WordNet

an implanted electronic device that takes over the function of the natural cardiac pacemaker (同)artificial_pacemaker
a specialized bit of heart tissue that controls the heartbeat (同)cardiac_pacemaker, sinoatrial_node, SA_node
travelling about without any clear destination; "she followed him in his wanderings and looked after him" (同)roving, vagabondage

PrepTutorEJDIC

(また《おもに米》『pacesetter』)ペースメーカー(レースで先頭に立って速度の調整役となる走者) / 脈拍調整器(心臓病の治療器)
歩き回る,さまよう / 曲がりくねる / 放浪,さすらい / うわごと

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/09/26 02:32:22」(JST)

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A wandering atrial pacemaker, (WAP), is an atrial arrhythmia that occurs when the natural cardiac pacemaker site shifts between the sinoatrial node (SA node), the atria, and/or the atrioventricular node (AV node). This shifting of the pacemaker from the SA node to adjacent tissues is identifiable on ECG Lead II by morphological changes in the P-wave; sinus beats have smooth upright P waves, while atrial beats have flattened, notched, or diphasic P-waves. It is often seen in the very young, very old, in athletes and rarely causes symptoms or requires treatment^{[citation needed]}.

Cause

Wandering pacemaker is usually caused by varying vagal tone. With increased vagal tone the SA Node slows, allowing a pacemaker in the atria or AV Nodal area, which may briefly become slightly faster. After vagal tone decreases, the SA Node assumes its natural pace.

A wandering atrial pacemaker, also termed multifocal atrial rhythm, is present when there are three or more ectopic foci within the atrial myocardium that serve as the dominant pacemaker (waveform 5). Since they discharge in random fashion, the pacemaker location is continuously shifting and may be located anywhere in the atrial myocardium. As a result, there is a changing vector of atrial activation that causes a changing P wave morphology and PR interval duration. A dominant P wave (sinus or atrial) cannot be identified. The rate is less than 100 beats per minute.

The RR intervals have variable cycle lengths since the ectopic foci exhibit differences in automaticity and rates of impulse generation. The rhythm is therefore irregularly irregular, and it can be confused with atrial fibrillation. However, in contrast to atrial fibrillation, distinct P waves are present. Sinus arrhythmia may also be irregularly irregular; however, one P wave morphology and PR interval are seen in this situation. This arrhythmia may also be confused with sinus rhythm with multifocal premature atrial contractions, although in this situation a dominant sinus P wave can be identified and there are periods of RR interval regularity. Ventricular conduction is normal with wandering pacemaker, and thus the QRS complex is normal.

External links

Cleveland Clinic Atrial Fibrillation Management
CEUFast ECG Interpretation Course
RnCeus Health Interactive
RN.ORG Nursing Resources

UpToDate Contents

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1. 心電図チュートリアル：心房性および房室結節性（上室性）不整脈 ecg tutorial atrial and atrioventricular nodal supraventricular arrhythmias
2. 多源性心房性頻拍 multifocal atrial tachycardia
3. 洞房結節の一時停止、停止、および進出ブロック sinoatrial nodal pause arrest and exit block
4. 心房細動の心電図 the electrocardiogram in atrial fibrillation
5. アスリートにおける不整脈 arrhythmia in athletes

English Journal

Cardioautonomic instability following a sports-related concussion in a 20-year-old male.

La Fountaine MF1, Toda M2, Testa A2, Bauman WA3.
International journal of cardiology.Int J Cardiol.2014 Apr 1;172(3):e511-2. doi: 10.1016/j.ijcard.2014.01.095. Epub 2014 Jan 24.
PMID 24491870

Hemodialysis treatment of monomorphic ventricular tachycardia associated with chronic lithium toxicity.

Bosak AR1, Graeme KA, Evans MD.
Journal of medical toxicology : official journal of the American College of Medical Toxicology.J Med Toxicol.2014 Sep;10(3):303-6. doi: 10.1007/s13181-013-0366-z.
INTRODUCTION: A patient with chronic lithium toxicity developed a life-threatening ventricular arrhythmia that resolved during removal of lithium by hemodialysis. Chronic lithium toxicity commonly results from diminished elimination and can produce neurotoxicity. Cardiovascular complications have be
PMID 24381125

Japanese Journal

乳幼児の潜水・水泳における心拍反応と不整脈

林貢一郎,佐々木純一,目崎登
体力科學 50(5), 603-612, 2001-10-01
… Another arrhythmias observed was atrioventricular junctional rhythm(AVJR, 1 subject), atrioventricular junctional escaped beat(AVJES, 3 subjects) and wandering pacemaker(1 subject). …
NAID 110001919063

二酸化窒素の急性暴露によるラット心機能の変化

局博一 [他],鈴木明,市瀬孝道,嵯峨井勝,織田肇,久保田憲太郎
日本衛生学雑誌 36(2), 550-559, 1981
… Arrhythmias including atrioventricular blocks and premature systoles, and wandering pacemaker were observed during exposure to 20ppm and 40ppm. …
NAID 130001000871