Fatal arrhythmias mainly refer to paroxysmal ventricular tachycardia and 3rd degree AV block. Although supraventricular tachycardia is generally not fatal, it is common in clinical practice and can be dangerous when combined with pre-excitation syndrome and not properly treated. In the light of clinical practice, here we will focus on home first aid and self-help for ventricular tachycardia and supraventricular tachycardia. (A) paroxysmal ventricular tachycardia 1, hit the patient’s precordial area: the patient at home or outside the hospital “ventricular tachycardia”, the witness can immediately tap the precordial area several times, using the impact of the low energy current of 10 to 35 joules to make the “ventricular tachycardia” and just occurred The “ventricular fibrillation” to restore the normal rhythm; 2, coughing action self-help: the occurrence of fatal ventricular tachycardia can be coughing 4 to 5 times in a row to save themselves. (2) Paroxysmal supraventricular tachycardia In “supraventricular tachycardia”, the stimulation of vagal excitation can make the tachycardia abruptly suspended in some patients, and the following methods can be tried for self-help at home: 1. Try to make the head back or torso forward bend; 4. Blow the balloon; 5. Inhale deeply and then exhale deeply.