Diagnostic value of electrocardiography and echocardiography for familial hypertrophic cardiomyopathy in genotyped children

Aim The aim of the study was to evaluate electrocardi-ography and echocardiography in the diagnosis of familial hypertrophic cardiomyopathy in children, using the genetic status as the criterion of reference. Methods and Results We analysed 35 children ( 95% confidence interval on the echocardiogram; abnormal Q waves, left ventricular hypertrophy (voltage >95th percentile), or marked ST-T changes on the electrocardiogram. Twenty-two minor electrocardiographic and echocardiographic criteria were also analysed. Using major criteria, the specificity of the electrocardiogram and echocardiogram was excellent (100% for both) but sensitivity was particularly low (38% and 50% respectively). However, when four relevant additional criteria (QRS axis, left atrium dimension, intraventricular septum/posterior wall ratio, E/A wave ratio) were taken into account, sensitivity increased to 88% and specificity remained high (95%). Conclusions (1) Familial hypertrophic cardiomyopathy was diagnosed in only ∼50% of genetically affected children by conventional electrocardiographic and/or echocardiographic criteria. (2) Relevant additional diagnostic criteria were selected so that nearly all children considered as healthy carriers of a mutation (based on conventional criteria) could be identified with excellent specificity.