There are clear differences between ventricular fibrillation and atrial fibrillation in terms of pathology, ECG presentation, symptoms, treatment, and prognosis. Ventricular fibrillation is a malignant arrhythmia that often occurs prior to cardiac arrest and carries a very high risk of sudden death if not defibrillated in a timely manner. The ECG manifests as irregular waves without any regularity, similar to irregular waves, with no P or QRS waves to be found, and the patient will show loss of consciousness, respiratory arrest, and loss of arterial fluctuations, requiring immediate defibrillation and cardiopulmonary cerebral resuscitation. Atrial fibrillation is a common arrhythmia, most of which is due to multiple ectopic pacing points in the atria. The electrocardiographic manifestation is the disappearance of P waves, which are replaced by small f waves with absolutely unequal RR spacing and unequal R wave amplitude. Treatment can choose radiofrequency ablation surgery or electrical resuscitation, or drug resuscitation, once the formation of persistent atrial fibrillation to prevent embolism, selective application of anticoagulant drugs.