Chapter 39 Cardiogenic shock

Question 1

Reasons for diastolic dysfunction?

Answer 1

• Cardiac tamponade
• HCM
• Tachyarrhythmia

Question 2

Reasons for decreased outflow with systolic dysfunction?

Answer 2

• Severe regurgitation (ruptured chord tendinae)
• Aortic stenosis
• Hypertrophic obstructive cardiomyopathy

Question 3

Reasons for decreased contractility with systolic dysfunction

Answer 3

• DCM
• Sepsis
• Endomyocarditis
• Myocardial infarction

Question 4

What are two reasons for tachycardia in cardiogenic shock.

Answer 4

1. Decreased cardiac output -> hypotension -> increased sympathetic tone -> tachycardia
2. Malignant tachycardia -> not allowing adequate diastolic filling -> hypotension

Question 5

How does sepsis cause cardiogenic shock

Answer 5

A dysfunction of the myocardium (reduction in ventricular compliance, biventricular dilation, and decrease in contractile function) contribute to the decrease in ejection fraction.

Question 6

When does the myocardial dysfunction in sepsis peak and when does it resolve?

Answer 6

Myocardial dysfunction peak days of onset of sepsis. It resolves after 7-10 days.

Question 7

What electrolyte disturbance can be seen with cardiac tamponade?

Answer 7

Increased K, decreased Na from a reduced effective circulating volume induced pseudohypoadrenocorticism.

Question 8

A previously healthy cat was neutered and a few days ago and has now developed cardiac dysfunction with hypotension, pulmonary edema, and interstitial pneumonia. Dr. Lowe thinks the cat has myocardial endocarditis and Dr. Her thinks the cat has a myocardial infarction. Who is most likely to be right?

Answer 8

Dr. Lowe. The cat is much more likely to have myocardial endocarditis.

Question 9

A dog has a bradyarrythmia with 20 escape beats per minute. Dr. Arnold insists that the escape beats are originating from the bundle of His while while Dr. Gautier is absolutely sure that the distal purkinje fibres are producing the ectopic beats. Who is right?

Answer 9

Dr. Gautier. The bundle of His is producing 40 to 60 beats/min and the distal Purkinje fibers producing 20 to 40 beats/min.

Question 10

Dr. Her is working on a cat with 3rd degree AV block. He tells Dr. Lowe that cats typically have a higher ventricular escape rhythm of 100 to 140 beat/min that is likely the reason why the cat did not present in cardiogenic shock or had episodes of syncope. If Dr. Her lying or not?

Answer 10

Of course Dr. Her is not lying.