Search results for "P wave"
showing 2 items of 32 documents
P-Wave Indices: Derivation of Reference Values from the Framingham Heart Study
2010
P wave indices constitute an intermediate, phenotype reflecting the impact of ischemic, metabolic and inflammatory insults on atrial electrophysiology and morphology. Measured from the surface electrocardiogram (ECG), they reflect dimensions of atrial depolarization and are modified by conditions that alter atrial conduction, atrial refractoriness, or may result in a proarrhythmic substrate. The P wave indices of duration and dispersion have most commonly been measured. An array of studies have utilized these P wave indices to distinguish subjects with diverse cardiovascular and non-cardiovascular conditions and diseases from healthy reference groups.(1) Computerized software has more recen…
Disrupting neural activity related to awake-state sharp wave-ripple complexes prevents hippocampal learning
2012
Oscillations in hippocampal local-field potentials (LFPs) reflect the crucial involvement of the hippocampus in memory trace formation: theta (4–8 Hz) oscillations and ripples (~200 Hz) occurring during sharp waves are thought to mediate encoding and consolidation, respectively. During sharp wave-ripple complexes (SPW-Rs), hippocampal cell firing closely follows the pattern that took place during the initial experience, most likely reflecting replay of that event. Disrupting hippocampal ripples using electrical stimulation either during training in awake animals or during sleep after training retards spatial learning. Here, adult rabbits were trained in trace eyeblink conditioning, a hippoc…