The effects of chronic morphine administration on the development of long-term potentiation (LTP) were investigated at the Schaffer collateral-CA1 pyramidal cell synapses of the rat hippocampal slices using primed-bursts tetanic stimulation. Significant enhancement of orthodromic population spike (OPS) was found for all stimulus intensities after tetanic stimulation. OPS enhancement was greates...

OBJECTIVE To highlight the association between atrial flutter and accessory connections in the fetus and young infant. DESIGN A retrospective review from January 1985 to January 1990. PATIENTS Fetuses, neonates, and young infants with atrial flutter. RESULTS Four fetuses and five infants presented with atrial flutter. In two fetuses and one infant sinus rhythm returned spontaneously. The ...

We report a case of complex supraventricular tachycardia manifested by radiofrequency delivery. Initially, the patient presented with orthodromic atrioventricular reentrant tachycardia via a left-sided accessory pathway that was successfully eliminated. Atrial tachycardia originating from coronary sinus ostium was also induced. Radiofrequency delivery at the coronary sinus ostium induced a narr...

A 32-year-old man with a 20-year history of palpitation showed a short PQ interval and delta wave on 12-lead ECG. An electrophysiological study showed that the atrio-His (AH) and His-ventricular intervals were not influenced by rapid right atrial pacing or by bolus injection of adenosine triphosphate (ATP). The AH interval was shortened by coronary sinus ostium (CSos) pacing. Ventricular stimul...

The pattern of firing and responses to electrical stimulation of the ipsilateral vagus nerve were studied in respiratory neurons near the nucleus ambiguus (NA) in the region called "ventral respiratory nucleus". In 41 (out of 77) respiratory neurons orthodromic responses were recorded; the remaining neurons did not respond to stimulation. It is concluded that the NA neurons of the rabbit are no...

The anatomic location of atrioventricular (AV) bypass tracts (or accessory pathways) is variable, but these generally traverse the tricuspid or mitral annulus and insert into the atrium and ventricle near the AV ring. There is only 1 case report of an accessory pathway ablated in the left coronary cusp (LCC), and this pathway had bidirectional conduction, was not decremental, and was associated...

Normal values for the amplitudes of digital sensory nerve action potentials were obtained from 190 control subjects, using an orthodromic surface-recording technique. Lower limits were calculated, taking into account laterality, age and sex; the ratios of amplitudes between different digits were also estimated. The results in control subjects were compared with those of 20 cases of trauma invol...

In this project we invectigated bidirectional propagation of action potentials in giant axon of lobster Homarus americanus. We found an asymetrical propagation in the giant axons from the first two walking legs, which have claws. The backpropagating antidromic action potential decreases the conduction velocity when we increase the stimulation voltage, while the forward propagating (orthodromic)...

We report the case of a 46-year old patient in whom an electrophysiology study (EP) was performed due to paroxysmal supraventricular tachycardia documented in 12-lead ECG. During the EP study, supraventricular tachycardia was induced easily and it corresponded to orthodromic AV reentry tachycardia (AVRT) using a concealed left free wall accessory pathway. However, during the study AVRT spontane...