A patient had a myocardial infarction that damaged the SA node, which is no longer functioning as the pacemaker of the heart. What heart rate would the healthcare provider expect the patient to have?
A)60 to 70 beats/min
B)40 to 60 beats/min
C)30 to 40 beats/min
D)10 to 20 beats/min

Question

Quizplus · Accepted Answer

If the SA node is damaged, then the AV node will become the heart's pacemaker at a rate of approximately 40 to 60 spontaneous depolarizations per minute. The SA node normally fires at a rate of 60 to 100 beats/min. The Purkinje fibers can function as the heart's pacemaker and will fire at a rate of around 40 beats/min.

A Patient Had a Myocardial Infarction That Damaged the SA