A rare association of tetralogy of Fallot and hypertrophic cardiomyopathy

Tetralogy of Fallot (TOF) is the most common form of cyanotic congenital heart disease. It is often associated with other congenital cardiac or non-cardiac defects. However, its association with hypertrophic cardiomyopathy (HCM) is rarely reported. We reported two cases. The first case is a full-term girl receiving modified Blalock-Taussig shunt creation and the second case is an 8-month old boy receiving total correction for TOF. Although they tolerated the operation well, both of them developed congestive heart failure and died of malignant cardiac arrhythmia several months after the operation. We made a literature review and only 11 case reports were found. There is currently no treatment guideline for this group of patients. From our limited experience and case reports, the physiology of HCM and TOF should both be taken into consideration when managing these patients. Close echocardiography follow-up with early myectomy and preventive implantation of implantable cardioverter-defibrillator may be beneficial for them.