Pulmonary Valve Stenosis

Pulmonary valve stenosis is usually a congenital narrowing that obstructs blood leaving the right ventricle for the pulmonary artery. The right ventricle must generate extra pressure to push blood through the narrowed outlet. Over time, that pressure load causes right-ventricular hypertrophy and can impair right-ventricular filling and function. “Pulmonary stenosis” is sometimes used loosely, but the obstruction may occur at several levels of the right ventricular outflow tract: - Valvular: at the pulmonary valve; this is the most common form and is often amenable to balloon valvuloplasty. - Subvalvular or infundibular: in the muscular outflow tract below the valve. - Supravalvular: above the valve in the main pulmonary artery. - Branch pulmonary artery stenosis: in one or both pulmonary artery branches. The level matters because a balloon across the pulmonary valve can split fused valve commissures, but it cannot correct an obstruction below, above, or beyond the valve. Treating all right ventricular outflow tract obstruction as “valve stenosis” can lead to the wrong procedure. A doming valve with fused commissures usually responds well to balloon dilation. A dysplastic valve is...