WordNet

a three-dimensional shape with six square or rectangular sides (同)cube
(computer science) a sector or group of sectors that function as the smallest data unit permitted; "since blocks are often defined as a single sector, the terms `block and `sector are sometimes used interchangeably"
support, secure, or raise with a block; "block a plate for printing"; "block the wheels of a car"
a solid piece of something (usually having flat rectangular sides); "the pyramids were built with large stone blocks"
housing in a large building that is divided into separate units; "there is a block of classrooms in the west wing"
a rectangular area in a city surrounded by streets and usually containing several buildings; "he lives in the next block" (同)city block
an inability to remember or think of something you normally can do; often caused by emotional tension; "I knew his name perfectly well but I had a temporary block" (同)mental_block
a number or quantity of related things dealt with as a unit; "he reserved a large block of seats"; "he held a large block of the companys stock"
interrupt the normal function of by means of anesthesia; "block a nerve"; "block a muscle"
run on a block system; "block trains"
shape by using a block; "Block a hat"; "block a garment"
shape into a block or blocks; "block the graphs so one can see the results clearly"
stamp or emboss a title or design on a book with a block; "block the book cover"
completely obstructed or closed off; "the storm was responsible for many blocked roads and bridges"; "the drain was plugged" (同)plugged
closed to traffic; "the repaving results in many blocked streets" (同)out of use
a group of countries in special alliance (同)axis
the transmission of heat or electricity or sound (同)conductivity
the act of obstructing or deflecting someones movements (同)block

PrepTutorEJDIC

(木・石などの,通例平らな面のある)『かたまり』 / 《米》(四団を街路に囲まれた)『区画』,街区 / 街区の1辺の距離(一般に40メートル前後) / 《英》ブロック(アパート・事務所・商店などに区切られている大きな建物) / 『妨害物』,障害物(obstacle);(障害によって生じた)停滞,渋滞 / 台木,台(まないた・肉切り台・まき割り台・せり売り台・帽子の木型など);《the~》炭頭台 / (特にアメリカンフットボールで)ブロック(相手の選手の突進を阻止する) / 滑車(pulley) / (座席券・株券などの)一組《+『of』+『名』》 / 〈通路など〉'を'『ふさぐ』,〈通行・進行など〉'を'妨げる / 〈帽子など〉の型取りをする / (特にアメリカンフットボールで)〈相手選手の突進〉'を'ブロックする;(ボクシングで)〈相手のパンチ〉'を'ブロックする
ブロック,圏(地理・共通の利害・政治・経済上の目的などのために団結した団体・国家などの結合体)
(熱・電気の)伝導;(液体を)管などで導くこと

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/07/27 09:38:15」(JST)

wiki en

A heart block is a disease in the electrical system of the heart. This is opposed to coronary artery disease, which is disease of the blood vessels of the heart. While coronary artery disease can cause angina (chest pain) or myocardial infarction (heart attack), heart block can cause lightheadedness, syncope (fainting), and palpitations.

Types

Sinus rhythm with acute inferior infarction complicated by Type I A-V block manifest in the form of 5:4 Wenckebach periods; R-P/P-R reciprocity.

Sinus rhythm(rate = 100/min) with 3:2 and 2:1 Type II A-V block;RBBB

Sinus tachycardia with complete A-V block and resulting junctional escape

A heart block can be a blockage at any level of the electrical conduction system of the heart (shown in the diagram on the right).

Blocks that occur within the sinoatrial node (SA node) are described as SA nodal blocks.
Blocks that occur within the atrioventricular node (AV node) are described as AV nodal blocks.
Blocks that occur below the AV node are known as infra-Hisian blocks (named after the bundle of His).
Blocks that occur within the left or right bundle branches are known as bundle branch blocks.
Blocks that occur within the fascicles of the left bundle branch are known as hemiblocks.

Clinically speaking, most of the important heart blocks are AV nodal blocks and infra-Hisian blocks.

SA nodal blocks

The SA nodal blocks rarely give symptoms. This is because if an individual had complete block at this level of the conduction system (which is uncommon), the secondary pacemaker of the heart would be at the AV node, which would fire at 40 to 60 beats a minute, which is enough to retain consciousness in the resting state.

Types of SA nodal blocks include:

SA node Wenckebach (Mobitz I)^[1]
SA node Mobitz II
SA node exit block

In addition to the above blocks, the SA node can be suppressed by any other arrhythmia that reaches it. This includes retrograde conduction from the ventricles, ectopic atrial beats, atrial fibrillation, and atrial flutter.

The difference between SA node block and SA node suppression is that in SA node block an electrical impulse is generated by the SA node that doesn't make the atria contract. In SA node suppression, on the other hand, the SA node doesn't generate an electrical impulse because it is reset by the electrical impulse that enters the SA node.

AV nodal blocks

There are three basic types of AV nodal block:

First degree AV block
Second degree AV block
- Type I second degree AV block (Mobitz I) (also known as Wenckebach block)
- Type 2 second degree AV block (Mobitz II) - usually but not always below the AV node and therefore infraHisian - see below^{[citation needed]}
Third degree AV block (Complete heart block)

Infra-Hisian block

Infrahisian block describes block of the distal conduction system. Types of infrahisian block include:

Type 2 second degree heart block (Mobitz II)^{[dubious – discuss]}
Left bundle branch block
- Left anterior fascicular block
- Left posterior fascicular block
Right bundle branch block

Of these types of infrahisian block, Mobitz II heart block is considered most important because of the possible progression to complete heart block.

References

^ Valentin Fuster, R. Wayne Alexander, Robert A. O'Rourke, Robert Roberts et al. (November 2000). Hurst's The Heart, 10th Edition. McGraw-Hill Professional Publishing. Figure 24–60b. ISBN 0-07-135695-9.

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. 神経伝導検査の概要 overview of nerve conduction studies
2. 心電図チュートリアル：心室内ブロック ecg tutorial intraventricular block
3. 第2度房室ブロック：モビッツII型 second degree atrioventricular block mobitz type ii
4. 房室ブロックの原因 etiology of atrioventricular block
5. 心電図チュートリアル：房室ブロック ecg tutorial atrioventricular block

English Journal

A novel NKX2-5 loss-of-function mutation predisposes to familial dilated cardiomyopathy and arrhythmias.

Yuan F1, Qiu XB2, Li RG2, Qu XK2, Wang J3, Xu YJ2, Liu X2, Fang WY2, Yang YQ2, Liao DN1.
International journal of molecular medicine.Int J Mol Med.2015 Feb;35(2):478-86. doi: 10.3892/ijmm.2014.2029. Epub 2014 Dec 9.
Dilated cardiomyopathy (DCM) is the most prevalent type of primary myocardial disease, which is the third most common cause of heart failure and the most frequent reason for heart transplantation. Aggregating evidence demonstrates that genetic risk factors are involved in the pathogenesis of idiopat
PMID 25503402

A Novel Apolipoprotein C-II Mimetic Peptide That Activates Lipoprotein Lipase and Decreases Serum Triglycerides in Apolipoprotein E-Knockout Mice.

Amar MJ1, Sakurai T2, Sakurai-Ikuta A2, Sviridov D2, Freeman L2, Ahsan L2, Remaley AT2.
The Journal of pharmacology and experimental therapeutics.J Pharmacol Exp Ther.2015 Feb;352(2):227-35. doi: 10.1124/jpet.114.220418. Epub 2014 Nov 13.
Apolipoprotein A-I (apoA-I) mimetic peptides are currently being developed as possible new agents for the treatment of cardiovascular disease based on their ability to promote cholesterol efflux and their other beneficial antiatherogenic properties. Many of these peptides, however, have been reporte
PMID 25395590

Effectiveness of implantation of a subcutaneous implantable cardioverter-defibrillator in a patient with complete heart block and a pacemaker.

Porterfield C1, DiMarco JP1, Mason PK2.
The American journal of cardiology.Am J Cardiol.2015 Jan 15;115(2):276-8. doi: 10.1016/j.amjcard.2014.10.036. Epub 2014 Oct 31.
The subcutaneous implantable cardioverter-defibrillator (S-ICD) represents an important alternative to traditional ICD therapy. The major limitation of this technology is the inability to provide pacing. Here, we present a case of a patient with complete heart block and a pacemaker who underwent pla
PMID 25465940

Japanese Journal

Unique preferential conduction within the isolated septal substrate in a patient with ventricular tachycardia complicated with non-ischemic dilated cardiomyopathy

Watanabe Masaya,Yokoshiki Hisashi,Mitsuyama Hirofumi,Mizukami Kazuya,Tsutsui Hiroyuki
Journal of electrocardiology 46(6), 682-685, 2013-11
… Pacemapping exhibited either left, identical to clinical VT, or right bundle branch block like wide QRS morphology. … Difference in the morphology of pacemapping was dependent on whether or not the pacing stimulus could propagate directly into the right ventricle due to the possible intramural conduction disturbance. …
NAID 120005365911

多巣性運動ニューロパチー(MMN)の疫学・病態と治療 (特集免疫性神経疾患)

松井尚子,宮城愛,梶龍兒
日本臨床 71(5), 861-864, 2013-05
NAID 40019678700

Multifocal Conduction Block in a Patient with Sarcoid Neuropathy: Successful Treatment with Intravenous Immunoglobulin

Kono Yu,Omoto Shusaku,Sengoku Renpei,Yaguchi Hiroshi,Sonoo Masahiro,Inoue Kiyoharu,Mochio Soichiro
Internal Medicine 52(9), 999-1002, 2013
… Nerve conduction studies showed multifocal conduction blocks in several nerves. … however, intravenous immunoglobulin (IVIG) therapy rapidly and repeatedly improved the patient's neurologic symptoms with a resolution of the conduction blocks. … Multifocal conduction blocks are not frequently reported in patients with sarcoid neuropathy, but they may respond to early treatment with IVIG. …
NAID 130003366009

Related Pictures

★リンクテーブル★

リンク元	「刺激伝導障害」「伝導障害」「conduction defect」「conduction disorder」「伝導ブロック」
拡張検索	「multifocal demyelinating neuropathy with persistent conduction block」「bidirectional conduction block」
関連記事	「block」「conduction」