Ectopic Complexes: Difference between revisions

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m (New page: =Ectopic beats= The pacemakercells in the sinusnode are not the only cells in the heart that can depolarize spontaneously. Actually all cardiomyoctyes have this capacity. The only reason w...)
 
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===Premature atrial complex / atrial extrasystole===
===Premature atrial complex / atrial extrasystole===
[[Image:Rhythm_premature.png|thumb| A premature atrial complex (PAC). (In this example the atrial p-wave is difficult to discern).]]
{{: Premature Atrial Complexes}}
[[Image:Bes.png|thumb| A premature atrial complex (PAC) with evident negative p-wave]]
Premature atrial complexes origin from an ectopic pacing region in the atria. The result is a p-wave with often a different morphology as the preceding ones.
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===AV-nodal complexes===
===AV-nodal complexes===
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===Ventricular premature beat (VPB) / Ventricular extrasystole (VES)===
===Ventricular premature beat (VPB) / Ventricular extrasystole (VES)===
[[Image:Rhythm_ventricular_premature.png|thumb| The arrow indicates a ventricular extrasystole (VES).]]
{{: Ventricular Premature beats}}
A VPB is an ectopic beat that origins from the ventricles. VPBs are hardly conducted by the specialised conduction system and therefore are broad. The QRS width is at least > 0.12 seconds, but often very broad at around 0.16-0.20 seconds.
 
Causes: e.g. ischemia, hypoxia, old scar tissue, idiopathic. 50% of healthy men have sporadic VPBs.
The origin of the VPB can be derived from its form. A LBTB-configured VPB originates in the right ventricle. A RBTB-configured VPB comes from the left ventricle. The QRS duration of a VPB is > 0.12 seconds and can be as wide as 0.16-0.20 seconds.
 
A sequence of three or more extrasystoles is called a [[#ventricular tachycardia|non-sustained ventricular tachycardia]].
 
If more than one VPB is present on the ECG, they can be:
*'''monomorphic''': all VPBs have the same configuration and thus have a mutual focus of origin.
*'''multiformic''': the complexes have different configurations.
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===Bigemini===
===Bigemini===