ATI RN
Cardiovascular System Test Questions Questions
Question 1 of 5
The percent volume of whole blood occupied by packed red cells is referred to as the:
Correct Answer: A
Rationale: Hematocrit is the percentage of blood volume occupied by packed RBCs (normal: 38-50%). Formed elements include all cells, and sedimentation index relates to ESR, not volume.
Question 2 of 5
A nurse is working on a team responding to cardiac arrest in the hospital. Because the client's heart stopped, his body has gone into a state of acidosis. Which of the following medications would most likely correct metabolic acidosis that occurs during cardiac arrest?
Correct Answer: C
Rationale: Sodium bicarbonate (C) corrects metabolic acidosis during cardiac arrest by buffering excess acid (low pH) from anaerobic metabolism. Lidocaine and procainamide (A, B) treat arrhythmias, and dobutamine (D) supports heart failure, not acidosis. (Source: Document, p. 9-10)
Question 3 of 5
Which of the following events is the first to take place in a cardiac cycle?
Correct Answer: A
Rationale: The cardiac cycle begins with SA node depolarization (A), initiating the impulse that spreads across the atria (P wave, C), reaches the AV node (B), and then ventricles (QRS, D). SA node firing is the first event.
Question 4 of 5
What structures in the heart wall prevent the AV (atrioventricular) valves from opening up into the atria?
Correct Answer: A
Rationale: Papillary muscles (A) contract to pull chordae tendineae, preventing AV valves from inverting into atria during ventricular systole. Auricles (B) are atrial structures, the septum (C) separates ventricles, and endocardium (D) is a lining.
Question 5 of 5
A heart rate of less than 60 beats per minute is called
Correct Answer: D
Rationale: Bradycardia (D) is a heart rate <60 bpm. Heart block (A) is a conduction issue, tachycardia (B) is >100 bpm, and fibrillation (C) is uncoordinated beating.