Asystole, commonly known as flatline, is a state of no cardiac electrical activity.
Therefore no contractions of the myocardium and no cardiac output or blood flow.
This is one of the conditions that may be used for recognition of life extinct (ROLE), but it can be treated by administering (CPR) combined with an intravenous vasopressor such as epinephrine (adrenaline).
Sometimes an underlying reversible cause can be detected and treated. The use of ‘H’s and T’s’ provide a mnemonic help remember the major contributing factors to Pulseless electrical activity or PEA,such as Asystole, Ventricular Fibrillation, and Ventricular Tachycardia.
The H’s include:
Hypovolemia, Hypoxia, Hydrogen ion (acidosis), Hyper-/hypokalemia, Hypothermia.
The T’s include:
Toxins, Tamponade(cardiac),Tension pneumothorax, Thrombosis (coronary and pulmonary).
Survival rates in a cardiac arrest patient with asystole are much lower than a patient with a rhythm amenable to defibrillation; asystole is itself not a “shockable” rhythm. Out-of-hospital survival rates (even with emergency intervention) are less than 2 percent.