Clinical Benefit of Ablating Localized Sources for Human Atrial Fibrillation: The Indiana University FIRM Registry.

Background: Mounting evidence shows that localized sources maintain atrial fibrillation (AF). However, it is unclear in unselected "real-world" patients if sources drive persistent atrial fibrillation (PeAF), long-standing persistent atrial fibrillation (LPeAF), or paroxysmal atrial fibrillation (PAF); if right atrial sites are important; and what the long-term success of source ablation is.

Objectives: The aim of this study was to analyze the role of rotors and focal sources in a large academic registry of consecutive patients undergoing source mapping for AF.

Diurnal variability in orthostatic tachycardia: implications for the postural tachycardia syndrome.

Patients with POTS (postural tachycardia syndrome) have excessive orthostatic tachycardia (>30 beats/min) when standing from a supine position. HR (heart rate) and BP (blood pressure) are known to exhibit diurnal variability, but the role of diurnal variability in orthostatic changes of HR and BP is not known. In the present study, we tested the hypothesis that there is diurnal variation of orthostatic HR and BP in patients with POTS and healthy controls.

Regulation of secretory protein expression in mature cells by DIMM, a basic helix-loop-helix neuroendocrine differentiation factor.

During differentiation, neuroendocrine cells acquire highly amplified capacities to synthesize neuropeptides to overcome dilution of these signals in the general circulation. Once mature, the normal functioning of integrated physiological systems requires that neuroendocrine cells remain plastic to dramatically alter neuropeptide expression for long periods in response to hormonal and electrical cues. The mechanisms underlying the long-term regulation of neuroendocrine systems are poorly understood.