Definition of "Cardiac arrest"

Last modified: about 1 year



Cardiac arrest (aka cardiopulmonary arrest, circulatory arrest) is a sudden stop in blood circulation due to failure of the heart to contract effectively [or at all].

Patient information

What is cardiac arrest?
It's where, because the heart is not working, blood stops flowing.

Pathophysiology
  • Arrested blood circulation prevents delivery of oxygen and glucose to the body
  • Lack of oxygen and glucose to the brain causes LOC, which then results in abnormal/absent breathing

Patient information

Uh... don't we need blood flowing to survive ?
YES!!! And what happens if blood stops flowing, is your body stops getting the oxygen and sugar it needs.

Cause
  • The causes of cardiac arrest, called the 4 H's and 4 T's, are:
    • Hypoxemia
    • Hypovolemia
    • Hypoglycemia
    • Hypo/hyperkalemia
    • Hypo/hyperthermia
    • cardiac Tamponade
    • Tension pneumothorax
    • Thromboembolism
    • Toxins/Tablets 

Patient information

So cardiac arrest is a sudden drop in blood circulation, as the heart suddenly fails to contarct effectively, or at all. What's it caused by?
The 4 H's and 4 's. So hypoxemia, hypovolemia, hypo+hyperkalemia, hypo+hyperthermia, cardiac tamponade, tension pneumothorax, thromboembolism, and tablets.

Wow. That's a big list. What do each mean?
Hypoxemia is low oxygen in blood. Hypovolemia is low blood volume. Hypo and hyperkalemia is inadequate and excessive potassium. Hypo and hyperthermia is low or high body temperature. So those re the 4 H's.

How about the 4 T's?
Cardiac tamponade is where fluid builds up around the heart. Tension pneumothorax is a collapsed lung. Thromboembolism is a blood clot. Tablet is some drug taken by the patient.

Classification

Based on whether it is Tx using defbrillation:

  • Shockable:
  • Non-shockable:
    • Asystole
    • Pulseless electrical activity (aka electromechanical dissociation), where a heart rhythm is observed on the ECG that should be producing a puse, but isn't. Normally, electrical activation of muscle cells precedes mechanical contraction of the heart, called electromechanical coupling. In PEA, there is electrical activity, but the heart either doesn't contract or there are other reasons this results in an insufficient cardiac output to generate a pulse and supply blood to the organs
Tx
  • Defibrillation, IMMEDIATELY, if a "shockable" rhythm is present
  • CPR (cardiopulmonary resuscitation), to provide circulatory support and/or to induce a "shockable" rhythm
Prognosis
  • If cardiac arrest is untreated for >5 minutes, brain injury is likely to occur → it is a medical EMERGENCY
  • In certain situations, it is potentially reversible if Tx early
  • Unexpected cardiac arrest can cause death within minutes, known as sudden cardiac death
  • For best chance of survival and neurological recovery, IMMEDIATELY Tx is important
See also

Find a practitioner

Amanda Gordon

Female Psychologist
Armchair Psychology - Edgecliff NSW
Practitioner count: 0
Sponsor a disease. And see how your proceeds help.
$1
Express interest
$10
Write text
$40
Write FAQ
$100
Snap photos
$400
Record audio
$1k
Produce video
$4k
Interview experts



Definition of Cardiac arrest | Autoprac


RSS feeds: Most recent Most viewed