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| | MCOMSDOCTORS NETWORK - ECG SVT |
 | | Most commonly, there is 2:1 conduction between the atrium and the ventricle; however, there may be 4:1 or 6:1 conduction when there is conduction delay or block within the atrioventricular node such as with drugs or enhanced vagal tone. | | | The atrial rate in atrial flutter is generally 260 to 320 when no cardiac drug therapy is being administered. | | | However, when this occurs, it is often due to dual atrioventricular nodal pathways and two levels of nodal blockade. |
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http://mcomsdoctors.8m.com/ecgsvt.html
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| | THE MERCK MANUAL, Sec. 16, Ch. 205, Arrhythmias |
| | Carotid sinus massage will slow or block atrioventricular nodal conduction, exposing the underlying atrial arrhythmia and suggesting that the atrioventricular node is not an integral part of the arrhythmia circuit. | | | The mechanism may be that drugs that block atrioventricular nodal conduction force conduction over the accessory pathway and reduce retrograde concealed penetration of the accessory pathway, thereby further enhancing or releasing accessory pathway conduction capacity. | | | Digoxin is contraindicated in all other circumstances because it may shorten atrial and accessory pathway refractory periods and encourage development of VF. |
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http://www.merck.com/mrkshared/mmanual/section16/chapter205/205g.jsp
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| | Catheter ablation for cardiac arrhythmias -- Peters 321 (7263): 716 -- BMJ |
| | Catheter ablation of accessory pathways, atrioventricular nodal reentrant tachycardia, and the atrioventricular junction: final results of a prospective, multicenter clinical trial. | | | There are well developed techniques using catheter ablation that can reliably cure arrhythmias such as atrioventricular junctional | | | Catheter ablation of accessory atrioventricular pathways (Wolff-Parkinson-White syndrome) by radiofrequency current. |
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http://www.bmj.com/cgi/content/full/321/7263/716
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| | Bradycardia |
| | Programmed stimulation test can be used to assess refractory periods and responses to changes in atrial rate. | | | When bradycardia occurs only in specific situations, patient education and prevention strategies should be tried first. | | | Wide QRS escape rhythms at slower rates imply that the block is located in the His-Purkinje system. |
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http://enotes.tripod.com/bradycardia.htm
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| | Gray's Anatomy - The Heart - Yahoo! Reference |
| | The deep layers are three in number; they arise in the papillary muscles of one ventricle and, curving in an S-shaped manner, turn in at the longitudinal sulcus and end in the papillary muscles of the other ventricle. | | | The nerves, although not concerned in originating the contractions of the heart muscle, play an important role in regulating their force and frequency in order to subserve the physiological needs of the organism. | | | The more embryonic the muscle the better is it able to initiate and propagate the contraction wave; this explains why the normal systole of the heart starts at the entrance of the veins, for there the muscle is most embryonic in nature. |
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http://messenger.yahooligans.com/reference/gray/138.html
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| | eMedicine - Supraventricular Tachycardia, Atrioventricular Node Reentry : Article by Robert Hamilton, MD |
| | Medicine is a constantly changing science and not all therapies are clearly established. | | | The fast pathway is identified by its short conduction time and long effective refractory period (ERP), whereas the slow pathway has longer conduction time and an ERP that typically is relatively short compared to fast pathway ERP. | | | Ideally, as with most tachycardias in children, transfer should take place after successful conversion has been achieved. |
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http://www.emedicine.com/ped/topic2535.htm
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| | eMedicine - Atrioventricular Block : Article by Wojciech Zareba, MD, PhD, FACC |
| | Patients with corrected transposition of the great vessels have anterior displacement of the AV node and are prone to develop complete heart block during right heart catheterization or surgical manipulation. | | | Strasberg B, Amat-Y-Leon F, Dhingra RC: Natural history of chronic second-degree atrioventricular nodal block. | | | The latter usually is observed in more advanced conduction disturbances such as Mobitz II AV block. |
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http://www.emedicine.com/med/topic189.htm
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| | Conduction System |
| | These pathways curve through the atrial walls and terminate in the atrioventricular bundle (refer to anatomy of conduction system). | | | These pathways also conduct the impulse at a faster rate. | | | The ends of the sinoatrial node fibers fuse with the surrounding atrial muscle fibers, and action potentials originating in the sinus node travel outward into these fibers. |
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http://oak.cats.ohiou.edu/~jr888793/conduction.html
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| | Atrioventricular node - Medical Dictionary definitions of popular medical terms |
| | This quick response is important during exercise when the heart has to increase its beating speed to keep up with the body's increased demand for oxygen. | | | Atrioventricular node - Medical Dictionary definitions of popular medical terms | | | This stunningly designed system generates electrical impulses and conducts them throughout the muscle of the heart, stimulating the heart to contract and pump blood. |
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http://www.medterms.com/script/main/art.asp?articlekey=2387
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| | The Sun Herald 04/22/2004 WPW rarely fatal in modern era |
| | A: In WPW an extra or accessory pathway exists, one of these, called a Kent bundle in which conduction occurs rapidly from the atria to the ventricles, bypassing the normal organized pathway allowing the development of rapid heart arrhythmias or rhythm that can conduct at high speeds. | | | The left ventricle contracts and oxygenated blood is sent to the rest of the body. | | | Electrical conduction in the heart is initiated by special cells in an area of the upper right atrium called the sino-atrial node (SA) node. |
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http://www.sunherald.com/mld/thesunherald/living/8488934.htm
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| | atrioventricular node (av node) |
| | Aging changes in the human atrioventricular node, bundle, and bundle branches. | | | Differential developmental effects of acute hypoxia on the rabbit atrioventricular conduction axis. |
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http://www.arclab.org/node_pages/348.html
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| | MedlinePlus Medical Encyclopedia: Paroxysmal supraventricular tachycardia (PSVT) |
| | The signal is conducted through the atria (the upper heart chambers) and stimulates the atria to contract. | | | Paroxysmal supraventricular tachycardia (PSVT) can be initiated in the SA node; in the atria or the atrial conduction pathways; or in the AV node. | | | The electrical signal then passes through the atrioventricular node (AV node), and travels through the ventricles (the larger, lower chambers), stimulating them to contract. |
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http://www.nlm.nih.gov/medlineplus/ency/article/000183.htm
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| | Virtual Cath Lab |
| | atrioventricular node, or AV node, is made up of another cluster of specialized cardiac conduction system cells. | | | The AV node forms a pathway for impulse conduction that bridges between the atria and ventricles. | | | This causes a delay in the transmission of the depolarization wave to the ventricles. |
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http://user.gru.net/clawrence/vccl/chpt2/ATRIO.htm
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| | The Bristol Press - News - 12/25/2004 - Bit of frostbite can help heart |
| | The heart works fine as long as the muscle cells receive the right signals from a bundle of nerves over the right atrium called the sinus node. | | | However, abnormal heart cells sometimes issue their own signals or can loop back on the sinus node. | | | An electrical conduction circuit of nerves opens and closes valves and constricts the four chambers in precisely the right order about 70 times a minute in a person at rest. |
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http://www.zwire.com/site/news.cfm?newsid=13624483&BRD=1643&PAG=461&dept_id=10486&rfi=6
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| | Encyclopedia4U - Walter Karl Koch - Encyclopedia Article |
| | Walter Karl Koch was a German surgeon ( Dortmund, Germany, May 3 1880 - ? | | | After being named a professor in 1922, he worked as head of department at the Krankenhaus Westend. | | | ), best known for the Tawara's node, the atrioventricular node which is the beginning of his bundle about the auricular-ventricular. |
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http://www.encyclopedia4u.com/w/walter-karl-koch.html
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| | Exam |
| | Produced by closure of atrioventricular valves (AV valves) | | | Match the letters of the following functions/descriptions with their "Terms": | | | Produced by closure of semilunar valves (SL valves) |
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http://www.linkpublishing.com/cgi-bin/ie.cgi?exam=chap27p.exm
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| | Atrioventricular Block |
| | This is one page of 28 in this chapter, 294 in this book, and 4534 in the Family Practice Notebook. | | | Impaired conduction in Atria, AV node or His-Purkinje |
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http://www.fpnotebook.com/CV11.htm
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| | Heart and Stroke Encyclopedia |
| | A-V Block or AV Block, First Degree — see Heart Block | | | A-V Node or AV Node (Atrioventricular Node) — see Heart Block ; Radiofrequency Ablation | | | Atrioventricular Canal Defect (A-V or AV Canal Defect) — see Congenital Cardiovascular Defects |
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http://www.americanheart.org/presenter.jhtml?identifier=10000056
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