514: Donor (+)/recipient (-) EBV mismatch leads to a high incidence of post-transplant lymphoproliferative disorder in pediatric lung transplant recipients

Abstract

22.9 5.9, 19.8 3.7 and 18.5 3.0 in TX, Fontan and healthy groups, p 0.01) and baseline HR (107 11, 88 14 and 90 17 beats/min, p 0.001) compared to control groups. Both TX and Fontan patients had similar degree of chronotropic impairment (peak HR 158 19 (76 9%predicted), 164 17 (79 8%predicted) and 196 10 beats/min (95 5% predicted) in TX, Fontan and healthy groups). However, exercise duration was significantly lower in TX patients (9.1 2.0, 10.7 2.5 and 14.4 2.3 min, p 0.01). HR recovery was markedly slower in TX patients compared to control groups at both 1 minute (5 7 beats (3 4%), 23 10 beats (15 7%) and 39 15 beats (20 7%), p 0.001) and 3 minutes (20 13 beats (13 8%), 50 15 beats (30 9%) and 80 15 beats (41 7%), p 0.001) following peak exercise. In multivariable linear regression models, patient group and BMI were predictors of HR recovery at 1 and 3 minutes; exercise duration was not. Conclusions: Heart rate recovery following maximal exercise is markedly slower in children one-year following heart transplant compared to age-matched controls. Whether chronotropic response and HR recovery improve with time due to autonomic re-innervation is unknown and requires serial studies in these patients.