The ECG Rhythms content is currently under development and is being updated by medical professionals.
Asystole, often referred to as “flatline,” represents the complete cessation of electrical and mechanical activity in the heart. It signifies the absence of ventricular contraction and thus no cardiac output.
Analogy: “The orchestra has fallen completely silent; no music is playing.”
The ECG in asystole displays a flatline or near-flatline tracing, indicating the absence of any discernible electrical activity in the heart. There are no P waves, QRS complexes, or T waves present. This isoelectric line reflects the lack of both atrial and ventricular depolarization and repolarization. While in some rare cases, small P waves might be observed without any subsequent ventricular activity, the overall characteristic is the absence of any organized electrical rhythm. It is crucial to clinically confirm asystole as a flat line on the ECG could also be due to technical issues such as loose leads.
The clinical presentation of asystole is characterized by the signs of cardiac arrest: no pulse, no breathing, and loss of consciousness. Asystole is generally the terminal rhythm in cardiac arrest and carries an extremely poor prognosis. It can be the end result of untreated or unconverted ventricular fibrillation or pulseless electrical activity.
“Like a machine that has completely shut down, the heart shows no signs of electrical activity.”