BACKGROUND During atrial flutter, double potentials may be recorded at specific sites in the atria. It has been suggested that double potentials represent sequential activations at the center of the reentrant circuit. An alternative hypothesis is that double potentials represent electrical activity in an area of slow conduction. Understanding their mechanism is important because double potentia...

We investigated the event-related brain potentials elicited by arithmetical operations whose solution requires direct memory retrieval or non-retrieval strategies. The problem size effect--the increment in reaction time for arithmetical problems with large operands--appears to be due to the selective use of non-retrieval procedures, and studies with event-related potentials have demonstrated an...

Timing is a fundamental part of sensory and motor processing. However, little is known about the neural mechanisms underlying timing in the range of tens to hundreds of milliseconds. Although many theoretical hypotheses have been put forth on the possible underpinnings of temporal processing, there is little cellular experimental data, particularly in vitro, as to the neural mechanisms that cou...

Abnormal signal averaged electrocardiograms (SAECGs) and late ventricular potentials (LVPs) are predictors of sudden cardiac death. The present study hypothesized that SAECGs are impaired in hypertensive patients with renal failure. A total of 30 patients with grade 2 hypertension underwent SAECG. Serum level of creatinine and glomerular filtration rate (GFR) were also assessed. At least one SA...

Bullfrog ganglia contain two classes of neurone, B and C cells, which receive different inputs and exhibit different slow synaptic potentials. B cells, to which most effort has been directed, possess slow and late slow EPSPs. The sEPSP reflects a muscarinic action of acetylcholine released from boutons on B cells, whereas the late sEPSP is caused by a peptide (similar to teleost LHRH) released ...

In order to assess the occurrence and clinical significance of abnormal electrograms in idiopathic dilated cardiomyopathy, endocardial electrode mapping during sinus rhythm and programmed ventricular stimulation were performed in 52 patients with or without clinical ventricular tachycardia. Abnormal endocardial electrograms were recorded in 77% of the patients and were diffusely distributed ove...

I mproved methods for detecting individual patients recovering from myocardial infarction who are at high risk for sudden cardiac death are essential for reducing mortality from ventricular arrhythmias. During the past decade, many investigators have recorded low-amplitude, high-frequency waveforms and altered frequency components in the terminal QRS complex in laboratory animalsl2 and patients...

We propose a new class of quintessence models in which late times oscillations of a scalar field give rise to an effective equation of state which can be negative: wφ ≤ −1/3, and hence drive the observed acceleration of the universe. Currently favoured values Ωφ ∼ 0.7, ΩCDM ∼ 0.3 inferred from observations of high redshift supernovae can be easily accommodated by our model. A novel feature of o...

STUDY OBJECTIVE QT dispersion (QTd) and late potentials derived from signal-averaged ECG (SAECG) have been proposed as noninvasive predictors of cardiac arrhythmias that occur in patients with COPD. In this study, we aimed to investigate QTd and SAECG in patients with COPD. DESIGN Cross-sectional study. SETTING Teaching chest disease hospital and cardiology center in a university hospital. ...