The most important and best described clinical context for pulmonary regurgitation occurs in patients with repaired Tetralogy of Fallot. The first section deals briefly with pulmonary regurgitation in other situations; the remainder of the article deals with tetralogy of Fallot.

PULMONARY REGURGITATION IN CONDITIONS OTHER THAN TETRALOGY OF FALLOT

Isolated pulmonary regurgitation, in an otherwise normal heart, is well tolerated for decades. However, in a meta-analysis reported in the literature, 29% of patients had developed symptoms within 40 years.¹ Many patients with a right ventricle to pulmonary artery conduit develop a mixture of obstruction and regurgitation across the conduit. However, some of these patients have regurgitation as the dominant lesion, and feature in pulmonary valve replacement series.^2,3

Even valvar pulmonary stenosis treated surgically or by balloon dilatation can lead to significant pulmonary regurgitation requiring valve replacement. Fifty­seven per cent of patients had moderate to severe pulmonary regurgitation in a balloon dilatation series,^w1 and in a surgical pulmonary valvotomy series 9% of patients required pulmonary valve replacement.^w2

In pulmonary regurgitation secondary to pulmonary hypertension, the clinical picture is dominated by the primary lung disease or the high pulmonary vascular resistance rather than the volume load.

Severe acute pulmonary regurgitation driven by a large duct can occur in neonatal Ebstein’s anomaly,⁴ or following balloon dilation of critical pulmonary stenosis or perforation of valvar pulmonary atresia. If this torrential pulmonary regurgitation is accompanied by tricuspid regurgitation, a circular shunt may occur, due to right­to­left shunting across the atrial communication and left­to­right shunting at the duct resulting in poor systemic blood flow. Prostaglandins are stopped and in the most unstable patients, urgent duct ligation may be required. Attempts to decrease pulmonary regurgitation by pulmonary vasodilatation (increased ventilation, oxygen, nitric oxide) may be more successful if the tricuspid valve is competent.

PULMONARY REGURGITATION IN REPAIRED TETRALOGY OF FALLOT

Repair of tetralogy of Fallot is one …