| RAVC | retrograde atrioventricular conduction; Royal Army Veterinary Corps |
|---|---|
| AC/BC | air conduction/bone conduction [time ratio] |
| IRMA | 1) Intra-Retinal Microvascular Abnormalities 2) Immuno-Radio-Metric Assay... |
| AGR | aniridia, genitourinary abnormalities, and mental retardation; anticipatory goal response |
| AUA | American Urological Association; asymptomatic urinary abnormalities |
| atrioventricular canal | The canal in the embryonic heart leading from the common sinuatrial chamber to the ventricle. (05 Mar 2000) |
|---|---|
| atrioventricular canal cushions | A pair of mounds of embryonic connective tissue covered by endothelium, bulging into the embryonic atrioventricular canal; located one dorsally and one ventrally, they grow together and fuse with each other and with the lower edge of the septum primum, dividing the originally single canal into right and left atrioventricular orifices. Synonym: endocardial cushions. (05 Mar 2000) |
| atrioventricular connections | The five distinct and discrete ways in which the atrial chambers may be connected to the ventricles are concordant, discordant, ambiguous, double inlet, and univentricular. (05 Mar 2000) |
| atrioventricular dissociation | Any situation in which atria and ventricles are activated and contract independently, as in complete A-V block, more specifically, the dissociation between atria and ventricles that results from slowing of the atrial pacemaker or acceleration of the ventricular pacemaker at nearly equal (rarely equal) rates, each depolarising its own chamber, thus interfering with depolarisation by the other (interference-dissociation). (05 Mar 2000) |
| atrioventricular extrasystole | An extrasystole arising from the "junctional" tissues, either the A-V node or A-V bundle. Synonym: junctional extrasystole. (05 Mar 2000) |
| atrioventricular gradient | The diastolic pressure difference between the atrium and ventricle. (05 Mar 2000) |
| atrioventricular groove | A groove on the outer surface of the heart marking the division between the atria and the ventricles. Synonym: sulcus coronarius, atrioventricular groove, atrioventricular sulcus, auriculoventricular groove, coronary sulcus. (05 Mar 2000) |
| atrioventricular interval | The time between depolarisation of the atria and of the ventricle. Synonym: atrioventricular interval. (05 Mar 2000) |
| atrioventricular junctional bigeminy | Paired beats, each pair consisting of an A-V nodal extrasystole coupled to a beat of the dominant, usually sinus, rhythm. Synonym: nodal bigeminy. (05 Mar 2000) |
| atrioventricular junctional rhythm | The cardiac rhythm when the heart is controlled by the A-V junction (including node); arising in the A-V junction, the impulse ascends to the atria and descends to the ventricles, each at varying speeds depending on site of the pacemaker. Synonym: A-V junctional rhythm, nodal bradycardia, nodal rhythm. (05 Mar 2000) |
| atrioventricular junctional tachycardia | Tachycardia originating in the A-V junction. Synonym: A-V junctional tachycardia, nodal tachycardia. (05 Mar 2000) |
| atrioventricular nodal branch | The atrioventricular branches or the nodal branches, the small arteries supplying the atrioventricular node; they usually arise from the right coronary artery where it starts to descend the posterior interventricular sulcus. Synonym: ramus nodi atrioventricularis, atrioventricular nodal branch, branch to atrioventricular node. (05 Mar 2000) |
| atrioventricular nodal extrasystole | A premature beat arising from the A-V junction and leading to a simultaneous or almost simultaneous contraction of atria and ventricles. (05 Mar 2000) |
| atrioventricular node | <cardiology> The location in the heart's conduction system, between the atria and the ventricles, which conducts the normal electrical impulse from the atria to the ventricles. (27 Sep 1997) |
| atrioventricular septum | The small part of the membranous septum of the heart just above the septal cusp of the tricuspid valve that separates the right atrium from the left ventricle. Synonym: septum atrioventriculare, pars membranacea septi atriorum. (05 Mar 2000) |