Pediatric myocardial stunning underscores the cardiac toxicity of conventional hemodialysis treatments.

BACKGROUND AND
OBJECTIVE: In adults, hemodialysis (HD)-induced ischemia causes reversible myocardial dysfunction (myocardial stunning) that is progressive with raised attendant mortality. Children share an increased risk for death from a spectrum of uremia-related cardiovascular abnormalities but in the absence of significant classical atheromatous coronary artery disease; therefore, we elected to assess children who were on HD for the occurrence of myocardial stunning to investigate the relative importance of characteristic uremic cardiovascular abnormalities in the development of ischemic cardiac injury. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We included all single-center long-term HD patients (n = 12; range 2 to 17 yr), excluding those with structural cardiac disease. Patients underwent conventional thrice-weekly HD for 4 h using high-flux membranes. We measured regional left ventricle wall motion using serial echocardiography (before HD, during HD, and 15 min after HD). Significant stunning was defined as a 20% reduction in regional wall motion (RRWM) in two or more segments and hyperkinesis as an either >20 or >50% increase in shortening fraction (SF).
RESULTS: Eleven of 12 patients developed myocardial stunning with varying degrees of compensatory hyperkinesis in unaffected segments, maintaining left ventricular ejection fraction throughout HD. The mean segmental %SF([Overall]) and %SF([RRWM]) fell during HD (2.19 to 1.77 and 2.72 to 1.37, respectively). Intradialytic BP reduction was significantly associated with mean segmental %SF([RRWM]).
CONCLUSIONS: Children who receive conventional HD experience myocardial stunning. These data, in combination with previous adult studies of intradialytic myocardial blood flow, suggest a characteristic cardiovascular phenotype in HD patients that predisposes to significant demand ischemia.