Correct Answer: A

Rationale: Tachycardia is the correct answer because it is a condition characterized by a fast heart rate, which can decrease the heart's efficiency in pumping blood. Bradycardia, on the other hand, refers to a slow heart rate, which is the opposite of what is described in the question. Arrhythmia is a general term for any irregularity in the heart's rhythm, not necessarily specifically related to a fast heart rate. Ventricular fibrillation is a life-threatening arrhythmia where the heart's lower chambers quiver instead of pumping blood effectively, but it is not specifically characterized by a fast heart rate.

Correct Answer: A

Rationale: The correct answer is A: Cardiac output. Cardiac output is the volume of blood pumped by the heart per minute. It is calculated by multiplying the stroke volume (the amount of blood pumped out of the heart in each beat) by the heart rate (number of heartbeats per minute). This question specifically asks for the total amount of blood pumped through the circulatory system in a minute, which is represented by cardiac output. Choices B, C, and D are incorrect because stroke volume refers to the amount of blood pumped out of the heart in each beat, end-diastolic volume is the volume of blood in the heart at the end of diastole, and ejection fraction is the percentage of blood pumped out of the heart with each contraction, not the total amount pumped per minute.

Correct Answer: A

Rationale: An INR of 5.5 is significantly elevated, indicating an increased risk of bleeding. The priority nursing action in this situation is to administer vitamin K as an antidote to reverse the effects of warfarin and lower the INR. Holding the next dose of warfarin (choice B) is important but not as immediate as administering vitamin K. Increasing the dose of warfarin (choice C) would further elevate the INR, worsening the bleeding risk. Administering fresh frozen plasma (choice D) is not the first-line treatment for high INR due to warfarin.

Correct Answer: D

Rationale: The correct answer is D: Notify the healthcare provider immediately. If a client on nitroglycerin reports chest pain, the priority action is to notify the healthcare provider immediately. This is crucial to ensure prompt reassessment of the client's condition and treatment plan. Administering nitroglycerin, morphine, or aspirin without consulting the healthcare provider first can be risky as the chest pain may indicate a need for a change in treatment or further evaluation. Administering medications without proper assessment and guidance can lead to complications and is not recommended in this scenario.

Correct Answer: A

Rationale: The correct answer is A: Heart failure. Heart failure occurs when the heart is unable to pump blood effectively, resulting in a buildup of fluid in the lungs and other parts of the body. Choice B, Cardiomyopathy, refers to diseases of the heart muscle, not specifically the inability to pump blood effectively. Choice C, Myocardial infarction, is a heart attack caused by a blocked blood supply to the heart muscle, not directly related to the heart's pumping efficiency. Choice D, Pulmonary edema, is a condition characterized by fluid accumulation in the lungs, often a consequence of heart failure but not the primary condition described in the question.