Severe hypoxic biventricular dysfunction in tetralogy of Fallot: is Blalock shunt the answer?

In a 4-year-old boy with tetralogy of Fallot, a right modified Blalock-Taussig anastomosis was created because of severe myocardial dysfunction and repeated hypercyanotic spells. Post-operatively, systemic oxygen saturation improved and also myocardial function. It is postulated that hypoxia was responsible for myocardial dysfunction previously, and its elimination has resulted in markedly improved cardiac performance.