Animal Models of Resus

Question 1

Which animals used for cardiac arrest research?

Answer 1

Dogs, pigs

Question 2

Why are pigs good to use?

Answer 2

Similar resting heart rate, blood pressure and biochemistry.
Pigs have a large chest which allows for CPR and defibrillation.
Easily tailored to study specific aspects of resuscitation research.
Pigs hearts respond similarly to humans after infarction and become arrhythmogenic with reperfusion.
Similar levels and types of cholesterol.

Question 3

What are the problems with using pigS?

Answer 3

• Genetic mutation in calcium channels: predispose to malignant hyperthermia when exposed to anaesthetics.
• Farm pigs: predisposed to VF
• If young and disease free: not like our patients in CA.
• Shorter PR intervals (bundle branches/SAN different)

Question 4

Similarities to dogs?

Answer 4

Heart structure, blood vessels, anatomy and physiology.

Question 5

Differences to dogs?

Answer 5

Different HR (60-160bpm)
Dogs - if they do have heart problems more often to be: pericardial effusions, mitral valve problems and dilated cardiomyopathy rather than atherosclerosis.5

Question 6

What have animal studies taught us?

Answer 6

15:2

Question 7

What is post resuscitation blood flow characterised by?

Answer 7

Hyperaemia of cerebral, adrenal and myocardial beds.

Hypo perfusion of gut and pulmonary beds.

Question 8

Besides reduced BMR, what other suggested mechanism of hypothermia?

Answer 8

Improves contractility of failing myocardium by increasing calcium sensitivity.

Question 9

Mircrocirculatory level dysfunction post ROSC?

Answer 9

Hyperviscosity, micro thrombi, oedema, hemoconcentration?