ABSTRACT
BACKGROUND: Echocardiographic examinations have revealed functional cardiac abnormalities in children with chronic kidney disease. OBJECTIVE: To assess the feasibility of MRI tissue phase mapping in children and to assess regional left ventricular wall movements in children with chronic kidney disease. MATERIALS AND METHODS: Twenty pediatric patients with chronic kidney disease (before or after renal transplantation) and 12 healthy controls underwent tissue phase mapping (TPM) to quantify regional left ventricular function through myocardial long (Vz) and short-axis (Vr) velocities at all 3 levels of the left ventricle. RESULTS: Patients and controls (age: 8 years-20 years) were matched for age, height, weight, gender and heart rate. Patients had higher systolic blood pressure. No patient had left ventricular hypertrophy on MRI or diastolic dysfunction on echocardiography. Fifteen patients underwent tissue Doppler echocardiography, with normal z-scores for mitral early diastolic (VE), late diastolic (VA) and peak systolic (VS) velocities. Throughout all left ventricular levels, peak diastolic Vz and Vr (cm/s) were reduced in patients: Vzbase -10.6 ± 1.9 vs. -13.4 ± 2.0 (P < 0.0003), Vzmid -7.8 ± 1.6 vs. -11 ± 1.5 (P < 0.0001), Vzapex -3.8 ± 1.6 vs. -5.3 ± 1.6 (P = 0.01), Vrbase -4.2 ± 0.8 vs. -4.9 ± 0.7 (P = 0.01), Vrmid -4.7 ± 0.7 vs. -5.4 ± 0.7 (P = 0.01), Vrapex -4.7 ± 1.4 vs. -5.6 ± 1.1 (P = 0.05). CONCLUSION: Tissue phase mapping is feasible in children and adolescents. Children with chronic kidney disease show significantly reduced peak diastolic long- and short-axis left ventricular wall velocities, reflecting impaired early diastolic filling. Thus, tissue phase mapping detects chronic kidney disease-related functional myocardial changes before overt left ventricular hypertrophy or echocardiographic diastolic dysfunction occurs.
Subject(s)
Renal Insufficiency, Chronic/complications , Ventricular Dysfunction, Left/diagnostic imaging , Ventricular Dysfunction, Left/etiology , Adolescent , Case-Control Studies , Child , Echocardiography, Doppler , Female , Humans , Kidney Transplantation , Male , Renal Insufficiency, Chronic/surgery , Young AdultABSTRACT
BACKGROUND: Increased left ventricular mass (LVM) is an important risk marker of uremic cardiovascular disease. Calculation of LVM by echocardiography (Echo) relies on geometric assumptions and in adults on hemodialysis overestimates LVM compared to cardiac magnetic resonance (CMR). We compare both techniques in children with chronic kidney disease (CKD). METHODS: Concurrent Echo and CMR was performed in 25 children with CKD (14 after kidney transplantation) aged 8-17 years. RESULTS: Compared to normal children, CMR-LVM was increased (standard deviation score (SDS) 0.39 ± 0.8 (p = 0.03)), stroke volume and cardiac output decreased (SDS -1.76 ± 1.1, p = 0.002 and -1.11 ± 2.0, p = 0.001). CMR-LVM index but not Echo-LVMI correlated to future glomerular filtration rate (GFR) decline (r = -0.52, p = 0.01). Mean Echo-LVM was higher than CMR-LVM (117 ± 40 vs. 89 ± 29 g, p < 0.0001), with wide limits of agreement (-6.2 to 62.8 g). The Echo-CMR LVM difference increased with higher Echo-LVMI (r = 0.77, p < 0.0001). Agreement of classifying left ventricular hypertrophy was poor with Cohen's kappa of 0.08. Mean Echo and CMR-ejection fraction differed by 1.42% with wide limits of agreement (-12.6 to 15.4%). CONCLUSIONS: Echo overestimates LVM compared to CMR, especially at higher LVM. Despite this, CMR confirms increased LVM in children with CKD. Only CMR-LVMI but not Echo-LVMI correlated to future GFR decline.
