Differential diagnosis between left ventricular hypertrophy and cardiomyopathy in childhood.

The sensitivity and specificity of the electrocardiogram for the diagnosis of left ventricular hypertrophy of different etiologies are described. The sensitivity of the electrocardiogram for detecting left ventricular pressure overload is substantially lower (<35%) than the sensitivity for detecting evidence of a cardiomyopathy (55% to around 87%). Attention is drawn to the finding that in many differing etiologies of left ventricular hypertrophy ST-T-wave changes commonly referred to as "strain"-pattern are a harbinger of an increased risk of malignant cardiac arrhythmias and sudden death. In the most common pediatric cause of sudden death, hypertrophic cardiomyopathy, a described ECG risk score, which scores both voltage and repolarization abnormalities, is the most powerful predictor hitherto described for predicting the risk of sudden death in this diagnosis. A point score over 5 points gives a relative risk for sudden death of 24.3 with a sensitivity of 96% and a specificity of 78% in childhood.