Chapter 7: Dysrhythmia Interpretation and Management Test Bank

1. The nurse is caring for a patient who is on a cardiac monitor. The nurse realizes that the sinus node is the pacemaker of the heart because it is: a. the fastest pacemaker cell in the heart. b. the only pacemaker cell in the heart. c. the only cell that does not affect the cardiac cycle. d. located in the left side of the heart. ANS: A The cardiac cycle begins with an impulse that is generated from a small concentrated area of pacemaker cells high in the right atria called the sinoatrial node (sinus node or SA node). The SA node has the fastest rate of discharge and thus is the dominant pacemaker of the heart. The AV node has pacemaker properties and can discharge an impulse if the SA node fails. The ventricles have pacemaker capabilities if the sinus node or the AV node ceases to generate impulses. DIF: Cognitive Level: Comprehension REF: p. 95 OBJ: Explain the relationships between electrical and mechanical events in the heart. TOP: Nursing Process Step: Assessment MSC: NCLEX: Physiological Integrity 2. One of the functions of the atrioventricular (AV) node is to: