Management of tachyarrhythmias: Out of Breath

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Author: Blake Briggs, MD

Objectives: approach to tachyarrhythmias, their EKG features, treatments, and complications

Stable vs Unstable

-the most important step. Determines treatment, disposition.


1-      Stable vs unstable?

2-      P waves present?

3-      Regular or irregular?

4-      QRS wide or narrow (<3 small boxes)?

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Sinus tachycardia is NOT included in this discussion today as it is considered an “appropriate” response to some pathology. One should address underlying causes (infection, trauma, PE, etc).

Today in a general nutshell:     Stable = meds first   Unstable = shock first

Heart rates >140 are generally considered to be pathologic as this is when cardiac output begins to decrease.

1)      Stable vs unstable: Assess ABC’s (protecting airway and verbalizing, breathing, BP >90)

2)      P waves? Initial step to determine if sinus rhythm or not. Rate?

a.      Must be upright and in every lead.

3)      Wide or narrow?

a.      Narrow = above the AV node (atrial origin)

b.      Wide = below the AV node (BBB, Purkinje system, ventricular myocytes)

4)      Regular or irregular?

a.      Regular = predictable rhythm.

b.      Irregular = rhythm is not predictable due to electricity coming in variable responses from the SA node.


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