FA Davis cardiac function

A nursing student writes in her notes, "When the heart is filled with more blood, the heart is able to eject more blood." What term would best fit this description? Cardiac output Afterload Preload Stroke volume

Preload

A patient is assessed and found to have a left ventricle ejection fraction (LVEF) of 35%. What interpretation of this result would be correct for the nurse to make? The LVEF is normal. The LVEF represents a high-functioning heart. The LVEF is reduced compared to normal values. The LVEF is incorrect and should not be expressed as a percentage.

The LVEF is reduced compared to normal values

If all people are assumed to have cardiac output of 5 L/min at rest, with a resting heart rate (HR) of 70 beats per minute (bpm), and an athlete has a resting HR of 58 bpm, which of the following likely applies? The athlete has a higher resting stroke volume. The athlete has higher afterload. The athlete has a significantly reduced ejection fraction. The athlete has higher resting blood pressure.

The athlete has a higher resting stroke volume

Blood volume influences blood pressure.

The greater the blood volume, the greater the pressure. However, sometimes, too much blood volume may lead to edema. When blood pressure is too high, the body institutes mechanisms to reduce blood volume. For example, urine output increases.

Several mechanisms exist to increase blood volume when blood pressure is too low.

The kidneys work closely with the heart and affect blood pressure by controlling blood volume. When the kidneys do not receive enough blood flow, they release renin. Renin, in turn, activates angiotensin II. Angiotensin II then stimulates aldosterone. Renin, angiotensin, and aldosterone function together and are often referred to as the renin-angiotensin-aldosterone system—or R.A.A.S. for short. As part of the R.A.A.S, angiotensin II causes vasoconstriction, which increases blood pressure. Aldosterone causes sodium and water retention, increasing blood volume and blood pressure.

A patient is given an angiotensin receptor blocker. As the nurse with the discharge instructions, which of the following would you tell the patient is the effect of this medication? The medication increases heart rate. The medication decreases pulmonary congestion. The medication decreases the constriction and resistance of your blood vessels. The medication increases urine output.

The medication decreases the constriction and resistance of your blood vessels

the heart is excellent at adjusting to the body's demands. However, like any other body tissue, the heart can have problems and begin to fail. Problems leading to heart failure can happen in the heart itself. In ischemic heart disease,

a portion of the heart does not receive enough oxygen. Heart cells begin to die and the heart is unable to pump blood effectively. Sometimes the heart suffers from dysrhythmias. Dysrhythmias cause the heart to contract in an uncoordinated manner.

Let's start with cardiac output, which is the

amount of blood the left ventricle pumps each minute.

Contractility is dependent on

calcium levels.

Which term refers to the heart's force of contraction? Preload Chronotropic function Afterload Contractility

contractility

If blood volume decreases, then blood pressure may Increase or Decrease

decrease Blood volume and blood pressure are closely related. Without enough fluid in the circulatory system, pressure will fall. Next

If afterload increases, then stroke volume Increases or Decreases

decreases Afterload is the resistance the heart must work against. The greater the resistance, the less blood the heart is able to eject each beat.

If angiotensin II is inhibited, then vasoconstriction Increases or Decreases

decreases Angiotensin II, part of the RAAS, is a potent vasoconstrictor.

Contractility, which is the

heart's force of contraction, can also be changed.

If blood pressure decreases, then compensatory measures cause heart rate to Increase or Decrease

increase The baroreceptors in the aorta and carotids monitor blood pressure. When they detect a fall in blood pressure, they activate the sympathetic nervous system, which in turn stimulates heart rate to compensate for the pressure drop.

A trauma patient is experiencing a decrease in urine output. The patient has experienced significant blood loss. Which is one factor that accounts for the decrease in urine output? Decreased aldosterone secretion Suppression of the renin-angiotensin-aldosterone system (RAAS) Decreased sodium and water reabsorption Increased antidiuretic hormone (ADH)

increased antifdiuretic hormone (ADH)

If venous return increases, then preload Increases or Decreases

increases

If aldosterone is released, then blood volume Increases or Decreases

increases Aldosterone stimulates sodium and water retention, increasing blood volume.

If angiotensin II increases, then aldosterone Increases or Decreases

increases Angiotensin II stimulates the adrenal cortex to release aldosterone.

If blood pressure decreases, then the ADH levels Increases or Decreases

increases Low blood pressure stimulates the release of ADH, which decreases urine output and increases water retention. Increasing fluid volume in the body helps to maintain blood pressure.

If nitric oxide increases, then vasodilation Increases or Decreases

increases Nitric oxide is a potent vasodilator. Nitroglycerin tablets may be used to dilate coronary arteries when the individual experiences chest pain. Next

If preload increases within a normal range, then stroke volume Increases or Decreases

increases Preload refers to the volume of blood filling the heart before it contracts. To a certain point, the more the heart is filled with blood, the more blood is ejected with each stroke.

If kidney perfusion decreases, then renin release Increases or Decreases

increases Renin is released by the juxtaglomerular (JG) cells of the kidney in response to low blood flow and pressure to the kidneys.

If capillary hydrostatic pressure increases, then the likelihood of edema Increases or Decreases

increases Capillary hydrostatic pressure is the fluid pressure within a capillary. As capillaries are "leaky," higher fluid pressure inside the capillary results in more fluid leaking out of the capillary.

consider that the heart does not exist in

isolation. A number of factors influence its performance, including venous return, which is the volume of blood entering the heart from the veins.

A nurse it talking to a patient who has hypertension. The nurse states that it is not only the heart that is involved in maintaining blood pressure. What other organ is the nurse most likely referring to? Liver Stomach Spleen Kidney

kidney

cardiac output is determined by

multiplying heart rate by stroke volume.

Which term indicates the volume of blood entering the heart at the end of diastole? Contractility Ejection fraction Afterload Preload

preload

A patient appears with hypotension. Which of the following may contribute to hypotension? Increased sodium and water reabsorption Increased cardiac output Reduced blood volume Activation of the renin-angiotensin-aldosterone system

reduced blood volume

Then there is afterload, which is the

resistance the heart works against. Afterload is related to blood pressure. To overcome high afterload, the heart hypertrophies. This can cause problems, as greater coronary circulation is needed to support the extra muscle tissue.

An increase in calcium within heart cells results in a

stronger contraction.

The heart, though, can be "overfilled". When this happens,

the heart is unable to contract effectively.

Venous return can also be referred to as

"preload". Generally, preload and stroke volume have a direct relationship: the higher the preload, the higher the stroke volume.

Heart failure may result from which of the following? Select all that apply. Ischemic injury to the heart Dysrhythmias Increased contractility Chronic hypoxia Hypertension Next

-ischemic injury to the heart -dysrhythmias -chronic hypoxia -hypertension

A patient has end-diastolic volume of 120 ml and end-systolic volume of 60 ml. What is the patient's stroke volume for that beat in ml/beat? Enter numeral only.

60

Which of the following responses are instituted by the body to compensate for low blood pressure? Select all that apply. Increased urine output Increased afterload Activation of the renin-aldosterone-angiotensin system Decreased sodium and water retention Increased blood volume

Activation of the renin-aldosterone-angiotensin system Increased blood volume

A patient suffers severe kidney damage and the juxtaglomerular cells are disrupted. Which of the following manifestations does the nurse expect? Elevated blood pressure (BP) Decreased renin secretion Decreased antidiuretic hormone Increased angiotensin

Decreased renin secretion

A nurse is given a patient's heart rate and stroke volume. How would she calculate the cardiac output? Heart rate times stroke volume Heart rate divided by stroke volume Heart rate plus stroke volume Stroke volume divided by heart rate

Heart rate times stroke volume

A patient's blood pressure is falling due to hemorrhage. Which of the following are appropriate compensations by the body? Select all that apply. Decreased heart rate Increased antidiuretic hormone (ADH) Increased aldosterone Decreased peripheral vasoconstriction Increased fluid retention

Increased antidiuretic hormone (ADH) Increased aldosterone Increased fluid retention

Following the development of left ventricular failure, a patient develops pulmonary edema. Which of the following factors accounts for the formation of this edema? Increased hydrostatic pressure in the pulmonary capillaries Increased oncotic pressure in the pulmonary capillaries Decreased hydrostatic pressure in the pulmonary capillaries Decreased pulmonary capillary permeability

Increased hydrostatic pressure in the pulmonary cappillaries

Following the development of left ventricular failure, a patient develops pulmonary edema. Which of the following factors accounts for the formation of this edema? Increased hydrostatic pressure in the pulmonary capillaries Increased oncotic pressure in the pulmonary capillaries Decreased hydrostatic pressure in the pulmonary capillaries Decreased pulmonary capillary permeability Hopelessness r/t perceived lack of support and ability to change the present situation Explains to visitors everything is okay, he really was fortunate it wasn't worse than it could have been, 'he will be fine', tells everyone to go home (doesn't want visitors now).

Increased hydrostatic pressure in the pulmonary cappillaries

A patient has a fluid volume overload due to congestive heart failure. Which of the following compensations will the body attempt to address the fluid volume overload? Increased renin Increased natriuretic peptide Increased angiotensinogen Increased aldosterone

Increased natriuretic peptide

Please place the following sequences in order as to how exercise can result in increased cardiac output. Increased compression of the veins Increased stroke volume Increased preload Increased venous return Increased skeletal muscle contraction

Increased skeletal muscle contraction Increased compression of the veins Increased venous return Increased preload Increased stroke volume

A patient with left ventricular failure is completing a cardiac assessment. Which of the following results would be concerning to a clinician? Left ventricular ejection fraction (LVEF) of 35% Resting cardiac output of 5.2 liters per minute Low to normal central venous pressure Blood pressure (BP) of 130/82 mm Hg

Left ventricular ejection fraction (LVEF) of 35%

A nurse needs to record the stroke volume (SV) for a patient. Which of the following units would be the proper one for stroke volume? Beats per minute Percentage Liters per minute Milliliters per beat

Milliliters per beat

Problems in other tissues may also induce heart failure.

One, hypertension, we have already discussed. In this case, high arterial blood pressure causes the heart to have to work harder. Eventually, the heart may fail. Normally, the heart and lungs work in conjunction to deliver oxygenated blood to the tissues. However, when the lungs have problems oxygenating the blood, vasoconstriction within the lungs causes the heart to have to work harder, which may lead to failure.