A patient who has chronic heart failure tells the nurse, 'I was fine when I went to bed, but I woke up in the middle of the night feeling like I was suffocating!' The nurse will document this assessment finding as

Correct Answer: C

Rationale: Paroxysmal nocturnal dyspnea is caused by the reabsorption of fluid from dependent body areas when the patient is sleeping and is characterized by waking up suddenly with the feeling of suffocation. Pulsus alternans is the alteration of strong and weak peripheral pulses during palpation. Orthopnea indicates that the patient is unable to lie flat because of dyspnea. Pleural effusions develop over a longer time period.

Correct Answer: D

Rationale: The subclavian artery gives rise to the vertebral artery and internal thoracic artery, but not the occipital artery (a branch of the external carotid).

Correct Answer: D

Rationale: The QRS wave marks ventricular depolarization, followed by isovolumic contraction as ventricles begin to contract.

Correct Answer: C

Rationale: Capillaries have the greatest total cross-sectional area, facilitating exchange.

Correct Answer: B

Rationale: In steady state, venous return equals cardiac output to maintain circulation.