The causes of syncope in Tetralogy of Fallot generally involve episodic hypoxia attacks, which are more common in infants. Triggers include breastfeeding, crying, emotional excitement, anemia, and infections. The symptoms manifest as episodic breathing difficulties, and severe cases can suddenly lead to syncope with convulsions or even death. The underlying reason is the narrowing of the pulmonary artery infundibulum accompanied by muscular spasms, causing obstruction of the pulmonary artery and intensifying cerebral hypoxia. Older children may complain of headaches and dizziness.