Elevated ejection-phase myocardial wall stress in children with chronic kidney disease.

Myocardial wall stress (MWS) is thought to be the mechanical stimulus to ventricular hypertrophy. The objective of this study was to examine whether MWS is elevated in children with chronic kidney disease (CKD) who are at high risk of developing adverse cardiovascular events related to left ventricular (LV) hypertrophy. MWS, a function of left ventricular pressure, myocardial wall volume, and cavity volume, was obtained using carotid tonometry to estimate ventricular pressure and 2-dimensional transthoracic echocardiographic wall-tracking to obtain LV cavity and wall volumes. Ninety-two children (50 boys) aged 11.2±3.2 (mean±SD) years, including healthy controls (n=16), and those with CKD disease divided into 3 groups according to estimated glomerular filtration rate (mL/min per 1.73 m2) >90 (CKD 1, n=26), 60 to 90(CKD 2, n=23), and <60 (CKD≥3, n=27) were studied. There was no significant difference in age, height, weight, central or peripheral blood pressure, LV mass, or mass index in the 4 study groups. By contrast, peak, mean, and end-systolic MWS were higher in children with CKD and increased across stages of CKD (peak MWS, 338.8±18.5 and 397.5±14.3 s/cm2 in controls and CKD≥3, respectively; P=0.01). Higher systolic MWS was explained by a form of LV dysfunction whereby dynamic values of the ratio of wall volume/cavity size during systole were lower in children with CKD than in those without (P=0.001). Children with CKD exhibit blood pressure–independent LV dysfunction which results in increased systolic MWS and which may predispose to LV hypertrophy in later life.