Cardiovascular System Exam Questions

Correct Answer: A

Rationale: Cardiomyopathy is the correct answer. In cardiomyopathy, the heart muscle becomes weak and cannot pump blood effectively, which can lead to heart failure. Myocarditis (choice B) is inflammation of the heart muscle, not specifically causing muscle weakness. Endocarditis (choice C) is an infection of the inner lining of the heart chambers and valves. Pericarditis (choice D) is inflammation of the pericardium, the outer lining of the heart.

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: A

Rationale: Arrhythmia is the correct answer because it refers to an irregular or abnormal heart rhythm, which can cause the heart to beat too fast, too slow, or erratically. Hypertension (choice B) is high blood pressure and not directly related to irregular heart rhythm. Tachycardia (choice C) is a condition where the heart beats too quickly, not necessarily irregularly. Bradycardia (choice D) is a condition where the heart beats too slowly, not necessarily irregularly. Therefore, only arrhythmia (choice A) fits the description provided in the question.

Correct Answer: A

Rationale: The correct answer is the Sympathetic nervous system. The sympathetic nervous system is a branch of the autonomic nervous system that is responsible for the fight-or-flight response. It causes vasodilation in central vessels to increase blood flow to vital organs during stress or exercise, while inducing vasoconstriction in peripheral vessels to redirect blood to essential areas. Norepinephrine and acetylcholine are neurotransmitters associated with the sympathetic and parasympathetic nervous systems, respectively, but they are not themselves central vasodilators and peripheral vasoconstrictors.

Correct Answer: A

Rationale: Refractoriness is the correct term to describe the inability of cardiac cells to respond to a new stimulus while they are still in contraction from a previous stimulus. This period is essential for the heart to complete its contraction and relaxation phases without interference. Excitability refers to the ability of cells to respond to stimuli, not the inability to respond. Contractility is the force of cardiac muscle contraction, and automaticity is the ability of cardiac cells to generate electrical impulses spontaneously, which are not relevant to the described scenario.