Junctional tachycardia is a type of supraventricular tachycardia, an ectopic rhythm caused by increased autoregulation or triggered ectopic potential discharge in the tissue of the atrioventricular junctional zone. When tachycardia does not occur, there are no uncomfortable symptoms and no abnormalities in the electrocardiogram. When the heart rate is greater than 160 beats/min during an attack, there will be manifestations of cerebral ischemia such as dizziness and weakness. Junctional tachycardia is commonly caused by myocardial ischemia, myocarditis, inferior wall myocardial infarction, acute rheumatic heart disease, digitalis toxicity, etc. When patients develop junctional tachycardia, electrocardiogram, cardiac ultrasound, liver and kidney function, and thyroid function should be tested to clarify the cause, and medication or even electrical cardioversion should be given to convert the heart rhythm to sinus rhythm. In case of recurrent junctional tachycardia, radiofrequency ablation can be done for complete treatment.