Dennis L. Rollins

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The characteristics of spontaneous cardiac arrhythmias leading to sudden cardiac death are largely unknown. To study arrhythmias in animal models, an eight-channel implantable radio telemetry system has been developed to record continuously cardiac electrograms over a period of weeks to months, with maintenance restricted to changing batteries. The inputs(More)
OBJECTIVE To characterize the effects of stimulation of the nerve of Hering (HN; cranial nerve nine) in controlling seizure activity using a canine model. METHODS Using penicillin applied topically to a region of the cerebral cortex, 16 seizure-type continuous epileptiform discharges were generated. Ten specimens of HN (five left-sided and five(More)
It has been hypothesized that during ventricular fibrillation (VF), the fastest activating region, the dominant domain, contains a stable reentrant circuit called a mother rotor. This hypothesis postulates that the mother rotor spawns wavefronts that propagate to maintain VF elsewhere and implies that the ratio of wavefronts propagating off a region to(More)
The purpose of this study was to determine the spatial changes in the transmembrane potential caused by extracellular electric field stimulation. The transmembrane potential was recorded in 10 guinea pig papillary muscles in a tissue bath using a double-barrel microelectrode. After 20 S1 stimuli, a 10-ms square wave S2 shock field with a 30-ms S1-S2(More)
OBJECT Vagus nerve stimulation is known to decrease the frequency, duration, and intensity of some types of intracranial seizures in both humans and animals. Although many theories abound concerning the mechanism for this action, the true cause remains speculative. To potentially elucidate a pathway in which vagus nerve stimulation aborts seizure activity,(More)
We have previously shown that left-sided vagus nerve stimulation results in cessation of induced spinal cord seizures. To test our hypothesis that right-sided vagus nerve stimulation will also abort seizure activity, we have initiated seizures in the spinal cord and then performed right-sided vagus nerve stimulation in an animal model. Four pigs were(More)
We have developed a sonomicrometer and continuous wavelength (CW) Doppler flowmeter for a multichannel telemetry system. These developments will enable us to measure ventricular dimension and coronary artery blood velocity, which are valuable parameters to characterize sudden cardiac death (SCD) in ambulatory animal models of ventricular arrhythmias. The(More)
OBJECTIVE To determine a solution capable of discerning adipose versus nervous tissue, to aid in surgical separation of the adipose tissue which appears to be visually indistinguishable from nervous tissue in lipomyelomeningoceles (LMMs). METHODS The following solutes (in normal saline) were investigated, both at 25 and 37 degrees C: beta-carotene,(More)
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