Retrospective Pulmonary Valve Replacement Imaging

Congenital heart defects having a component of pulmonary stenosis (narrowing) are often palliated in childhood by disrupting the pulmonary valve. This arrangement can provide an excellent quality of life as these children grow and enter young adulthood. Unfortunately, the pulmonary insufficiency that is created by disrupting the pulmonary valve results in volume overload of the right heart. This may eventually lead to right ventricular dilation and irreversible right heart failure. In addition, volume load of the right heart may affect the inter-ventricular septum and left heart function as well. Placement of a competent pulmonary valve at a subsequent operation, hopefully at a time without the replacement valve size constraints present at the initial operation, is a means to eliminate the volume overload and prevent these further sequelae.

Unfortunately, the optimal timing for subsequent pulmonary valve replacement is controversial. One of the currently used indications for valve replacement includes a right ventricular to left ventricular volume ratio greater than two. However, determining the boundaries of the right ventricle by echocardiography and magnetic resonance imaging is difficult in the absence of a pulmonary valve. The boundaries are determined by an arbitrary estimation of where the pulmonary valve should be. Other potential indicators for pulmonary valve replacement may be right ventricular area and right ventricular strain, determined by echocardiography. These measurements are not affected by the absence of the pulmonary valve. They may provide better markers for impending right ventricular failure and a simpler means to follow serial improvement following valve replacement.

While the emphasis after pulmonary valve disruption typically lies on the right ventricle, there is evidence that the left ventricle may become impaired as well. Volume load on the right ventricle causes bowing of the inter-ventricular septum and affects left ventricular function. Echocardiographic imaging of the left ventricle may also be important to follow serial improvement of the left heart following pulmonary valve replacement.

All charts reviewed will be of patients who had their surgery at Children's Healthcare of Atlanta or Emory University Hospital between January 1, 1994 and December 31, 2006. We will review approximately 125 patients' charts for patients between the ages of 1 and 65 years of age who have required pulmonary valve replacement.