Rhythm InterpretationQuestion 18 of 100

A sinus rhythm strip contains a single early beat that is wide and bizarre, has no preceding P wave, and has a T wave that points opposite to the QRS. What is the beat?

a.Premature ventricular contraction
b.Premature atrial contraction
c.Paced beat
d.Artifact

Explanation

A premature ventricular contraction originates below the bundle of His, so the impulse travels cell to cell rather than through the fast conduction system, producing a wide bizarre QRS with no preceding P wave and opposite T wave polarity. A premature atrial contraction stays narrow. A paced beat is preceded by a sharp pacer spike, and artifact does not interrupt the underlying R-R cycle in this way.

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