Chronotropic incompetence in paediatric heart transplant recipients with prior congenital heart disease.

BACKGROUND: Cardiopulmonary exercise testing has been used to measure functional capacity in children who have undergone a heart transplant. Cardiopulmonary exercise testing results have not been compared between children transplanted for a primary diagnosis of CHD and those with a primary diagnosis of cardiomyopathy despite differences in outcomes. This study is aimed to compare cardiopulmonary exercise testing performance between these two groups. METHODS: Patients who underwent heart transplant with subsequent cardiopulmonary exercise testing at least 6 months after transplant at our institution were identified. They were then divided into two groups based on primary cardiac diagnosis: CHD or cardiomyopathy. Patient characteristics, echocardiograms, cardiac catheterisations, outcomes, and cardiopulmonary exercise test results were compared between the two groups. RESULTS: From the total of 35 patients, 15 (43%) had CHD and 20 (57%) had cardiomyopathy. Age at transplant, kidney disease, lung disease, previous rejection, coronary vasculopathy, catheterisation, and echocardiographic data were similar between the groups. Mean time from transplant to cardiopulmonary exercise testing, exercise duration, and maximum oxygen consumption were similar in both groups. There was a difference in heart rate response with CHD heart rate response of 63 beats per minute compared to cardiomyopathy group of 78 (p = 0.028). Patients with CHD had more chronotropic incompetence than those with cardiomyopathy (p = 0.036). CONCLUSION: Primary diagnosis of CHD is associated with abnormal heart rate response and more chronotropic incompetence compared to those transplanted for cardiomyopathy.

Monocusp valve placement in children with tetralogy of Fallot undergoing repair with transannular patch: A functioning pulmonary valve does not improve immediate postsurgical outcomes.

INTRODUCTION: In patients with tetralogy of Fallot (TOF), use of transannular patch (TAP) may be required in order to relieve significant right ventricular outflow tract obstruction, subsequently resulting in pulmonary insufficiency (PI). The monocusp valve has been used to temporarily reduce insufficiency in hopes to improve short and midterm outcomes. The purpose of this study was to assess for potential benefits of the monocusp valve in this subset of patients. DESIGN: Between 2005 and 2016, 119 patients with TOF with pulmonary stenosis who underwent repair with TAP were analyzed, 43 (36.1%) had a monocusp valve placed. Immediate outcomes were assessed by postoperative echocardiograms, ICU data including time to extubation, chest tube duration, reintervention, length of stay, and mortality. RESULTS: Median age of repair was similar for monocusp group at 143.5 days and nonmonocusp at 137.0 days (P = .93). Peak preoperative right ventricular outflow tract obstruction was higher in the monocusp group (80 mm Hg vs. 70 mm Hg, P ≤ .01). Patients who had monocusp placed had longer bypass time. There was less PI for monocusp group immediately after repair and at discharge (P ≤ .01). There was no difference in days of intubation, chest tube duration, length of hospitalization, reintervention rates, or mortality. CONCLUSION: Decreasing the degree of PI with a monocusp valve in patients undergoing repair for TOF repair with TAP does not improve clinical outcomes in the immediate postoperative period.