Cardiology - Cardiac Failure, Heart Sounds, and Circulatory Shock

Question 1

Failure of the heart to pump enough blood to satisfy the needs of the body.

A. cardiogenic shock
B. cardiac failure
C. hypovolemia

Answer 1

B. cardiac failure

Question 2

Explain the overall reflexes associated with compensation for cardiac failure.

Answer 2

An increase in SNS activation

A decrease in PNS activation

Question 3

What are the two immediate effects of acute heart damage.

Answer 3

• reduced cardiac output

- increased R atrial pressure —> decreased venous return

Question 4

In heart damage, the RAP raises from its normal 0 mmHg at normal cardiac output of 5LPM to ____ in the damaged heart.

A. +2 mmHg
B. +4 mmHg
C. +6 mmHg
D. +8 mmHg

Answer 4

B. +4 mmHg

Question 5

Compensatory mechanisms for the failing heart usually reach maximum effectiveness after ____ seconds of SNS activation.

Answer 5

30

Question 6

Outline the reflexes activated by the failing heart.

Answer 6

• baro-R
• chemo-R
• CNS ischemic response

Question 7

SNS activation acts to increase pre-load on the failing heart by what mechanism?

Answer 7

Vasoconstriction, which increases filling pressure, and therefore CO by the Frank-Starling mechanism.

Question 8

Explain how renal retention of fluid in damaged hearts may be beneficial

Answer 8

“All things in moderation.”

• the RAAS acts to retain sodium and fluid
  
  • increases filling pressure to improve contractility
  • reduces peripheral resistance by venodistention
• However, too much damage to the heart and, therefore, poor perfusion of the kidneys, may result in edema secondary to the kidney’s inability to maintain fluid homeostasis.
• further myocardial damage (increased stretch/workload)
• pulmonary edema
• peripheral edema

Question 9

Compensatory mechanisms may return cardiac output to _____ of the original cardiac output if all compensation works properly.

A. 1/4
B. 1/2
C. 3/4
D. the entirety

Answer 9

B. 1/2

Question 10

Severe heart damage may overwhelm the body’s natural compensatory mechanisms. When that happens, right altrial pressure may rise to as much as +5 mmHg. This RAP reduces cardiac output. What organ and/or organ system is affected by this increased RAP, and what is the result?

A. brain; altered mental status
B. spleen; increased blood reticulocyte count
C. GI system; inability to properly absorb nutrients
D. kidney; edema due to inability to filter blood

Answer 10

D. kidney; edema due to inability to filter blood

Question 11

T/F:
Fluid retention in heart failure arises from the body’s inability to filter blood. Normal salt/water retention mechanisms begin to act, retaining water 2/2 poor cardiac output in the failing heart.

Answer 11

True

Question 12

What is the significant physical exam finding associated with heart failure?

Answer 12

Respiratory distress and pulmonary edema/rales

Question 13

By what mechanism does left heart failure produce pulmonary edema?

Answer 13

As the left heart fails, blood does not return from pulmonary circulation to the left atria.
As a result, pulmonary hydrostatic pressure increases (appx. 28 mmHg or higher), filtering plasma into the alveoli.

Question 14

If cardiac output drops below levels necessary to perfuse tissues, and this failure is due to the heart itself, what type of shock is this?

A. obstructive shock
B. cardiogenic shock
C. hypovolemic shock
D. distributive shock

Answer 14

B. cardiogenic shock - this is shock due to the inability of the heart to pump blood properly

Incorrect:
A. obstructive shock - this is associated with tamponade/trauma; blood cannot return to the heart

C. hypovolemic shock - total blood volume remains normal in cardiogenic shock, so there is no hypovolemia

D. distributive shock - this is usually due to a nervous (SNS) issue causing vasodilation