What is antidromic and orthodromic conduction?
An antidromic impulse in an axon refers to conduction opposite of the normal (orthodromic) direction. That is, it refers to conduction along the axon away from the axon terminal(s) and towards the soma.
What is orthodromic action potential?
Orthodromic action potentials evoked by synaptic excitation displayed similar changes in amplitude and shape. These observations lead to the conclusion that the soma, initial segment and neighbouring nodes of Ranvier contribute significantly to the shape of the action potential.
What is orthodromic nerve conduction?
Orthodromic technique. Stimulating electrodes are usually ring electrodes placed around the proximal and middle phalanxes of the 2nd or 3rd digits and the recording electrodes are placed on the ventral aspect of the wrist, over the median nerve, usually at about 1–2 cm proximal to the proximal wrist crease.
What is the advantages of antidromic sensory recording?
The major advantage of the antidromic approach reflects the recording site (the recording electrodes are on the digit). Because the tissue between the nerve fibers and the recording electrodes is minimal at this site, the amplitude of the response is much greater.
Is WPW antidromic vs orthodromic?
Types of arrhythmias in WPW are AVRT (80%). There are two type of AVRT, orthodromic (90 to 95%) vs. antidromic (5%), other types are atrial fibrillation (AF) (10% to 30%), atrial flutter, and ventricular tachycardia/ventricular fibrillation [4-7]. The different types of arrhythmias are shown in Figure 5.
What is antidromic stimulation?
Antidromic stimulation is performed to determine if a neuron that you are recording from projects to a particular region of the nervous system. You stimulate the axon of the neuron, and an action potential propagates backwards (antidromically) to the cell body, where recordings are occurring.
What is the definition antidromic?
Definition of antidromic : proceeding or conducting in a direction opposite to the usual one —used especially of a nerve impulse or fiber.
How is an antidromic action potential possible?
Electrical stimulation of the central nervous system creates both orthodromically propagating action potentials, by stimulation of local cells and passing axons, and antidromically propagating action potentials, by stimulation of presynaptic axons and terminals.
What is antidromic tachycardia?
Antidromic AVRT is a wide QRS complex (fully preexcited) tachycardia. In the presence of atrial tachycardia, atrial flutter, AF, or AVNRT, the QRS complexes can also be preexcited when the AP acts as a bystander and is not a critical part of the reentry circuit.
What is orthodromic WPW?
The WPW is an accessory pathway (AP) mediated tachycardia occurring in patients with ventricular pre-excitation on a 12-lead electrocardiogram (ECG).
What is orthodromic AVRT?
Orthodromic AVRT means that the ventricles are depolarized normally via the atrioventricular node and His-Purkinje system (Figure 3). Because the impulse reaches the ventricles through the His-Purkinje network the QRS complexes will appear normal (i.e QRS duration will be <0.12 s).
What is orthodromic tachycardia?
Orthodromic AVRT refers to a reentrant tachycardia that uses the AV node–His bundle axis as the antegrade limb and the AP as the retrograde limp (Figs. 15.7 and 15.8). Orthodromic AVRT accounts for more than 90% of AVRTs and 20% to 30% of all sustained SVTs. 26,27. The rate usually is 170 to 220 beats per minute.
Is Wolff-Parkinson-White syndrome orthodromic or antidromic?
Type A Wolff-Parkinson-White Syndrome Generating an Antidromic Atrioventricular (AV) Reentrant Tachycardia (AVRT) and an Orthodromic AVRT with a Long RP Interval Initiated only after Incomplete Impairment of an AV Accessory Pathway.
Is WPW orthodromic or Antidromic?
Only about 5% of the tachycardias in patients who have WPW syndrome are antidromic tachycardias; the remaining 95% are orthodromic.
How can you tell the difference between AVNRT and orthodromic AVRT?
Orthodromic AVRT, or just AVNRT? This rhythm can appear very similar to AVNRT, but the RP interval can assist us to differentiate: In typical AVNRT, retrograde P waves occur early, so we either don’t see them (buried in QRS) or partially see them (pseudo R’ wave at terminal portion of QRS complex)