| aphasia, conduction | A type of fluent aphasia in which there is normal comprehension of spoken language but words are repeated incorrectly. It results from a lesion of the arcuate fasciculus connecting broca's and wernicke's areas. Like patients with wernicke's aphasia (aphasia, wernicke), patients with conduction aphasia are fluent but have many paraphasic errors (incorrect words or sounds substituted for correct ones). The degree of fluency is less than that in wernicke's aphasia, but comprehension is good. (12 Dec 1998) |
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| atrioventricular conduction | Forward conduction of the cardiac impulse from atria to ventricles via the A-V node or any bypass tract, represented in the electrocardiogram by the P-R interval. P-H conduction time is from the onset of the P wave to the first high frequency component of the His bundle electrogram (normally 119 ± 38 msec); A-H conduction time is from the onset of the first high frequency component of the atrial electrogram to the first high frequency component of the His bundle electrogram (normally 92 ± 38 msec); P-A conduction time is from the onset of the P wave to the onset of the atrial electrogram (normally 27 ± 18 msec). (05 Mar 2000) |
| atrioventricular conduction abnormalities | <cardiology, physiology> Any condition which involves abnormal (blocked, delayed or aberrant) electrical conduction through the atrioventricular node (for example atrioventricular block). Some medications may precipitate atrioventricular conduction abnormalities. (02 Jan 1998) |
| avalanche conduction | <physiology> The discharge of an impulse from a neuron into a large number of neurons of the same physiologic system. This produces an amplification effect, thus producing a very large amount of nervous energy for a given stimulus. (05 Mar 2000) |
| A-V conduction | Forward conduction of the cardiac impulse from atria to ventricles via the A-V node or any bypass tract, represented in the electrocardiogram by the P-R interval. P-H conduction time is from the onset of the P wave to the first high frequency component of the His bundle electrogram (normally 119 ± 38 msec); A-H conduction time is from the onset of the first high frequency component of the atrial electrogram to the first high frequency component of the His bundle electrogram (normally 92 ± 38 msec); P-A conduction time is from the onset of the P wave to the onset of the atrial electrogram (normally 27 ± 18 msec). (05 Mar 2000) |
| A-V conduction abnormalities | <cardiology, physiology> Any condition which involves abnormal (blocked, delayed or aberrant) electrical conduction through the atrioventricular node (for example atrioventricular block). Some medications may precipitate atrioventricular conduction abnormalities. (02 Jan 1998) |
| bone conduction | The conduction of sound to the inner ear through the bones of the skull. (12 Dec 1998) |
| P-A conduction time | See: atrioventricular conduction. (05 Mar 2000) |
| ventricular conduction | Conduction of the cardiac impulse through the ventricular myocardium, represented by the QRS complex in the electrocardiogram. H-R conduction time is from the onset of the first high frequency component of the His bundle electrogram to the onset of the QRS complex of the surface electrocardiogram (normally 43 ± 12 msec); H-V conduction time is from the onset of the first high frequency component of the His bundle electrogram to the onset of the ventricular electrogram (normally approximates the H-R interval but may be a little shorter). Synonym: ventricular conduction. (05 Mar 2000) |
| ventriculoatrial conduction | Conduction backward from the ventricles or from the A-V node into and through the atria. Synonym: retroconduction, ventriculoatrial conduction, V-A conduction. (05 Mar 2000) |
| retrograde conduction | Conduction backward from the ventricles or from the A-V node into and through the atria. Synonym: retroconduction, ventriculoatrial conduction, V-A conduction. (05 Mar 2000) |
| P-H conduction time | See: atrioventricular conduction. (05 Mar 2000) |
| concealed conduction | Conduction of an impulse through a part of the heart without direct evidence of its presence in the electrocardiogram; conduction is inferred only because of its influence on the subsequent cardiac cycle. (05 Mar 2000) |
| conduction | <physics, physiology> The transfer of sound waves, heat, nervous impulses or electricity. Origin: L. Conductio (18 Nov 1997) |
| conduction anaesthesia | Regional anaesthesia in which local anaesthetic solution is injected about nerves to inhibit nerve transmission; includes spinal, epidural, nerve block, and field block anaesthesia, but not local or topical anaesthesia. Synonym: block anaesthesia. (05 Mar 2000) |