EKG FeaturesRate: Normal to slow
Rhythm: Irregular due to pause
P Wave: Normal
PR Interval: Normal (0.12-0.20 sec)
QRS: Normal (0.06-0.10 sec)
Sudden absence of electrical activity initiated by the SA node. This results in a pause in the electrical activity seen on the tracing. The rhythm typically will demonstrate constant R to R intervals prior to and following the pause.
Sinus arrest is a pause in the generation of electrical impulses by the SA node. The sinus arrest pause is usually followed by a new sinus node beat or by an AV node escape beat. If no pacemaker begins activity, then the condition becomes cardiac arrest. If an ectopic site (e.g. AV junction or ventricles) takes over, the beat will likely be slower. Refer to sinoatrial block for information on a similar EKG.
Sinus Arrest Example
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