The normal electrical conduction of the heart is from the atria to the ventricles, and there is only one pathway. In contrast, in preexcitation syndrome, there is one or more abnormal channels between the congenital atria and ventricles, which can cause some of the ventricular muscles to contract with premature excitation, and the patient has no organic heart disease. type B preexcitation means that this bypass is located in the right heart, which is the electrocardiographic subtype of preexcitation syndrome and is not commonly used in clinical practice nowadays. Tachycardia occurs when the preexcited bypass short-circuits the normal atrial to ventricular conduction pathway, forming a foldback loop. Patients often present with sudden panic attacks with no apparent cause and a heart rate of up to 250-300 beats per minute. The disease is congenitally caused and can be cured after bypass radiofrequency ablation, which has a cure rate of more than 95%, but recurrence can occur in a minority of patients.