Bradycardia: Difference between revisions

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To understand the pathophysiologic basis of most conduction disorders or disorders of impulse formation it is important to understand the physiology of cardiac conduction and mechanisms of arrhythmia as detailed in the general cardiac arrhythmia section [Link].  
To understand the pathophysiologic basis of most conduction disorders or disorders of impulse formation it is important to understand the physiology of cardiac conduction and mechanisms of arrhythmia as detailed in the general cardiac arrhythmia section [Link].  
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Abbreviations
AV: atrioventricular
bpm: beats per minute
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=Sinus Node Dysfunction=
=Sinus Node Dysfunction=
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=AV-Block=
=AV-Block=
==First Degree AV Block==
==First Degree AV Block==
Technically a AV-delay and not a AV block, 1st degree AV block is defined as a prolonged interval between atrial and ventricular activation (>200ms). This delay results from disease in the AV-node or His-Purkinje system. An AV block is not the cause of bradycardia, because every atrial impulse results in conduction to the ventricles.
==Second Degree AV Block==
==Second Degree AV Block==
===Mobitz I (Wenkebach)===
===Mobitz I (Wenkebach)===
The Mobitz type I block is characterized by a progressively increased P-Q interval until atrial activation is blocked in the AV-node. Thereafter conduction is restored and this cycle repeats itself. Usually Mobitz type II block is located at a the atrioventricular node and rarely deteriorates to a more severe conduction block.
===Mobitz II===
===Mobitz II===
==Third Degree AV Block==
==Third Degree AV Block==


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