Uma Mahesh R. Avula

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AIMS Atrial dilatation and myocardial stretch are strongly associated with atrial fibrillation (AF). However, the mechanisms by which the three-dimensional (3D) atrial architecture and heterogeneous stretch contribute to AF perpetuation are incompletely understood. We compared AF dynamics during stretch-related AF (pressure: 12 cmH(2)O) in normal sheep(More)
BACKGROUND Dominant frequencies (DFs) of activation are higher in the atria of patients with persistent than paroxysmal atrial fibrillation (AF), and left atrial (LA)-to-right atrial (RA) DF gradients have been identified in both. However, whether such gradients are maintained as long-term persistent AF is established remains unexplored. We aimed at(More)
BACKGROUND Little is known about the mechanisms underlying the transition from paroxysmal to persistent atrial fibrillation (AF). In an ovine model of long-standing persistent AF we tested the hypothesis that the rate of electric and structural remodeling, assessed by dominant frequency (DF) changes, determines the time at which AF becomes persistent. (More)
BACKGROUND Epicardial adiposity and plasma levels of free fatty acids (FFAs) are elevated in atrial fibrillation, heart failure and obesity, with potentially detrimental effects on myocardial function. As major components of epicardial fat, FFAs may be abnormally regulated, with a potential to detrimentally modulate electro-mechanical function. The cellular(More)
Coronary anatomy has traditionally focused on ventricular circulation. This is largely due to the extent to which coronary artery disease contributes to ischemic heart disease through ventricular myocardial damage. Atrial fibrillation and other tachyarrhythmias that involve the atria, however, remain a major cause of morbidity and mortality. In order to(More)
BACKGROUND The use of intracardiac electrograms to guide atrial fibrillation (AF) ablation has yielded conflicting results. OBJECTIVES The authors evaluated the usefulness of spatiotemporal dispersion, a visually recognizable electric footprint of AF drivers, for the ablation of all forms of AF. METHODS The authors prospectively enrolled 105 patients(More)
BACKGROUND Persistent atrial fibrillation (PAF) results in electromechanical and structural remodeling by mechanisms that are poorly understood. Myofibroblast proliferation and fibrosis are major sources of structural remodeling in PAF. Myofibroblasts also interact with atrial myocytes via direct physical contact and release of signaling molecules, which(More)
AIMS Transient ST-T elevation (STE) is a rare complication that occurs during transseptal catheterization. This study aims to delineate the incidence and characteristics of transient STE during transseptal catheterization for atrial fibrillation (AF) ablation. METHODS AND RESULTS Consecutive patients who underwent fluoroscopy-guided transseptal(More)