Basic pathophysiology of sudden cardiac
arrest
Tereza Prokopová
Zápatí prezentace2
Learning objectives
̶ Student will learn what are the causes of primary circulatory
arrest.
̶ Student will learn what are the causes of secondary circulatory
arrest.
̶ Student will learn the basic facts about the role of oxygen in the
sudden cardiac arrest.
Basic pathophysiology of SCA3
What is essential for human?
Basic pathophysiology of SCA4
Cycle of oxygen
̶ Lungs oxygenate blood
̶ Oxygenated blood goes to heart
̶ Heart pumps oxygenated blood to whole body
̶ Deoxygenated blood goes to heart through veins
̶ Heart pumps deoxygenated blood to lungs
IDEAL STATE
Basic pathophysiology of SCA5
SCA
̶ Sudden cardiac arrest
̶ Sudden interruption in blood flow in systemic bloodstream
̶ Heart does not pump blood
̶ Leads to death without help
Basic pathophysiology of SCA6
Types of cardiac arrest
̶ Primary (Cardiac)
̶ Secondary (Not cardiac)
Basic pathophysiology of SCA7
Primary SCA
̶ Problem with bloodstream
̶ Heart failure (heart attack, arrhythmias,…)
→ heart cannot pump blood
̶ Insufficient intravascular volume (bleeding,…)
→ nothing to pump
̶ → both cases lead to SCA
Basic pathophysiology of SCA8
Secondary SCA
̶ Problem with ventilation
̶ For example: suffocation, drowning, asphyxia
̶ Heart pumps blood to lungs, but blood is not oxygenated over
there
̶ Level of oxygen in blood is dropping
̶ Not enough oxygen for heart
̶ Leads to heart failure
̶ Heart stops → SCA
Basic pathophysiology of SCA9
Secondary SCA – what follows?
̶ More often in childhood
̶ The blood oxygen level is lower than in case of primary SCA in
time when heart stops
̶ Higher importance of rescue breaths
̶ Higher emphasis on rescue breaths in child CPR algorithm
̶ Do not palpate the pulse in BLS
̶ If the victim is not breathing, the heart stops working very soon
Basic pathophysiology of SCA10
What is the short term goal during CPR?
̶ Provide heart with enough oxygen → chance for restoration of
spontaneous circulation (ROSC)
̶ Blood oxygenation – rescue breaths
̶ Oxygen distribution – chest compression
Basic pathophysiology of SCA11
What is the long term goal during CPR?
̶ Oxygen for brain - good quality of life
Zápatí prezentace12
Learning outcomes
̶ Student knows the differences between primary and secondary
cardiac arrest.
̶ Student is able to explain the importance of uninterrupted chest
compressions.
Basic pathophysiology of SCA13
Thank you for your attention
Basic pathophysiology of SCA14
Sources
̶ www.erc.edu
̶ Pictures:
̶ https://rebelem.com/epinephrine-in-out-of-hospital-cardiac-arrest-poll/
̶ www.erc.edu
Simulation Centre, Faculty of Medicine, Masaryk University
2020