Systemic hypertension complicating tetralogy of Fallot: effects of antihypertensive therapy

A 20 year old woman with tetralogy of Fallot and an associated atrial septal defect presented with severe hypertension and congestive heart failure. She had been acyanotic for several years. An acute trial of antihypertensive therapy during cardiac catheterization resulted in severe systemic oxygen desaturation and loss of consciousness. Since surgical correction, antihypertensive therapy has been well tolerated. This case demonstrates the hemodynamic importance of systemic vascular resistance in tetralogy of Fallot and the need for extreme caution if aggressive antihypertensive therapy is attempted before surgical correction.