Nursing Elites

1. What does the PR interval measure?

• A. Time it takes for the electrical impulse to travel from the atria to the ventricles
• B. Measurement of ventricular depolarization
• C. Duration of ventricular repolarization
• D. Segment representing the time between ventricular depolarization and repolarization

Correct answer: A

Rationale: The PR interval measures the time it takes for the electrical impulse to travel from the atria to the ventricles. It is crucial in diagnosing heart rhythm disorders, as abnormalities in this interval can indicate conduction abnormalities between the atria and ventricles. Choices B, C, and D are incorrect. The QRS complex represents ventricular depolarization, the QT interval represents the duration of ventricular repolarization, and the ST segment represents the time between ventricular depolarization and repolarization.

2. What is the procedure where a device is used to shock the heart back into a normal rhythm during a life-threatening arrhythmia?

• A. Defibrillation
• B. Cardioversion
• C. Echocardiogram
• D. Ablation

Correct answer: A

Rationale: The correct answer is A, Defibrillation. Defibrillation is the procedure of using a device to deliver an electric shock to the heart during life-threatening arrhythmias like ventricular fibrillation or ventricular tachycardia to restore a normal rhythm. Choice B, Cardioversion, is similar but is typically used for less severe arrhythmias. Choice C, Echocardiogram, is a diagnostic test that uses sound waves to create images of the heart. Choice D, Ablation, is a procedure to treat certain types of arrhythmias by scarring or destroying tissue that triggers abnormal electrical signals.

3. Which chronic condition is characterized by abnormally thickened heart muscle, making it harder for the heart to pump blood efficiently?

• A. Hypertrophic cardiomyopathy
• B. Dilated cardiomyopathy
• C. Restrictive cardiomyopathy
• D. Ventricular hypertrophy

Correct answer: A

Rationale: Hypertrophic cardiomyopathy is the correct answer. In this condition, the heart muscle becomes abnormally thickened, leading to difficulties in pumping blood efficiently. Dilated cardiomyopathy (choice B) involves the enlargement of the heart chambers, not thickening of the heart muscle. Restrictive cardiomyopathy (choice C) is characterized by stiffening of the heart muscle, impairing its ability to fill properly. Ventricular hypertrophy (choice D) refers to the thickening of the heart's ventricle walls, which can result from various conditions, not solely hypertrophic cardiomyopathy.

4. Which neurotransmitter released by the parasympathetic nervous system can decrease heart rate?

• A. Acetylcholine
• B. Norepinephrine
• C. Dopamine
• D. Serotonin

Correct answer: A

Rationale: Acetylcholine is the correct answer. It is a neurotransmitter released by the parasympathetic nervous system that can decrease heart rate. Norepinephrine, dopamine, and serotonin are neurotransmitters that usually have different effects on the body and are not specifically associated with decreasing heart rate. Norepinephrine, for example, is often related to the fight-or-flight response and can increase heart rate.

5. This is a more accurate indicator of tissue perfusion. It represents the cardiac output in terms of liters per minute per square meter of body surface area. Its normal range is 2.4-4 L/min.

• A. Cardiac Index
• B. Stroke volume
• C. Ejection fraction
• D. Cardiac output

Correct answer: A

Rationale: The correct answer is A: Cardiac Index. Cardiac Index is a measure of cardiac output relative to body surface area, providing a more accurate assessment of tissue perfusion. It is calculated by dividing the cardiac output by the body surface area. The normal range for cardiac index is 2.4-4 L/min/m². Choice B, Stroke volume, refers to the amount of blood ejected by the heart in one contraction and is not adjusted for body surface area. Choice C, Ejection fraction, is the percentage of blood pumped out of the heart's ventricles with each contraction, not adjusted for body surface area. Choice D, Cardiac output, is the total volume of blood pumped by the heart per minute, without considering body surface area.

Similar Questions