WordNet

used to express refusal or denial or disagreement etc or especially to emphasize a negative statement; "no, you are wrong"
a negative; "his no was loud and clear"
referring to the degree to which a certain quality is present; "he was no heavier than a child" (同)no more
not in any degree or manner; not at all; "he is no better today"
quantifier; used with either mass nouns or plural count nouns for indicating a complete or almost complete lack or zero quantity of; "we have no bananas"; "no eggs left and no money to buy any"; "have you no decency?"; "did it with no help"; "Ill get you there in no time"
sway gently back and forth, as in a nodding motion; "the flowers were nodding in the breeze"
be almost asleep; "The old man sat nodding by the fireplace"
let the head fall forward through drowsiness; "The old man was nodding in his chair"
the act of nodding the head
a sign of assent or salutation or command
express or signify by nodding; "He nodded his approval"
lower and raise the head, as to indicate assent or agreement or confirmation; "The teacher nodded when the student gave the right answer"
any thickened enlargement (同)knob, thickening
(botany) the small swelling that is the part of a plant stem from which one or more leaves emerge (同)leaf node
a connecting point at which several lines come together
(computer science) any computer that is hooked up to a computer network (同)client, guest
(astronomy) a point where an orbit crosses a plane
(physics) the point of minimum displacement in a periodic system
any bulge or swelling of an anatomical structure or part
relating to or affecting the atria and ventricles of the heart; "atrioventricular disease" (同)auriculoventricular

PrepTutorEJDIC

《名詞の前に置いて》『一つも』(『一人も,少しも』)・・・『ない』 / 《補語につけて》『決して・・・でない』 / 《省略文で》・・・なし;・・・お断り / 《話》少ししか(あまり)・・・ない / (肯定の問いに対して)『いいえ』;(否定の問いに対して)はい,ええ / 《not, norの前に挿入して》『いや』,否 / 《形容詞の前に置その形容詞を否定して》…どころではない / 《比較級の前に置いて》ちっとも…でない,…と全く同じ / 《… or no の形で》…であってもなくても / 《驚き・困惑・不信などを表して》とんでもない / 《単数形で》『拒否』,「『いいえ』」という返事 / 《複数形で》反対[投]票
(承諾・あいさつ・合図などで)『うなずく』,会釈する / (眠くて)『こっくりする』,(油断して)うとうとする《+off》 / 〈草木・穂などが〉揺れる / (承諾・あいさつなどで)〈頭〉‘を'『うなずかせる』 / …‘を'うなずいて示す / 《副詞[句]を伴って》〈人〉‘に'うなずいて示す / 《同意・承諾・あいさつ・命令など,また時には拒絶を表して》(…に対する)『うなずき』,『会釈』《+『to』+『名』》;(眠気による)こっくり
(茎・幹の)節(ふし) / (体組織にできた)結節,こぶ(リンパ瘤(りゅう)など) / (天体の軌道の)交点 / (物事の)中心点

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/07/05 11:42:51」(JST)

wiki en

The atrioventricular node (abbreviated AV node) is a part of the electrical control system of the heart that coordinates the top of the heart. It electrically connects atrial and ventricular chambers.^[1] The AV node is an area of specialized tissue between the atria and the ventricles of the heart, specifically in the posteroinferior region of the interatrial septum near the opening of the coronary sinus, which conducts the normal electrical impulse from the atria to the ventricles. The AV node is quite compact (~1 x 3 x 5 mm).^[2] It is located at the center of Koch's Triangle—a triangle enclosed by the septal leaflet of the tricuspid valve, the coronary sinus, and the membraneous part of the interatrial septum.^[3]

Structure

The AV node receives two inputs from the atria: posteriorly, via the crista terminalis, and anteriorly, via the interatrial septum.^[4]

Blood supply

The blood supply of the AV node is via the AV nodal artery. The origin of this artery is most commonly (about 90% of hearts) a branch of the right coronary artery, with the remainder originating from the left circumflex artery.^[5]^[6]^[7] This is associated with the dominance of the coronary artery circulation. In right-dominant individuals the blood supply is from the right coronary artery while in left dominant individuals it originates from the left circumflex artery.

Development

BMP (Bone morphogenetic protein) cell signaling plays a key role in diverse aspects of cardiac differentiation and morphogenesis. (BMPs) are multifunctional signaling molecules critical for the development of AV node. BMP influences AV node development through Alk3 receptor (Activin receptor-like kinase 3). Abnormalities seen in BMP and Alk3 are associated with some cardiovascular diseases like Ebstein’s anomaly and AV conduction disease.^[8]

Function

Contraction of myocytes (heart muscle cells) requires depolarization and repolarization of their cell membranes. Movement of ions across cell membranes causes these events. The cardiac conduction system (and AV node part of it) coordinates myocyte mechanical activity. A wave of excitation spreads out from the sinoatrial node through the atria along specialized conduction channels. This activates the AV node.^[1] The atrioventricular node delays impulses by approximately 0.12s. This delay in the cardiac pulse is extremely important: It ensures that the atria have ejected their blood into the ventricles first before the ventricles contract.^[9]

This also protects the ventricles from excessively fast rate response to atrial arrhythmias (see below).^[10]

AV conduction during normal cardiac rhythm occurs through two different pathways:

the first “pathway” has a slow conduction velocity but shorter refractory period
the second “pathway” has a faster conduction velocity but longer refractory period.^[11]

An important property that is unique to the AV node is decremental conduction,^[12] in which the more frequently the node is stimulated the slower it conducts. This is the property of the AV node that prevents rapid conduction to the ventricle in cases of rapid atrial rhythms, such as atrial fibrillation or atrial flutter.

The AV node's normal intrinsic firing rate without stimulation (such as that from the SA node) is 40-60 times/minute.^[13]

Clinical relevance

Atrioventricular conduction disease (AV block) describes impairment of the electrical continuity between the atria and ventricles. It occurs when the atrial depolarization fail to reach the ventricles or is conducted with a delay. It can result from an injury or be a genetically inherited disorder.^[14]
Atrioventricular nodal re-entry tachycardia.^[11]
Cystic tumour of atrioventricular nodal region (CTAVN) CTAVN is of endodermal origin and occurs exclusively in the area of the AV node, tricuspid valve, and interatrial septum.^[15]

References

^ ^a ^b Gray, Huon H.; Keith D. Dawkins, Iain A. Simpson and John M. Morgan (2002). Lecture Notes on Cardiology. Boston: Blackwell Science. p. 135. ISBN 978-0-86542-864-5. Cite uses deprecated parameters (help)
^ Full Size Picture triangle of-Koch.jpg. Retrieved on 2008-12-22
^ Harrison's Principles of Internal Medicine, 17e” Section 3: Disorders of Rhythm
^ Fuster V, Rydén LE, Asinger RW, et al. (October 2001). "ACC/AHA/ESC guidelines for the management of patients with atrial fibrillation". Journal of the American College of Cardiology 38 (4): 1231–66. doi:10.1016/S0735-1097(01)01587-X. PMID 11583910.
^ Van der Hauwaert LG, Stroobandt R, Verhaeghe L (October 1972). "Arterial blood supply of the atrioventricular node and main bundle". British Heart Journal 34 (10): 1045–51. doi:10.1136/hrt.34.10.1045. PMC 458545. PMID 5086972.
^ Pejković, B.; Krajnc, I.; Anderhuber, F.; Kosutić, D. (2008). "Anatomical aspects of the arterial blood supply to the sinoatrial and atrioventricular nodes of the human heart". The Journal of international medical research 36 (4): 691–698. PMID 18652764. edit
^ Saremi, F.; Abolhoda, A.; Ashikyan, O.; Milliken, J. C.; Narula, J.; Gurudevan, S. V.; Kaushal, K.; Raney, A. (2007). "Arterial Supply to Sinuatrial and Atrioventricular Nodes: Imaging with Multidetector CT". Radiology 246 (1): 99–107; discussion 108–9. doi:10.1148/radiol.2461070030. PMID 18024438. edit
^ Stroud DM, Gaussin V, Burch JB, et al. (November 2007). "Abnormal Conduction and Morphology in the Atrioventricular Node of Mice With Atrioventricular Canal–Targeted Deletion of Alk3/Bmpr1a Receptor". Circulation 116 (22): 2535–43. doi:10.1161/CIRCULATIONAHA.107.696583. PMC 2947829. PMID 17998461.
^ Campbell, N., & Reece, J. (2002). Biology. 6th ed. San Francisco: Benjamin Cummings^{[page needed]}
^ Gray, Huon H.; Keith D. Dawkins, Iain A. Simpson and John M. Morgan (2002). Lecture Notes on Cardiology. Boston: Blackwell Science. p. 136. ISBN 978-0-86542-864-5. Cite uses deprecated parameters (help)
^ ^a ^b Gray, Huon H.; Keith D. Dawkins, Iain A. Simpson and John M. Morgan (2002). Lecture Notes on Cardiology. Boston: Blackwell Science. p. 157. ISBN 978-0-86542-864-5. Cite uses deprecated parameters (help)
^ Patterson E, Scherlag BJ (October 2002). "Decremental conduction in the posterior and anterior AV nodal inputs". Journal of Interventional Cardiac Electrophysiology 7 (2): 137–48. doi:10.1023/A:1020833604423. PMID 12397223.
^ Guyton, Arthur C.; John E. Hall (2006). Textbook of Medical Physiology (11 ed.). Philadelphia: Elsevier Saunders. p. 120. ISBN 0-7216-0240-1.
^ Benson DW (October 2004). "Genetics of atrioventricular conduction disease in humans". The Anatomical Record. Part A: Discoveries in Molecular, Cellular, and Evolutionary Biology 280 (2): 934–9. doi:10.1002/ar.a.20099. PMID 15372490.
^ Sharma G, Linden MD, Schultz DS, Inamdar KV (January 2009). "Cystic tumor of the atrioventricular node: an unexpected finding in an explanted heart". Cardiovascular Pathology : the Official Journal of the Society for Cardiovascular Pathology 19 (3): e75–8. doi:10.1016/j.carpath.2008.10.011. PMID 19144541.

External links

SUNY Figs 20:06-02 - "The conduction system of the heart."
thoraxlesson4 at The Anatomy Lesson by Wesley Norman (Georgetown University) (thoraxheartinternalner)
http://www.healthyheart.nhs.uk/heart_works/heart03.shtml

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. 心電図チュートリアル：伝導系の生理学 ecg tutorial physiology of the conduction system
2. 房室ブロックの原因 etiology of atrioventricular block
3. 心房細動における心拍数のコントロール：薬理療法 control of ventricular rate in atrial fibrillation pharmacologic therapy
4. 心房細動における心拍数のコントロール：非薬物療法 control of ventricular rate in atrial fibrillation nonpharmacologic therapy
5. 心房細動における心臓再同期療法 cardiac resynchronization therapy in atrial fibrillation

English Journal

Device Therapy for Acute Systolic Heart Failure and Atrial Fibrillation.

Carlson SK1, Doshi RN2.
Cardiac electrophysiology clinics.Card Electrophysiol Clin.2015 Sep;7(3):469-77. doi: 10.1016/j.ccep.2015.05.016. Epub 2015 Jun 26.
Patients with newly diagnosed cardiomyopathy require careful assessment of cause and initiation of treatment before the decision is made to implant an internal cardiac defibrillator. In patients with medicine-refractory atrial fibrillation and cardiomyopathy, atrioventricular node ablation and impla
PMID 26304527

Bradycardia: sinus and AV node dysfunction.

Pellegrini CN1, Scheinman MM.
Herzschrittmachertherapie & Elektrophysiologie.Herzschrittmacherther Elektrophysiol.2015 Aug 12. [Epub ahead of print]
The surface electrocardiogram (ECG) holds many clues with regard to the etiology of bradycardia and site of atrioventricular (AV) block. Bedside maneuvers may prove helpful in cases of 2:1 AV block or situations where the data is not all concordant. Wenckebach conduction may occur in any region of t
PMID 26264482

Wobble.

Asirvatham SJ1, Stevenson WG2.
Circulation. Arrhythmia and electrophysiology.Circ Arrhythm Electrophysiol.2015 Aug;8(4):985-7. doi: 10.1161/CIRCEP.115.002998.
PMID 26286308

Japanese Journal

Arrhythmia/Electrophysiology : Clinical and Electrophysiological Characteristics of Typical Atrioventricular Nodal Reentrant Tachycardia in the Elderly : Changing of Slow Pathway Location With Aging

Alihanoglu Yusuf I.,Yildiz Bekir S.,Kilic Dogu I. [他]
Circulation journal : official journal of the Japanese Circulation Society 79(5), 1031-1036, 2015-05
NAID 40020437062

Clinical and Electrophysiological Characteristics of Typical Atrioventricular Nodal Reentrant Tachycardia in the Elderly　– Changing of Slow Pathway Location With Aging –

, , , ,
Circulation Journal 79(5), 1031-1036, 2015
… Background:The aim of this study was to retrospectively evaluate the clinical and electrophysiological characteristics of elderly patients with typical atrioventricular nodal reentrant tachycardia (AVNRT), and to assess the acute safety and efficacy of slow-pathway radiofrequency (RF) ablation in this specific group of patients.Methods and Results:The present study retrospectively included a total of 1,290 patients receiving successful slow-pathway RF ablation for typical slow-fast AVNRT. …
NAID 130005066271

Clinical and Electrophysiological Characteristics of Typical Atrioventricular Nodal Reentrant Tachycardia in the Elderly:– Changing of Slow Pathway Location With Aging –

, , , ,
Circulation Journal advpub(0), 2015
… Background:The aim of this study was to retrospectively evaluate the clinical and electrophysiological characteristics of elderly patients with typical atrioventricular nodal reentrant tachycardia (AVNRT), and to assess the acute safety and efficacy of slow-pathway radiofrequency (RF) ablation in this specific group of patients.Methods and Results:The present study retrospectively included a total of 1,290 patients receiving successful slow-pathway RF ablation for typical slow-fast AVNRT. …
NAID 130004927210

Related Pictures

★リンクテーブル★

リンク元	「田原結節」「A-V node」
関連記事	「node」「atrioventricular」「nod」

「田原結節」

Atrioventricular node
	Isolated heart conduction system showing atrioventricular node
	Conduction system of the Heart
Latin	Nodus atrioventricularis
Artery	Atrioventricular nodal branch