Tetralogy of Fallot: Origins, Management and Outcomes

Tetraology of Fallot (TOF) is the most common of the cyanotic congenital heart diseases. It is characterized by four anatomical lesions all of which have a spectrum of severity. Clinically the presentation of the neonate depends on the degree of Right Ventricular Outflow Tract (RVOT) obstruction and the patency of the ductus arteriosus with common symptoms including paroxysms of irritability, diaphoresis, hyper cyanotic spells and heart failure. Physicians currently use a multitude of investigations in order to demonstrate the complex physiology of TOF including sonography (in utero), Doppler echocardiography, cardiac catheterization, Multidetector CT (MDCT) and MRI. When used in combination these allow for planned surgical management of this otherwise life limiting condition which can be technically challenging due to variable anatomy. Currently patients should have curative surgery between 3-6 months with surgical approaches including VSD closure through a transaterial-transpulmonary approach and Transannular Patch (TAP) placement to limit RVOT. Currently, 97% TOF patients can expect to survive one year however they require very close follow up with cohort studies revealing high risks of ventricular arrhythmia and sudden cardiac death.