Echocardiographic Detection of Heart Transplant Graft Dysfunction: A New Twist on an Old Theme.

Abstract

It would have seemed that the problem is relatively simple: graft rejection or coronary artery disease after cardiac transplantation induces edema, inflammation, myocyte damage, necrosis, ischemia, and sometimes fibrosis, resulting in ventricular systolic and diastolic dysfunction. These should be detectable by echocardiography; yet, the quest for a sufficiently sensitive, specific, and conclusive echo marker of orthotopic heart transplant (OHT) graft dysfunction has been elusive. Consequently, children with OHT may undergo repeated myocardial biopsies and coronary angiography to diagnose graft rejection and coronary artery disease. Although these procedures are associated with low risk overall, they are not without complications and entail considerable discomfort, especially in children, and may be performed repeatedly over the course of many years. Thus, it would be of substantial benefit to have an echo measure that can be applied simply and repeatedly to diagnose or exclude acute or chronic graft dysfunction. See Article by Nawaytou et al Multiple echo measures have been proposed to address this need. These have included a change in chamber dimensions or wall thickness to indicate ventricular remodeling or edema, ejection phase measures, such as ejection fraction or fractional shortening, development of pericardial effusion, and more recently tissue Doppler and myocardial deformation to more directly assess impaired myocardial function, which underlies graft dysfunction. Impaired myocardial relaxation and increased stiffness induced by graft rejection or coronary artery disease may precede systolic dysfunction.1 Therefore, diastolic measures, such as the E / A ratio, tissue Doppler e ′, and E / e ′ ratio, may be early markers of graft dysfunction.2 Interestingly, some pediatric studies have found right ventricular (RV) parameters to be more sensitive than left ventricular (LV) parameters.3 In addition, our group and others have used provocative testing in children with OHT to detect wall motion abnormalities that may herald coronary …