Nokea
Which term refers to the ability of the heart to initiate impulses repetitively and spontaneously?
- A. Contractility
- B. Excitability
- C. Automaticity
- D. Rhythmicity
Correct Answer: C
Rationale: The correct answer is C: Automaticity. Automaticity refers to the ability of the heart to generate electrical impulses spontaneously, without external stimulation. This allows the heart to initiate its own contractions independently of external influences. Contractility (A) refers to the ability of the heart muscle to contract in response to an electrical stimulus. Excitability (B) refers to the ability of cardiac cells to respond to an electrical stimulus. Rhythmicity (D) refers to the regularity of the heart's electrical impulses. Thus, C is the correct answer as it specifically addresses the heart's ability to generate impulses spontaneously.
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What is the term for the amount of blood ejected by the left ventricle into the aorta per beat, determined by preload, contractility, and afterload?
- A. Stroke volume
- B. Cardiac output
- C. End-diastolic volume
- D. Ejection fraction
Correct Answer: A
Rationale: The correct answer is A: Stroke volume. Stroke volume is the amount of blood ejected by the left ventricle into the aorta per beat. Preload (end-diastolic volume), contractility, and afterload influence stroke volume. Cardiac output (B) is the total volume of blood pumped by the heart per minute. End-diastolic volume (C) is the volume of blood in the ventricle before contraction. Ejection fraction (D) is the percentage of blood ejected from the ventricle during systole.
You have just received change-of-shift report about these patients on the coronary step down unit. Which one will you assess first?
- A. A 26-year-old with heart failure caused by congenital mitral stenosis who is scheduled for balloon valvuloplasty later today.
- B. A 45-year-old with constrictive cardiomyopathy who developed acute dyspnea and agitation about 1 hour before the shift change.
- C. A 56-year-old who had a coronary angioplasty and stent placement yesterday and has complained of occasional chest pain since the procedure.
- D. A 77-year-old who transferred from intensive care 2 days ago after coronary artery bypass grafting and has a temperature of 100.6°F.
Correct Answer: B
Rationale: Acute dyspnea and agitation suggest worsening heart failure or another urgent condition.
When administering dobutamine to a client, what is the most important parameter to assess?
- A. Blood pressure
- B. Heart rate
- C. Oxygen saturation
- D. Respiratory rate
Correct Answer: A
Rationale: The correct answer is A: Blood pressure. When administering dobutamine, a medication that increases heart contractility, the most important parameter to assess is blood pressure. This is because dobutamine can cause significant changes in blood pressure, including hypotension or hypertension, which can have serious implications for the client's hemodynamic stability. Monitoring blood pressure allows for timely intervention and adjustment of the medication dosage to ensure optimal cardiovascular function. Heart rate (B), oxygen saturation (C), and respiratory rate (D) are also important parameters to monitor but are not the primary concern when administering dobutamine, as its effects on blood pressure are more critical for patient safety and treatment efficacy.
The healthcare provider is administering IV nitroglycerin to a patient for chest pain. What is the most critical parameter to monitor?
- A. Heart rate
- B. Blood pressure
- C. Oxygen saturation
- D. Respiratory rate
Correct Answer: B
Rationale: The correct answer is B: Blood pressure. When administering IV nitroglycerin for chest pain, monitoring blood pressure is critical due to its vasodilatory effect, which can cause hypotension. Monitoring blood pressure helps prevent potential adverse effects like hypotension-related symptoms or complications. Heart rate, oxygen saturation, and respiratory rate are also important parameters to monitor, but blood pressure takes precedence in this scenario due to the potential for significant hemodynamic changes.
The client on nitroglycerin patches reports dizziness when standing up. What is the nurse's best response?
- A. Advise the client to rise slowly to prevent dizziness.
- B. Instruct the client to discontinue the nitroglycerin patches.
- C. Encourage the client to rest and avoid physical activity.
- D. Suggest the client take an over-the-counter antiemetic.
Correct Answer: A
Rationale: The correct response is A: Advise the client to rise slowly to prevent dizziness. Nitroglycerin patches can cause orthostatic hypotension, leading to dizziness when standing up quickly. By advising the client to rise slowly, the nurse can help prevent a sudden drop in blood pressure and reduce the risk of dizziness and falls. This response promotes client safety and addresses the underlying cause of the symptom.
Choices B, C, and D are incorrect:
B: Instructing the client to discontinue nitroglycerin patches is not appropriate without consulting the healthcare provider. Abruptly stopping nitroglycerin can lead to serious complications.
C: Encouraging the client to rest and avoid physical activity does not address the issue of orthostatic hypotension caused by nitroglycerin patches.
D: Suggesting an over-the-counter antiemetic is not indicated for dizziness related to orthostatic hypotension. It does not address the underlying cause