aims: To evaluate the relationship between spatial heterogeneity of electrocardiographic repolarization and spatial heterogeneity of atrial depolarization with arrhythmic substrate represented by left ventricular fibrosis.

Methods And Results: We assessed the associations of T- and P-wave morphology parameters analysed from the standard 12-lead electrocardiograms with left ventricular fibrosis in 378 victims of unexpected sudden cardiac death (SCD) who underwent medico-legal autopsy. Based on autopsy findings, the SCD victims were categorized into four different groups according to different stages of severity of left ventricular fibrosis (substantial fibrosis, moderate patchy fibrosis, scattered mild fibrosis, no fibrosis).

Association of atrial depolarization variability and cardiac autonomic regulation with sudden cardiac death in coronary artery disease.

Aims: To evaluate the prognostic significance of the temporal variability of P-wave morphology, specifically in relation to cardiac autonomic regulation.

Methods And Results: We analyzed the standard deviation of P-wave residuum (PWRSD) from five consecutive beats of the standard 12-lead ECG in 1236 patients with angiographically verified coronary artery disease (CAD). We evaluated the prognostic value of PWRSD, of PWRSD and PWR in relation to the 24 h standard deviation of normal-to-normal intervals (PWRSD/SDNN and PWR/SDNN).

Increased Beat-to-Beat Variability of T-Wave Heterogeneity Measured From Standard 12-Lead Electrocardiogram Is Associated With Sudden Cardiac Death: A Case-Control Study.

Introduction: The prognostic significance of beat-to-beat variability of spatial heterogeneity of repolarization measured from standard 12-lead ECG is not well-understood.

Methods: We measured the short-term variability of repolarization parameters, such as T-wave heterogeneity in leads V4-V6 (TWH) and QT interval (QT), from five consecutive beats of previously recorded standard 12-lead ECG in 200 victims of unexpected sudden cardiac death (SCD) confirmed to be due to complicated atherosclerotic coronary artery disease (CAD) in medico-legal autopsy and 200 age- and sex-matched controls with angiographically confirmed CAD. The short-term variability of repolarization heterogeneity was defined as the standard deviation (SD) of the measured repolarization parameters.