If the SA node fails, which structure can take over as pacemaker at a slower rate?
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Correct answer: AV node — 40 to 60 beats per minute
The AV node can act as a secondary pacemaker if the SA node fails, generating impulses at 40–60 bpm. Lower-order sites such as the bundle of His and Purkinje fibres can also take over but at even slower intrinsic rates.
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More Cardiac Conduction System (SA, AV Nodes) questions
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