A patient's cardiac output is being evaluated. If the patient has a heart rate of 75 beats per minute and a stroke volume of 70 mL, which of the following represents the calculated cardiac output (CO)?
A.6.00 L/min
B.3.75 L/min
C.5.25 L/min
D.4.50 L/min
C.
5.25 L/min
That's right!
Cardiac output is calculated by multiplying heart rate by stroke volume (75×70=5250 mL), then converting to liters.
Which finding is the most specific indicator of myocardial injury when reviewing laboratory results in the emergency department?
A.
Elevated Troponin I or T
B.
Elevated Creatine kinase (CK)
C.
Elevated B-type natriuretic peptide (BNP)
D.
Elevated Myoglobin
A.
Elevated Troponin I or T
Right answer
Troponin subtypes I and T are specific to cardiac muscle and are not detectable in healthy individuals.
A patient with heart failure has an S3 heart sound auscultated during a physical exam. What is the physiological cause of the 'lub' and 'dub' sounds (S1 and S2) that precede this extra sound?
A.Turbulent blood flow across diseased valves
B.Closure of the heart valves
C.Contraction of the atrial and ventricular muscle fibers
D.Opening of the semilunar valves during systole
B.
Closure of the heart valves
Right answer
S1 is caused by the closure of the AV valves (mitral/tricuspid), and S2 is caused by the closure of the semilunar valves.
Which part of the cardiac conduction system is known as the 'pacemaker' because it normally initiates the electrical impulse at a rate of 60 to 100 beats per minute?
A.
Purkinje fibers
B.
Atrioventricular (AV) node
C.
Bundle of His
D.
Sinoatrial (SA) node
A.
Purkinje fibers
Purkinje fibers represent the terminal end of the conduction system and trigger ventricular contraction.
B.
Atrioventricular (AV) node
Not quite
The AV node is a backup pacemaker with an intrinsic rate of 40 to 60 beats per minute.
C.
Bundle of His
The Bundle of His transmits the impulse from the AV node to the bundle branches.
D.
Sinoatrial (SA) node
Right answer
The SA node is the primary pacemaker that initiates the impulse throughout the atria.
Which chemical substance, released by the kidneys, causes intense vasoconstriction and promotes the retention of salt and water?
A.Angiotensin II
B.Bradykinin
C.Histamine
D.Serotonin
A.
Angiotensin II
Right answer
Angiotensin II is a potent vasoconstrictor that also signals the kidneys to retain salt and water.
During the assessment of a patient with suspected peripheral vascular disease, the nurse notes a moderate indentation at the ankle that subsides rapidly after pressure is released. How should this be documented?
A.2+ pitting edema
B.1+ pitting edema
C.4+ pitting edema
D.3+ pitting edema
A.
2+ pitting edema
Moderate pitting that subsides rapidly is specifically graded as 2+ according to the standardized scale.
A patient with chronic arterial occlusive disease describes pain in the calf that begins after walking one block and disappears with rest. Which term should the nurse use to document this symptom?
A patient with chronic arterial occlusive disease describes pain in the calf that begins after walking one block and disappears with rest. Which term should the nurse use to document this symptom?
A.
Orthopnea
B.
Venous stasis dermatitis
C.
Rest pain
D.
Intermittent claudication
D.
Intermittent claudication
Right answer
This condition involves ischemic muscle pain triggered by exercise and relieved by rest as metabolic demands decrease.
Which laboratory result is specifically utilized to differentiate between dyspnea caused by heart failure and dyspnea resulting from pulmonary issues?
A.
Lactate dehydrogenase (LDH)
B.
C-reactive protein (CRP)
C.
Arterial blood gases (ABGs)
D.
B-type natriuretic peptide (BNP)
A.Lactate dehydrogenase (LDH)Not quiteLDH is a cardiac enzyme that rises with myocardial damage but is not the primary tool for heart failure assessment.
B.C-reactive protein (CRP)CRP is a marker for systemic inflammation and risk of coronary syndrome, not a specific tool for dyspnea differentiation.
C.Arterial blood gases (ABGs)ABGs assess acid-base balance and oxygenation but do not pinpoint the cardiac vs. pulmonary origin of dyspnea.
D.B-type natriuretic peptide (BNP)
Right answer
BNP levels elevate when the ventricles stretch and dilate, serving as a specific marker for the severity of heart failure.
16 / 30
A patient's ECG shows a wavy baseline between QRS complexes with an irregular ventricular rate of 120 beats per minute and no discernible P waves. Which dysrhythmia is this?
A.Ventricular Tachycardia
B.Sinus Tachycardia
C.Premature Ventricular Contractions (PVCs)
D.Atrial Fibrillation
D.
Atrial Fibrillation
Right answer
Atrial fibrillation is characterized by an irregular rhythm, no measurable P waves, and a wavy baseline.
A nurse is reviewing blood gas results for a patient in heart failure. The results show pH 7.31, PaCO2 40, and HCO 3−18. How should this be interpreted?
A.
Respiratory Acidosis
B.
Metabolic Acidosis
C.
Respiratory Alkalosis
D.
Metabolic Alkalosis
B.
Metabolic Acidosis
Right answer
A low pH (<7.35) combined with a low HCO3− (<22) and a normal PaCO2 indicates a metabolic origin for the acidosis.
Which of the following sets of physiological changes describes the effect of parasympathetic stimulation on the heart via the vagus nerve?
A.
Increased heart rate, slowed AV node conduction, and increased strength of contraction
B.
Increased heart rate, increased conduction speed, and increased contractility
C.
Decreased heart rate, increased conduction speed, and decreased contractility
D.
Decreased heart rate, slowed AV node conduction, and decreased strength of contraction
D.
Decreased heart rate, slowed AV node conduction, and decreased strength of contraction
Right answer
Parasympathetic fibers found in the SA and AV nodes slow the heart's rate and conduction when stimulated.
The nurse is preparing a patient for a coronary angiography (cardiac catheterization). Which assessment is the priority before the procedure begins?
A.
Evaluating the patient's level of anxiety
B.
Assessing for allergies to seafood or iodine
C.
Determining the patient's height and weight
D.
Calculating the patient's pulse pressure
B.
Assessing for allergies to seafood or iodine
That's right!
Contrast dye used in angiography contains iodine, making the assessment for allergies crucial to prevent anaphylaxis.
12 / 30
A patient is taking warfarin (Coumadin) for atrial fibrillation. Which laboratory test will the nurse monitor to adjust the dosage of this medication?
A.
Activated partial thromboplastin time (aPTT)
B.
Platelet count
C.
Serum troponin levels
D.
Prothrombin time (PT) and International Normalized Ratio (INR)
D.
Prothrombin time (PT) and International Normalized Ratio (INR)
That's right!
Warfarin dosage is specifically adjusted based on the patient's PT and INR results.
What is the primary purpose of the 'Allen test' when performed on a patient prior to certain medical procedures?
A.To evaluate the presence of deep vein thrombosis
B.To determine the adequacy of arterial circulation to the hand
C.To measure the severity of pitting edema in the upper extremities
D.To detect bruits in the carotid arteries
B.
To determine the adequacy of arterial circulation to the hand
Right answer
The Allen test checks the patency of the radial and ulnar arteries to ensure the hand remains perfused if one artery is compromised.
Which medication is specifically used to increase the heart rate in a patient experiencing symptomatic sinus bradycardia?
A.Digoxin (Lanoxin)
B.Lidocaine (Xylocaine)
C.Atenolol (Tenormin)
D.Atropine sulfate
A.
Digoxin (Lanoxin)
Digoxin slows the heart rate (negative chronotropic effect) and would worsen bradycardia.
B.
Lidocaine (Xylocaine)
Lidocaine is an antidysrhythmic used for ventricular rhythms, not for increasing the sinus rate.
C.
Atenolol (Tenormin)
Atenolol is a beta-blocker that reduces heart rate and blood pressure.
D.
Atropine sulfate
That's right!
Atropine acts as a vagal blocker to increase the heart rate in symptomatic bradycardia and heart blocks.
A nurse is teaching a patient about a newly prescribed ACE inhibitor. Which statement by the nurse accurately describes the drug's primary therapeutic action?
A.
It slows the heart rate by delaying impulse conduction through the AV node.
B.
It dilates arteries and decreases resistance to blood flow by blocking aldosterone release.
C.
It blocks calcium channels to relax coronary arteries and prevent spasms.
D.
It increases the force of myocardial contraction to improve stroke volume.
Focus on the role of the renin-angiotensin-aldosterone (RAA) system in blood pressure regulation.
B.
It dilates arteries and decreases resistance to blood flow by blocking aldosterone release.
Right answer
ACE inhibitors work against the renin-angiotensin-aldosterone system to reduce afterload and fluid retention.
When interpreting an ECG strip, the nurse notes that the PR interval is 0.24 seconds. What does this finding indicate?
A.
Normal conduction through the atria and AV junction
B.
A delay in conduction through the ventricles
C.
Rapid depolarization of the atria
D.
A delay in conduction from the SA node to the AV node
D.
A delay in conduction from the SA node to the AV node
Right answer
The normal PR interval is 0.12 to 0.20 seconds; values exceeding this indicate an interference or delay in conduction.
According to the source material, which of the following is an age-related change in the cardiovascular system that contributes to postural hypotension?
A.
Decreased peripheral vascular resistance
B.
Increase in SA node pacemaker cells
C.
Slower adaptation of the system to changes in position
D.
Decrease in heart muscle density
C.
Slower adaptation of the system to changes in position
Right answer
The aging cardiovascular system adapts more slowly to position changes, frequently resulting in postural hypotension.
Which of the following describes the correct pattern and reasoning for heart sound auscultation using a stethoscope?
A.
The bell is used at the apex while the patient is on the left side to best hear S 3 and S 4
.
B.
The diaphragm is used at the base to hear S 1 louder than S 2
.
C.
The bell is used to detect heart murmurs because they are always high-pitched sounds.
D.
The diaphragm is pressed lightly to hear low-pitched atrial gallops (S 4)
A.
The bell is used at the apex while the patient is on the left side to best hear S3 and S4.
Right answer
Extra heart sounds like S3 and S4 are low-pitched and heard best with the bell at the apex in the left lateral position.
24 / 30
A patient with peripheral vascular disease is prescribed pentoxifylline (Trental). What is the primary therapeutic goal of this 'hemorheologic' agent?
A.
To cause rapid vasodilation of the coronary arteries
B.
To lower systemic blood pressure by blocking calcium entry
C.
To prevent the formation of new venous thrombi
D.
To increase the flexibility of RBCs to allow passage through small vessels
D.
To increase the flexibility of RBCs to allow passage through small vessels
That's right!
Trental decreases blood viscosity and increases RBC flexibility to improve flow in patients with intermittent claudication.
The 'first heart sound' (S1) is referred to as 'lub'. According to the source, when exactly does this sound occur?
A.At the very end of diastole during the 'atrial kick'
B.When the ventricles contract and the mitral and tricuspid valves close
C.When the pulmonic valve opens to allow blood into the pulmonary artery
D.During ventricular relaxation when the aortic valve closes
B.
When the ventricles contract and the mitral and tricuspid valves close
Right answer
S 1 marks the beginning of systole as the AV valves shut to prevent backflow into the atria.
Which of the following factors would lead to an increase in 'afterload' within the cardiovascular system?
A.
Overhydration
B.
Systemic vasodilation
C.
Systemic vasoconstriction
D.
Hemorrhage
A.
Overhydration
Overhydration increases preload (end-diastolic volume/pressure) rather than afterload.
B.
Systemic vasodilation
Not quite
Vasodilation decreases afterload by reducing the pressure the ventricles must overcome to eject blood.
C.
Systemic vasoconstriction
Right answer
Vasoconstriction increases the pressure in the arterial system, raising the workload required for the ventricles to eject blood.
D.
Hemorrhage
Hemorrhage leads to decreased blood volume, which primarily reduces preload.
The nurse notes a reddish-brown discoloration called 'rubor' in a patient's lower extremity when it is in a dependent position. What does this finding suggest?
A.
Chronic venous insufficiency
B.
Lymphatic dysfunction
C.
Arterial occlusive disease
D.
Deep vein thrombosis (DVT)
C.
Arterial occlusive disease
Right answer
Rubor in a dependent lower extremity is a classic sign of arterial occlusive disease and inadequate blood flow
20 / 30
The 'atrial kick' occurs at the end of which phase of the cardiac cycle, and what is its purpose?
A.Systole; to eject blood into the aorta
B.Systole; to close the mitral and tricuspid valves
C.Diastole; to eject more blood into the ventricles
D.Repolarization; to restore the resting electrical state
C.
Diastole; to eject more blood into the ventricles
Right answer
At the end of diastole (the relaxation/filling phase), the atria contract to provide the final 'atrial kick' of blood into the ventricles.
25 / 30
What happens during the 'repolarization' process of a cardiac cell?
A.The resting state is restored where the inside of the cell is more negative than the outside.
B.The ventricles contract and eject blood into the systemic circulation.
C.The cell loses its internal negativity as an electrical wave moves through the heart.
D.The AV node generates an impulse at 40 to 60 beats per minute.
A.
The resting state is restored where the inside of the cell is more negative than the outside.
Right answer
Repolarization is the process of restoring the electrically polarized resting state of the cardiac cells.