Tetralogy of Fallot

Tetralogy of Fallot is a congenital heart defect which is classically understood to involve four anatomical abnormalities (although only three of them are always present). It is the most common cyanotic heart defect, and the most common cause of blue baby syndrome.

                           Diagram of a healthy heart and one suffering from tetralogy of Fallot



Tetralogy is:
1. Infundibular PS
2. RVH
3. Overriding Aorta (it over rides VSD)
4. Perimembranous VSD


Cause: because of improper rotation of Truncus Arteriosus over heart(bulbous cordis)
Can also be genetic: Mutation..Catch 22
                                  As a part of: a. Poland Syndrome
                                                      b. Goldenhar syndrome

C/f : 1. Central cyanosis
        2. Polycythemia
        3. Clubbing
        4. Iron defficiency
        5. Cynotic spells/squating episodes

Complications: 1. Brain abcess
                          2. Thromboembolic phenomenon

On Examination: 1.Single S2
                          2. Normal Size Heart

Chest X-ray : Boot shape heart (coer en sabot)

ECG : RVH and P-Pulmonale

T/t: For Cynotic spells: 1. Put in knee chest position
                                   2. Give O2
                                   3. Na Bicarbonate
                                   4. Morphine
                                   5. Increase systemic vascular resistance by Phenylephrine/Ketamine
                                   6. Decrease dynamic spasm by Propranolol.

Palliative shunt: MC is Blalock Tausig Shunt (Pulmonary artery to Subclavian artery)

Definitive Treatment: at 3-6 months age

CHF is rare in TOF but if TOF is associated with anaemia or myocarditis then there can be CHF with it.