CHAPTER 4: THE ADULT WITH REPAIRED TETRALOGY OF FALLOT

PATIENT STORY

A 29-year-old man born with tetralogy of Fallot (TOF) underwent repair when he was 9 months of age. Repair consisted of creation of a right ventriculotomy, just inferior to the pulmonary valve. Through the ventriculotomy, the surgeon closed a large ventricular septal defect (VSD) and resected muscle in the subpulmonary area of the right ventricular outflow tract (RVOT). Upon completion, the surgeon placed a large transannular patch to repair the ventriculotomy.

Approximately 14 years later, he was found to have severe pulmonary valve regurgitation complicated by severe right ventricle (RV) dilation and dysfunction and subsequently underwent pulmonary valve (PV) replacement. At the age of 29, a cardiac magnetic resonance imaging (MRI) demonstrated severe RV dilation with an RV end-diastolic volume index (RVEDVI) of 200 mL/m², mildly decreased RV function, and severe pulmonary regurgitation (PR). His pulmonary arteries were confluent without stenosis, but he had mild tricuspid regurgitation and a dilated right atrium (RA). The left ventricle (LV) ejection fraction (EF) was low-normal (50%-55%) and his aorta was mildly dilated with mild aortic valve regurgitation. From an extracardiac standpoint, he was noted to have a left superior vena cava (SVC) draining to a dilated coronary sinus and had a right aortic arch.

Shortly after his MRI, he underwent a third surgical procedure consisting of PV replacement. Following surgery, his RV did positively remodel, but unfortunately the RV size and function did not completely normalize. One month following surgery, he developed atrial flutter. He underwent electrical cardioversion and was started on anticoagulation and antiarrhythmic therapy. Unfortunately 6 months after his last surgery, while running, he suddenly collapsed and died.

CASE EXPLANATION

• TOF is one of the most common cyanotic congenital heart lesions for which infants undergo palliative repair. There is excellent long-term survival but young adults can often suffer from multiple complications.

• This case demonstrates several long-term complications that are known to occur after TOF repair including severe pulmonary regurgitation, severe RV enlargement, and the occurrence of arrhythmias that can lead to sudden cardiac death.

EPIDEMIOLOGY

• TOF is the most common form of cyanotic congenital heart disease.

• About 3.5% of all infants born with congenital heart disease have TOF which corresponds to 0.28 out of every 1000 live births.¹

• It affects males and females approximately equally.¹

• Most cases are sporadic, however, the risk of recurrence in siblings is approximately 2% to 3%, and the risk of the offspring of a patient having TOF (in the absence of 22q.11.2 deletion) is 3% to 4%.^{2, 3}

• It has been suggested that for many countries there are now more adults living with TOF than children.⁴

ETIOLOGY

• Although the majority of TOF appears to occur sporadically, its increased recurrence in some pedigrees and in consanguineous populations implies a central ...