Mechanisms of tricuspid valve regurgitation in hypoplastic left heart syndrome: a case-matched echocardiographicsurgical comparison study

The multifactorial mechanisms of tricuspid valve (TV) insufficiency in patients with hypoplastic left heart syndrome (HLHS) include structural anomalies of TV leaflets and ventricular dilatation. We hypothesized that 2-D echocardiography underestimates the importance of TV structural abnormalities, whereas surgical assessment underestimates the importance of motion abnormalities, and compared echocardiographic assessment with surgical description. Two independent experts retrospectively reviewed echocardiograms of all patients who had staged single-ventricular palliation and TV repair during January 1998December 2008, and compared with case-matched controls who did not require TV repair. Primary and secondary mechanisms of TV insufficiency were categorized, and surgical findings ascertained from operation records. There were 32 patients with a median age of 5.9 months (0.3140) and 32 matched controls. On echocardiographic review, an abnormality of at least one leaflet was noted in every patient (100) vs. in only 14 controls 14 (44) (P 0.001). Leaflet prolapse was described in 22 (69), and the restriction of a leaflet in 20 (69). Agreement between the experts was excellent ( 0.640.88). On surgical inspection, annular dilatation was found in 17 (53), and leaflet dysplasia in 14 (44). Agreement between echocardiographic and surgical assessment was poor ( 0.6). Important structural abnormalities are common in patients with HLHS and TV insufficiency, some readily identified by 2-D echocardiography. However, there are significant discrepancies between echocardiographic and surgical findings. Echocardiographic assessment is sensitive to detect leaflet motion abnormalities, but not leaflet structural abnormalities. Both echocardiographers and surgeons should be aware of these limitations when planning surgical interventions.