We propose a new model for RR interval records based on the empirical finding that the amplitude of RR records is negatively correlated with its regularity. We develop the mathematics needed to define rigorously this model, as well as the statistical tools necessary for estimating the parameters of the model on sampled data. We use this to analyze finely the impact of ventricular extrasystole o...

•We reviewed 185 PVC catheter ablation cases and identified 17 in which PVCs were successfully ablated in the aortic cusps.•The MDI measured 0.53 ± 0.10 (median 0.50, IQR 0.47-0.60).•In all (100%) cases MDI was > 0.40 and in 7 (41%) cases it was > 0.55.•Pseudo-delta wave was absent in all but one PVC•PVC origin in the aortic cusps should be considered along with the epicardium when MDI is in th...

The in vitro generation of a three-dimensional (3-D) myocardial tissue-like construct employing cells, biomaterials, and biomolecules is a promising strategy in cardiac tissue regeneration, drug testing, and tissue engineering applications. Despite significant progress in this field, current cardiac tissue models are not yet able to stably maintain functional characteristics of cardiomyocytes f...

Developing better methods for risk stratification for tachyarrhythmic sudden cardiac remains a major challenge for physicians and scientists. Since the transition from sinus rhythm to ventricular tachycardia/fibrillation happens by different mechanisms in different people, it is unrealistic to think that a single measure will be adequate to provide a good index for risk stratification. We analy...

Cardiac resynchronization therapy (CRT) has been shown to improve cardiac function, diminish hospitalization frequency, and enhance quality of life in selected heart failure patients. This benefit is mostly due to improved synchronization of ventricular contraction in the diseased heart. Since heart failure patients represent a heterogeneous group, cardiac resynchronization therapy must be tail...

BACKGROUND/AIMS Cell transplantation into the heart is a new therapy after myocardial infarction. Its success, however, is impeded by poor donor cell survival and by limited transdifferentiation of the transplanted cells into functional cardiomyocytes. A promising strategy to overcome these problems is the induction of cardiomyogenic properties in donor cells by small molecules. METHODS Here ...

To establish a murine model that may allow for definition of the precise role of phospholamban in myocardial contractility through selective perturbations in the phospholamban gene, we initiated studies on the role of phospholamban in the murine heart. Intact beating hearts were perfused in the absence or presence of isoproterenol, and quantitative measurements of cardiac performance were obtai...

The in vitro generation of a three-dimensional (3-D) myocardial tissue-like construct employing cells, biomaterials, and biomolecules is a promising strategy in cardiac tissue regeneration, drug testing, and tissue engineering applications. Despite significant progress in this field, current cardiac tissue models are not yet able to stably maintain functional characteristics of cardiomyocytes f...

This report describes the clinical course of a patient with bradycardia and tachycardia-dependent atrioventricular block. Bradycardia dependent A-V block (phase 4 block) was transient and precipitated by spontaneous slowing of the sinus rate, atrial and ventricular extrasystoles; The degree of slowing (critical RP interval) required to induce A-V block increased progressively over a three-day p...