Abstract 110

Background: The subclinical cardiac status of acutely ill children who are not suspected of having heart disease is often not assessed, but may be important in determining diagnosis, therapy and management.

Methods: During 1997-8, a convenience sample of 84 ill children without suspected myocardial injury presenting to a pediatric hospital were prospectively enrolled in a study of cardiac status. Echocardiograms, ECGs and serum cardiac troponin T (cTnT), a sensitive marker of myocardial injury, levels were obtained. Echo z-scores were determined relative to 289 normal children.

Results: All study children that had echocardiograms had subclinical cardiac abnormalities detected. For children with acute infections of non-GI (N=29) or GI (N=13) origins, hyperdynamic LV function (LV FS z-score=3.1 and 3.7 SD), normal to reduced LV contractility (stress-velocity index=0.6 and -1.0 SD), tachycardia (HR z-score=2.3 and 1.4 SD), elevated LV preload (z-score=1.7 and 3.3 SD), and reduced LV afterload (z-score=1.5 and -2.1 SD) were noted. Children presenting with chronic illness (n=4) had similar findings. This was in contrast to children with known heart disease (n=3) and other diagnoses (n=4), who had depressed LV FS (-1.9 and -0.4 SD) and contractility (-2.3 and -0.4 SD). This FS difference was significant (P=0.035). 3 patients (4.7%) had clinically insignificant pericardial effusions and 23 (30.1%) had nonspecific ST-T changes on ECG. Serum cTnT levels were elevated to acute myocardial infarction levels in 2 children (2.4%) without clinically suspected heart disease; one of whom was s/p liver transplant for Wilson's disease and the second had severe pneumonia and shock and eventually died.

Conclusion: Frequent cardiac abnormalities exist in acutely ill children, including depressed LV contractility and active myocardial injury. Although clinically occult, these abnormalities may be of significant importance, and can be detected by routine screening.