Tissue Doppler Echo Imaging of Heart Function After Transplant

Heart transplantation is the only hope for children with end stage heart disease. Eventually cardiac deterioration occurs and leads to death or re-transplantation. Our understanding of the pathophysiology of cardiac dysfunction in these children is incomplete. The time course of the dysfunction process either in the RV and/or the LV, systole or diastole has never been studied in children. No meaningful TSI quantitation has ever been performed in a large pediatric OHT patient population. The long-term goal of this study will be the detection of functional myocardial changes associated with known stages post heart transplantation using TDI and TSI. These achievements impact the survival and quality of life of children after cardiac transplantation.

Research Design and Methods

All subjects who are treated in the transplant clinic will be approached for possible participation into the study. These patients will include newly transplanted (OHT) patients as well as patients who underwent OHT prior to the enrollment year. The following procedures will occur at each study visit:

Echocardiographic assessment Standard 2-dimensional, M-mode, and Doppler or 3-dimensional echocardiography evaluation will be performed. We will assess cardiac function using left ventricular shortening (SF) and ejection fractions (EF). The EF will be calculated using both M-Mode and by Simpson’s rule. We will also perform tissue synchronization imaging (TSI) and tissue Doppler imaging (TDI) using the GE Vivid 7 echocardiographic system. Both TSI and TDI will assist investigators in assessing mechanical synchrony. In newly transplanted patients, these echocardiographic assessments will occur during the first 5 days to serially measure ventricular synchrony during the acute post-operative period. For older transplant patients and for new transplant patients greater than five days out from transplantation, echocardiographic studies will occur at all follow-up clinic visits as determined by physician preference.

Clinical assessment Clinical evaluation will be performed during all follow-up visits in order to track unrecognized complications or adverse events. As is standard, all patients undergoing transplantation follow-up will have an electrocardiogram (EKG) performed to assess rhythm.