1. Chapter 20 Heart Failure and Circulatory Shock
Essentials of Pathophysiology
Chapter 20 Heart Failure and Circulatory Shock

2. Pre Lecture Quiz True/False
Decreased cardiac output will lead to an increase in renal blood flow and glomerular filtration rate.
 The endothelins are potent vasodilators that are released from the endothelial cells throughout the circulation.
 Myocardial hypertrophy is a long-term mechanism by which the heart compensates for increased workload.
  Afterload represents the force that the contracting heart must generate to eject blood from the filled heart.
  Five major complications of severe shock are acute respiratory distress syndrome, acute renal failure, gastrointestinal ulceration, disseminated intravascular coagulation, and multiple organ dysfunction syndrome. F F T T T

3. Pre lecture quiz
In __________ heart failure, blood backs up in the systemic circulation, causing peripheral edema and congestion of the abdominal organs.  
The most common cause of ____________ shock is myocardial infarction.
Examples of conditions that cause __________ shock include loss of whole blood (e.g., hemorrhage), plasma loss (e.g., severe burns), or extracellular fluid (e.g., gastrointestinal fluids lost in vomiting or diarrhea).
An increase in __________ rate is an early sign of shock.
A life-threatening condition, acute __________ edema is the most dramatic symptom of left heart failure and is characterized by capillary fluid moving into the alveoli.
cardiogenic
heart 
hypovolemic
pulmonary
right

4. Standard ECG waveform Ventricular Contraction initiated
Ventricular Relaxation
Atrial Contraction initiated
Papillary Muscle Relaxation
ST segment can indicate ischemia or infarction

5. ST segment elevation ST Depression
With a 12 lead ECG certain leads can be connected to each other to reverse the R wave and accentuate the ST Elevation

6. CORORNARY OCCLUSION
total occlusion of the proximal segment of left anterior descending artery, and
severe disease involving the proximal segment of the obtuse marginal branch
Angiogram

7. High-output versus low-output failure Systolic or diastolic failure
Types of Heart Failure
High-output versus low-output failure
Is cardiac output high or low?
Systolic or diastolic failure
Is the heart failing to pump out enough blood, or failing to accept enough blood from the body and lungs?
Right-sided or left-sided failure
Is the right or left side of the heart failing?

8. Manifestations of Heart Failure
Effects of impaired pumping
Effects of decreased renal blood flow  RAA pathway
Effects of the sympathetic nervous system
Angioplasty CABG

9. Manifestations of Heart Failure
Orthopnea: Straight Breathing, ie. Must be straight upright, or difficult breathing occurs
Author: Please add title.

10. Control of Heart function
Author: Please add title.

11. Scenario:
Mr. M has heart failure and he complains of severe shortness of breath, and has fluid in his lungs. He has tachycardia, increased diastolic blood pressure, pale moist skin, and says he feels weak, dizzy, and anxious all the time.
Question:
Which of these signs and symptoms are due to decreased renal blood flow?
Which are due to the sympathetic nervous system?
Which side of his heart do you think is failing?

12. Left-Sided Heart Failure
Blood Flow
body
Systolic: LV does not pump enough blood to body
Body lacks blood
right
left
heart
heart
Lungs fill with fluid
Diastolic: LV does not accept enough blood from lungs
lungs

13. Right-Sided Heart Failure
Blood Flow
Diastolic: RV does not accept enough blood from body
body
Body fills with blood
right
left
heart
heart
Lungs do not oxygenate enough blood
Systolic: RV does not pump enough blood to lungs
lungs

14. Pulmonary Edema Capillary fluid moves into alveoli
Lung becomes stiffer
Harder to inhale
Less gas exchange in alveoli
Crackles
Frothy pink sputum
Hemoglobin not completely oxygenated

15. Question
Tell whether the following statement is true or false: The characteristic pink sputum produced is pulmonary edema is tinged with blood.

16. Answer
True In pulmonary edema, the alveolar capillary membrane is damaged, and blood from the capillaries moves into the alveoli. The blood from the capillaries causes the sputum (produced from the lower respiratory tract) to appear pink or light red.

17. Heart fails to pump blood adequately
Cardiogenic Shock
Heart fails to pump blood adequately
Decreased cardiac output lowers BP
Sympathetic system responds
Vasoconstriction increases resistance to blood flow
Increased workload on heart worsens heart failure

18. Types of Shock
Cardiogenic
Hypovolemic
Obstructive
Distributive
Septic

19. BP = CO x PR Blood Pressure
Which of the following affect CO, and which affect PR? Why?
Blood volume
Heart rate
Vasoconstriction
Angiotensin II
Aldosterone
Epinephrine
Histamine

20. Scenario: Mr. M was injured in a motorcycle accident.
On his arrival at the hospital he presented with bleeding from the right leg, restlessness, pallor, sweating, elevated heart rate, weak pulse, rapid breathing, and lack of bowel sounds; his blood pressure was slightly elevated
Question:
What has happened to this patient’s:
Stroke volume
Cardiac output
Sympathetic nervous system

21. Scenario (cont.)
Although he was given 6 units of blood, Mr. M got worse
He became lethargic and his blood pressure began to fall; he still had no bowel sounds or urine production
Question:
The intern ordered epinephrine, and Mr. M’s blood pressure increased. Why?
Later, you overhear the resident telling the intern that was not the best treatment. Why not, if it raised Mr. M’s blood pressure?

22. Scenario (cont.)
Mr. M’s blood pressure went up a bit
He has been moved out of the ICU
Question:
His chart says you should do a 24-hour urine collection. Why?

23. Scenario (cont.) Mr. M appears to be improving
He sleeps quite a lot, but his blood pressure has remained stable; he had a little urine production; and he did not eat his supper
Checking on him in the evening, you notice that he is slightly flushed, his respiration rate is a little high, and his temperature is elevated
Question:
What is happening to his peripheral resistance?
What do you expect his heart rate to be like? Why?

24. Distributive or Vasodilatory Shock
Blood vessels dilate
There is not enough blood to fill the circulatory system
Blood flow decreases
Less blood is returned to the heart
Less blood is circulated to the body

25. Question
Which type of shock is caused by low blood volume?
Cardiogenic
Hypovolemic
Distributive
Septic

26. Answer
Hypovolemic
Hypo (low) volemia (blood volume) occurs when a patient has lost blood due to trauma, surgery, or third space fluid loss.

27. Causes of Distributive Shock
Decreased sympathetic activity: neurogenic
Brain or spine injury; anesthetics; insulin shock; emotion
Vasodilator substances in blood
Type I hypersensitivity (anaphylactic shock)
Inflammatory response to infection (sepsis)
Vessel damage from severe hypovolemia

28. Mechanism of Type I Hypersensitivity
Mast cell
Allergen
Mechanism of Type I Hypersensitivity
Granules released: Histamine, acetylcholine, kinins, leukotrienes, and prostaglandins all cause vasodilation
IgE attaches to mast cell
Allergen
attaches
to IgE
Mast cell degranulates

29. Anaphylaxis
Systemic response to the inflammatory mediators released in type I hypersensitivity
Histamine, acetylcholine, kinins, leukotrienes, and prostaglandins all cause vasodilation
What will happen when arterioles vasodilate throughout the body?
Acetylcholine, kinins, leukotrienes, and prostaglandins all can cause bronchoconstriction
What will happen when the bronchioles constrict?

30. Sepsis or Systemic Inflammatory Response Syndrome (SIRS)
Inflammatory mediators released into the circulation
Tumor necrosis factor
Interleukins
Prostaglandins
Cause systemic signs of inflammation
Fever and increased respiration, respiratory alkalosis, vasodilation, warm flushed skin
Activate inflammatory pathways
Coagulation, complement

31. Sepsis or Systemic Inflammatory Response Syndrome (SIRS) (cont.)
Discussion:
Why is septic shock called distributive?
In the later phases of septic shock, blood volume decreases. What part of the inflammatory process explains this?

32. TYPES OF SHOCK
Author: Please add title.

33. Gut Barrier Failure decreased perfusion of the gut bacterial
bacteria and
bacterial
toxins escape
endotoxins
in blood
and lymph
inflammatory
response
inflammatory
mediators in blood
vasodilation
and lymph

34. Septic Shock vasodilation decreased peripheral resistance decreased
blood pressure
SEPTIC SHOCK
40% mortality

35. The role of the endothelium in severe sepsis and multiple organ dysfunction syndrome
Septic Shock
Also called systemic inflammatory response syndrome (SIRS)
Inflammatory mediators also increase the metabolic rate of tissues, so they need more oxygen

36. The role of the endothelium in severe sepsis and multiple organ dysfunction syndrome
inflammatory
mediators
vascular endothelial cells
respond and:
promote
create
produce more
clot
adhesive
vasodilation
formation
molecules
substances (NO)
more WBCs move out into
more
the tissues and release more
vasodilation
inflammatory mediators
(Aird, W. C. [2003.] The role of the endothelium in severe sepsis and multiple organ dysfunction syndrome. Blood 101[10], Retrieved February 10, 2004, from journal.org/cgi/content/full/101/10/3765.0)

37. Septic Shock (cont.)
“Despite the prompt implementation of appropriate antibiotic therapy, sepsis mortality remains high, in the range of 28% to 50%.”
“Second, patients with culture-positive and culture-negative sepsis or septic shock have comparable mortality rates.”
(Aird, W. C. [2003.] The role of the endothelium in severe sepsis and multiple organ dysfunction syndrome. Blood 101[10], Retrieved February 10, 2004, from journal.org/cgi/content/full/101/10/3765.0)

38. Septic Shock (cont.)
“Third, administration of anti-endotoxin antibodies in large, clinical trials did not improve survival.”
(Aird, W. C. [2003.] The role of the endothelium in severe sepsis and multiple organ dysfunction syndrome. Blood 101[10], Retrieved February 10, 2004, from journal.org/cgi/content/full/101/10/3765.0)

39. Question
Which type of shock is the result of a severe allergic reaction?
Cardiogenic
Obstructive
Anaphylactic
Septic

40. Answer
Anaphylactic
Anaphylactic shock is caused when inflammatory mediators are released (type I hypersensitivity reaction). The mediators include histamine, acetylcholine, kinins, leukotrienes, and prostaglandins, all of which cause vasodilation.

41. The main function of protein C is its anticoagulant property as an inhibitor of coagulation factors V and VIII
Activated Protein C
Drotrecogin alpha - a recombinant form of human activated protein C that has anti-thrombotic, anti- inflammatory, and profibrinolytic properties - a treatment for severe sepsis
Blocks clotting
Blocks inflammation
Increases survival of the most seriously ill sepsis patients
May cause bleeding!

42. Complications of Shock
Scenario:
A doctor has been called in to treat Mr. M and has started him on fluid and antibiotics
You are warned to watch him carefully for any signs of respiratory distress
Question:
Why would blood pressure imbalances cause respiratory distress?

43. Complications of Shock (cont.)
Acute respiratory distress syndrome
Acute renal failure
Gastrointestinal complications
Disseminated intravascular coagulation
Multiple organ dysfunction syndrome

44. Acute Respiratory Distress Syndrome (ARDS)
Exudate enters alveoli
Blocks gas exchange
Makes inhaling more difficult
Neutrophils enter alveoli
Release inflammatory mediators
Release proteolytic enzymes

45. Acute Renal Failure (ARF)
Renal vasoconstriction cuts off urine production
Acute renal failure
Continued vasoconstriction cuts off renal oxygen supply
Renal tubular cells die
Acute tubular necrosis

46. Disseminated Intravascular Coagulation (DIC)
pathways
activated
clots in
platelets
many
and
small
clotting
blood
proteins
vessels
used up
microinfarcts,
bleeding
ischemia
problems

47. Multiple Organ Dysfunction Syndrome (MODS)
The most frequent cause of death in the noncoronary intensive care unit
Mortality rates vary from 30% to 100%
Mechanism not known

48. Question
Tell whether the following statement is true or false: Treatment for ARDS often includes breathing assistance using mechanical ventilation.

49. Answer
True Because alveoli are filled with exudate and blood that has leaked from the capillary, the surface area available for gas exchange is greatly reduced. Most patients will require ventilatory support until the process reverses. ARDS has a high mortality rate because it is difficult to ventilate these patients.