OBJECTIVE In subsets of patients paroxysmal firing of ectopic foci in pulmonary veins or coronary sinus is an important cause of atrial fibrillation. This appears to represent a rare event overriding a dominant sinus mechanism to alter the rhythmic firing of the atrium. Hence, we tested the hypothesis that a rare stimulation pattern might alter the myocardial substrate, making it more susceptib...

Increased dispersion of repolarization has been suggested to underlie increased arrhythmogenesis in human heart failure (HF). However, no detailed repolarization mapping data were available to support the presence of increased dispersion of repolarization in failing human heart. In the present study, we aimed to determine the existence of enhanced repolarization dispersion in the right ventricu...

OBJECTIVE Mental or emotional stress-induced ventricular arrhythmias and sudden cardiac death are thought to be mediated by the autonomic nervous system and ischemia. In the absence of ischemia, increased inhomogeneity of repolarization is thought to be important. We tested the hypotheses that in the absence of ischemia, mental stress may modulate repolarization by changing autonomic balance; a...

BACKGROUND Recently we showed the predictive value of sum absolute QRST integral (SAI QRST) and repolarization lability for risk stratification of sudden cardiac death (SCD) in heart failure patients. The goal of this study was to compare SAI QRST and metrics of depolarization and repolarization variability in healthy men and women. METHODS Orthogonal ECGs were recorded at rest for 10 minutes...

Unipolar electrograms (EGs) and hybrid (or unorthodox or unipolar) monophasic action potentials (HMAPs) are currently the only proposed extracellular electrical recording techniques for obtaining cardiac recovery maps with high spatial resolution in exposed and isolated hearts. Estimates of the repolarization times from the HMAP downstroke phase have been the subject of recent controversies. Th...

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main source(s): TED2021-130459B-I00 LMP94_21 Introduction Left bundle branch area pacing (LBBAP) has been recently proposed to overcome the limitations associated with right ventricular (RVP) and suggested as a new physiological form high feasibility safety. A greater difference between QRS comple...

Background: QT duration represents the time of whole summated electric cardiac ventricular activity involving stepwise depolarization followed by repolarization. There has been a long history using surface electrocardiogram (ECG) to identify repolarization problems. The 1960s were turning point for precise mathematical methodologies. It customary in clinical practice use only interval and polar...