Nokea
What is the ability of cardiac cells to generate an electrical impulse without being stimulated by an external source?
- A. Automaticity
- B. Contractility
- C. Conductivity
- D. Refractoriness
Correct Answer: A
Rationale: Automaticity is the ability of cardiac cells to generate an electrical impulse spontaneously without external stimulation. It is a fundamental property of specialized cardiac cells like pacemaker cells. Contractility refers to the ability of muscle cells to contract in response to an electrical stimulus. Conductivity is the ability of cardiac cells to transmit electrical impulses. Refractoriness is the period during which cardiac cells are unable to respond to a new stimulus. Therefore, in this context, the correct answer is A: Automaticity.
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What is a condition where the heart beats too slowly, reducing the amount of blood pumped to the body?
- A. Bradycardia
- B. Tachycardia
- C. Atrial fibrillation
- D. Ventricular fibrillation
Correct Answer: A
Rationale: Certainly! Bradycardia is the correct answer because it refers to a slow heart rate, leading to reduced blood flow to the body. This condition can result in symptoms like dizziness, fatigue, and fainting. Tachycardia, on the other hand, is the opposite - a fast heart rate that can also impact blood flow. Atrial fibrillation and ventricular fibrillation are irregular heart rhythms rather than slow heart rates, causing rapid and chaotic heartbeats that can be life-threatening. Therefore, the correct answer is A, bradycardia, as it specifically addresses the scenario of the heart beating too slowly.
What is a condition characterized by episodes of severe, acute shortness of breath, often occurring at night?
- A. Paroxysmal nocturnal dyspnea
- B. Sleep apnea
- C. Orthopnea
- D. Dyspnea
Correct Answer: A
Rationale: The correct answer is A: Paroxysmal nocturnal dyspnea. This condition is characterized by sudden, severe shortness of breath at night. It can be caused by heart failure or other cardiac conditions. Sleep apnea (B) is a disorder where breathing repeatedly stops and starts during sleep, not specifically related to acute shortness of breath. Orthopnea (C) is difficulty breathing while lying flat and is not specific to nighttime episodes. Dyspnea (D) is a general term for difficulty breathing and does not specifically refer to acute episodes at night.
The client on spironolactone (Aldactone) has a potassium level of 5.8 mEq/L. What is the nurse's priority action?
- A. Hold the spironolactone and notify the healthcare provider.
- B. Administer a potassium supplement.
- C. Continue the spironolactone as ordered.
- D. Increase the dose of spironolactone.
Correct Answer: A
Rationale: The correct answer is A: Hold the spironolactone and notify the healthcare provider. The priority action is to stop the medication and inform the healthcare provider because a potassium level of 5.8 mEq/L is above the normal range (3.5-5.0 mEq/L), indicating hyperkalemia. Spironolactone is a potassium-sparing diuretic that can further increase potassium levels. Continuing the medication or administering a potassium supplement would exacerbate the issue. Increasing the dose of spironolactone would be unsafe and could lead to severe complications. Therefore, holding the medication and seeking guidance from the healthcare provider is crucial in managing the client's elevated potassium level.
This term refers to a change in the inotropic state of the muscle without a change in myocardial fiber length.
- A. Contractility
- B. Excitability
- C. Refractoriness
- D. Automaticity
Correct Answer: A
Rationale: Contractility is the correct answer as it specifically refers to the ability of the heart muscle to contract with a given force without changing its length. This term is used to describe changes in the inotropic state of the muscle, which affects the strength of contraction. Excitability, refractoriness, and automaticity do not directly relate to changes in muscle contraction force without altering fiber length. Excitability is the ability of the muscle to respond to stimuli, refractoriness is the recovery period after a muscle contraction, and automaticity is the ability of certain cells to generate spontaneous electrical activity.
The laboratory tests for four patients show the following results. Which patient should the nurse teach first about preventing CAD because the patient is at the greatest risk for CAD even without other risk factors?
- A. Total cholesterol: 152 mg/dL, triglycerides: 148 mg/dL, LDL: 148 mg/dL, HDL: 52 mg/dL
- B. Total cholesterol: 160 mg/dL, triglycerides: 102 mg/dL, LDL: 138 mg/dL, HDL: 56 mg/dL
- C. Total cholesterol: 200 mg/dL, triglycerides: 150 mg/dL, LDL: 160 mg/dL, HDL: 48 mg/dL
- D. Total cholesterol: 250 mg/dL, triglycerides: 164 mg/dL, LDL: 172 mg/dL, HDL: 32 mg/dL
Correct Answer: D
Rationale: Low HDL and high LDL increase CAD risk.