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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/01/23 21:42:00」(JST)

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Normal electrical conduction system of the heart (Schematic). All myocardial segments are excited almost simultaneously (purple staining).

1. Sinoatrial node

2. Atrioventricular node.

Conduction in RBBB (Schematic): With a blockage in the right bundle branch (red), the left ventricle is excited in time (purple), while the excitation of the right ventricle takes a detour via the left bundle branch (blue arrows).

A right bundle branch block (RBBB) is a defect in the heart's electrical conduction system.^[1]

During a right bundle branch block, the right ventricle is not directly activated by impulses travelling through the right bundle branch. The left ventricle however, is still normally activated by the left bundle branch. These impulses are then able to travel through the myocardium of the left ventricle to the right ventricle and depolarise the right ventricle this way. As conduction through the myocardium is slower than conduction through the Bundle of His-Purkinje fibres, the QRS complex is seen to be widened. The QRS complex often shows an extra deflection which reflects the rapid depolarisation of the left ventricle followed by the slower depolarisation of the right ventricle.

RBBB often has pathological cause, although it is mostly seen in extremely fit and healthy individuals.^[2]

Diagnosis

The criteria to diagnose a right bundle branch block on the electrocardiogram:

The heart rhythm must originate above the ventricles (i.e. sinoatrial node, atria or atrioventricular node) to activate the conduction system at the correct point.
The QRS duration must be more than 100 ms (incomplete block) or more than 120 ms (complete block)^[3]
There should be a terminal R wave in lead V1 (e.g. R, rR', rsR', rSR' or qR)
There should be a slurred S wave in leads I and V6.

The T wave should be deflected opposite the terminal deflection of the QRS complex. This is known as appropriate T wave discordance with bundle branch block. A concordant T wave may suggest ischemia or myocardial infarction.

A mnemonic to distinguish between ECG signatures of Left bundle branch block (LBBB) and right, is WiLLiaM MaRRoW; i.e., with LBBB, there is a W in lead V1 and an M in lead V6, whereas, with RBBB, there is an M in V1 and a W in V6.

Causes

An atrial septal defect is one possible cause of a right bundle branch block.^[4] In addition, a right bundle branch block may also result from Brugada syndrome, right ventricular hypertrophy, pulmonary embolism, ischaemic heart disease, rheumatic heart disease, myocarditis or cardiomyopathy.

Epidemiology

Prevalence of RBBB increases with age.

Gallery

RBBB with associated first degree AV block
RBBB with associated tachycardia
RBBB

References

^ "Conduction Blocks 2006 KCUMB". Retrieved 2009-01-20.
^ Da Costa D, Brady WJ, Edhouse J (March 2002). "Bradycardias and atrioventricular conduction block". BMJ 324 (7336): 535–8. doi:10.1136/bmj.324.7336.535. PMC 1122450. PMID 11872557.
^ "Lesson VI - ECG Conduction Abnormalities". Retrieved 2009-01-07.
^ Goldman, Lee (2011). Goldman's Cecil Medicine (24th ed ed.). Philadelphia: Elsevier Saunders. pp. 400–401. ISBN 1437727883.

UpToDate Contents

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1. 右脚ブロック right bundle branch block
2. 心電図チュートリアル：心室内ブロック ecg tutorial intraventricular block
3. ブルガダ症候群および突然の心停止 brugada syndrome
4. 脚ブロックまたはペーシング調律存在下での心筋梗塞の心電図による診断 electrocardiographic diagnosis of myocardial infarction in the presence of bundle branch block or a paced rhythm
5. 経カテーテル的大動脈弁置換術 transcatheter aortic valve replacement

English Journal

Possible causes of the gradient decrease in the right ventricular outflow tract in biventricular hypertrophic cardiomyopathy.

Kırat T1, Köse N2, Altun İ2, Akın F2, Soylu MÖ2.
International journal of cardiology.Int J Cardiol.2016 Apr 15;209:349. doi: 10.1016/j.ijcard.2015.10.055. Epub 2015 Oct 8.
PMID 26476969

Where is the exact origin of narrow premature ventricular contractions manifesting qR in inferior wall leads?

Zheng C1, Li J1, Lin JX1, Wang LP1, Lin JF2.
BMC cardiovascular disorders.BMC Cardiovasc Disord.2016 Apr 4;16(1):64. doi: 10.1186/s12872-016-0240-4.
BACKGROUND: In recent years, radiofrequency catheter ablation(RFCA) has been established as an effective therapy for idiopathic premature ventricular contractions (PVCs), however, its effect on the narrow PVCs (QRS duration < 130 msec) with qR pattern in inferior leads, may not been fully co
PMID 27044385

Exercise left ventricular ejection fraction predicts events in right bundle branch block.

Peteiro J1, Bouzas-Mosquera A1, Broullón J2, Yañez J1, Martinez D1, Vazquez JM1.
Scandinavian cardiovascular journal : SCJ.Scand Cardiovasc J.2016 Apr;50(2):108-13. doi: 10.3109/14017431.2015.1118529. Epub 2015 Dec 4.
Objective Interpretation of the electrocardiogram (ECG) during exercise is not easy in patients with right bundle branch block (RBBB). Also, the value of exercise echocardiography (ExE) for predicting outcome in them has not been addressed. We sought to assess its prognostic value in patients with R
PMID 26634337

Japanese Journal

心房中隔欠損症術後, 心室性期外収縮に伴う心不全を発症し, カテーテルアブレーションにより改善した幼児例

心臓 46(SUPPL.3), S3_253-S3_257, 2014
NAID 130005103989

切除不能な心臓腫瘍に関連した心室頻拍を開胸下凍結凝固により抑制しえたGorlin症候群の1例—病理学的見地も踏まえて—

心臓 46(SUPPL.3), S3_258-S3_263, 2014
NAID 130005103980

心房中隔欠損における心電図所見の検討：下方誘導のnotch は有用か

日本小児循環器学会雑誌 29(6), 322-327, 2013
NAID 130003388654

Related Pictures

★リンクテーブル★

リンク元	「II音」「右脚ブロック」「widened splitting」「right bundle-branch block」
拡張検索	「CRBBB」

「II音」

Right bundle branch block
	ECG characteristics of a typical RBBB showing wide QRS complexes with a terminal R wave in lead V1 and slurred S wave in lead V6.
Classification and external resources
ICD-10	I45.1
ICD-9	426.4
DiseasesDB	11620
eMedicine	ped/2500

　　[★]

英: second heart sounds, S2
関: 心音

まとめ

II音亢進	II_A	高血圧	AR	動脈硬化
II音亢進	II_P	肺高血圧	PR	MS
II音減弱	II_A	低血圧	AS
II音減弱	II_P		PS

II音増大

MSとASとでは、同じstenosisでも心音の大きさに関与の仕方が違うんですね。

(体循環)高血圧症、肺動脈高血圧症。(PHD.35)

拡張期における大動脈圧、肺動脈圧が高い　→　弁に衝突する血液の流速が早い　→　弁の閉鎖音が大きい

動脈硬化の強いとき

大動脈弁が閉じるとき、拡張期早期 back pressureが高い？

大動脈弁閉鎖不全症 AR

拡張期に大動脈弁を挟んだback pressureが高いから？

肺動脈弁閉鎖不全症 PR

心室中隔欠損症

右室へのvolume load。PHで顕著

II音減弱

大動脈弁狭窄症(AS)、肺動脈弁狭窄症(PS)。(PHD.35)

駆出できる血液量がへるから？

分裂音

呼吸性分裂

PHD.33-35

生理的状態では、

		横隔膜の相対的位置	II音
呼気	expiration	￣	｜	single sound
吸気	inspiration	＿	｜　｜	splitting sound

(1)吸気時には、肺の血管抵抗性が低下　→　拡張期におけるP弁へのback pressureは呼気時と比べ比較的低下する　→P弁の開放時間が延長
(2)吸気時には、肺静脈が拡張　→　左房・左室への血液還流量が減少　→　左室を充満する血液量減少　→　一回拍出量減少　→　駆出時間の短縮　→　A弁の開放時間が短縮

心音#まとめ

widened splitting

right bundle branch block(RBBB), pulmonic stenosis(PS)

IIAが早まる：MR, VSD

IIPが遅れる：RBBB, PS, pulmonary hypertension

「右脚ブロック」

　　[★]

英: right bundle branch block right bundle-branch block RBBB
関: 左脚ブロック、束枝ブロック、脚ブロック

脚ブロックと心音、電気軸との関係

		心機能の予後	心音	電気軸	原因
右脚ブロック		良好	病的分裂(IIP遅延)	不変(YN.C-50)/右軸偏位
左脚ブロック		良好ではない	奇異性分裂(IIA遅延)		虚血性心疾患、高血圧、心筋症、心不全、左室肥大
	左脚前枝ブロック			左軸偏位
	左脚後枝ブロック			右軸偏位

心電図

V1でrSR' ：R'は右室の興奮を表し幅広く高い波。

「widened splitting」

　　[★]

関: II音

概要

通常の心音はS1→A2→P2　だけど、widened splittingではS1→P2→→→A2となる。

原因

right bundle branch block(RBBB), pulmonic stenosis(PS)

IIPが遅れる：RBBB, PS, pulmonary hypertension

奇異性分裂の逆パターンと覚える！！

IIAが早まる：MR, VSD(YN.C-109)

僧帽弁閉鎖不全症 MR：左心室収縮駆出された血液は大動脈以外に左心房にも流れ込む。大動脈に駆出する血液量が減少するため、大動脈弁は早期閉鎖する。~~A弁を挟んだ圧較差を考えると、僧帽弁閉鎖不全症の場合、心房からの逆流により心室圧が早く上昇すると考えればよい。~~

心室中隔欠損症 VSD：欠損孔を通じて右心室に流れ込むために、大動脈に駆出する血液量が減少するため大動脈弁は早期閉鎖する。

「right bundle-branch block」

　　[★] 右脚ブロック RBBB

「CRBBB」

　　[★]

同: complete right bundle branch block, 完全右脚ブロック

[urlConduction_Blocks_2006_KCUMB-1] "Conduction Blocks 2006 KCUMB". Retrieved 2009-01-20.

[2] Da Costa D, Brady WJ, Edhouse J (March 2002). "Bradycardias and atrioventricular conduction block". BMJ 324 (7336): 535–8. doi:10.1136/bmj.324.7336.535. PMC 1122450. PMID 11872557.

[urlLesson_VI_-_ECG_Conduction_Abnormalities-3] "Lesson VI - ECG Conduction Abnormalities". Retrieved 2009-01-07.

[Cecil-4] Goldman, Lee (2011). Goldman's Cecil Medicine (24th ed ed.). Philadelphia: Elsevier Saunders. pp. 400–401. ISBN 1437727883.

匿名

検索

案内

案内

RBBB