Cause
Possible underlying causes include the Hs and Ts.
- Hypovolemia
- Hypoxia
- Hydrogen ions (acidosis)
- Hypothermia
- Hyperkalemia or hypokalemia
- Hypoglycemia
- Tablets or toxins (drug overdose)
- Cardiac Tamponade
- Tension pneumothorax
- Thrombosis (myocardial infarction)
- Thrombosis (pulmonary embolism)
- Trauma (hypovolemia from blood loss)
While the heart is asystolic, there is no blood flow to the brain unless CPR or internal cardiac massage (when the chest is opened and the heart is manually compressed) is performed, and even then it is a small amount. After many emergency treatments have been applied but the heart is still unresponsive, it is time to consider pronouncing the patient dead. Even in the rare case that a rhythm reappears, if asystole has persisted for fifteen minutes or more the brain will have been deprived of oxygen long enough to cause brain death.
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ECG lead showing Asystole (Flatline)
Read more about this topic: Asystole