Tricuspid regurgitation in hypoplastic left heart syndrome: mechanistic insights from 3-dimensional echocardiography and relationship with outcomes.

BACKGROUND: Our purpose was to test the following hypotheses: (1) patients with hypoplastic left heart syndrome who develop significant tricuspid regurgitation (TR) or require tricuspid valve (TV) surgery in the medium term have detectable TV abnormalities by 3-dimensional echocardiography (3DE) prestage 1 palliation and (2) TR is associated with reduced survival and increased TV intervention. METHODS AND RESULTS: Infants were prospectively studied with 3DE and 2DE prestage 1 and followed up for the end points of TR, TV surgery, transplantation, or death. From prestage 1 3DE, spatial coordinates of TV annulus and leaflets were extracted; annulus size, leaflet area, prolapse volume, tethering volume, bending angle, and papillary muscle angle were measured. TR was assessed prestage 1 and at latest follow-up. Of 70 patients, 62 (88.6%) had mild or less TR and 8 (11.4%) had moderate or greater TR prestage 1. Prestage 1 tethering volume correlated to leaflet area (r=0.736; P<0.001), annulus area (r=0.651; P<0.001), right ventricular end-diastolic area (r=0.347; P=0.003), fractional area change (r=-0.387; P<0.001), and TR grade (r=0.447; P<0.001). At follow-up, 46 (65.7%) had mild or less TR (group A) and 24 (34.3%) had moderate or greater TR (group B). Prestage 1 3DE showed greater TV tethering volume and flatter annulus in group B. Survival was better in group A. CONCLUSIONS: Increased TV tethering volume and flatter bending angle prestage 1 palliation is associated with TV failure at medium-term follow-up. Increased prestage 1 tethering is related to having larger TV annulus, larger leaflet area, larger right ventricular size, and reduced systolic function. TR progression results in increased TV intervention and decreased survival.

Echocardiographic knowledge-based reconstruction for quantification of the systemic right ventricle in young adults with repaired D-transposition of great arteries.

The systemic right ventricle (RV) in congenital heart disease is susceptible to progressive dilation and dysfunction. A 2-dimensional echocardiographic means for serial monitoring of the RV would be of great value in this clinical setting. We used 2-dimensional echocardiography with knowledge-based reconstruction (2DE-KBR) for evaluation of systemic RV. Patients with d-transposition of great arteries repaired with an atrial switch and without implanted pacemakers were prospectively recruited for same-day 2DE-KBR and cardiac magnetic resonance (CMR) imaging. RV images were acquired in various 2-dimensional imaging planes using a 3-dimensional space-localizing device attached to the imaging transducer and 3-dimensional reconstruction was performed. RV end-diastolic volume, end-systolic volume, and ejection fraction (EF) were calculated and compared to volumetric CMR analysis. Fifteen patients (7 women, 8 men, 24 ± 7 years old, weight 67 ± 12 kg) were studied. There was good agreement of 2DE-KBR and CMR measurements. Mean RV end-diastolic volume was 221 ± 39 ml with 2DE-KBR and 231 ± 35 ml with CMR (r = 0.80); mean end-systolic volume was 129 ± 35 ml with KBR and 132 ± 30 ml with CMR (r = 0.82), and EF was 42 ± 10% with KBR and 43 ± 7% with CMR (r = 0.86). For 2DE-KBR mean interobserver variabilities were 4.6%, 2.6%, and 4.3%; intraobserver variabilities were 3.2%, 3.1%, and 2.3%, respectively, for end-diastolic volume, end-systolic volume, and EF. In conclusion, this study demonstrates the clinical feasibility of quantifying systemic RV volumes and function using 2DE-KBR in adolescents and young adults with repaired d-transposition of great arteries and good agreement of measurements with CMR.

Serial assessment of right ventricular volume and function in surgically palliated hypoplastic left heart syndrome using real-time transthoracic three-dimensional echocardiography.

BACKGROUND: Right ventricular (RV) failure is a major cause of morbidity and mortality in patients with hypoplastic left heart syndrome (HLHS), but the longitudinal course of RV volumes through staged palliation (SP) has not been previously investigated. The aim of this study was to evaluate RV volume and function longitudinally through SP of HLHS using real-time three-dimensional echocardiography. METHODS: A total of 18 subjects with HLHS were prospectively studied at four time points from diagnosis through stage 2 (SP2). Real-time three-dimensional echocardiographic full-volume data sets were acquired in high-frame rate mode with electrocardiographic gating. Volumetric and functional analyses were performed using a semiautomatic contour detection algorithm. Eighteen age-matched and sex-matched normal infants (aged 0-6 months) were studied at comparable time points as controls. RESULTS: Presurgical examinations (pre-stage 1 [SP1]; n = 18) were performed at a mean age of 4 days, post-SP1 examinations (n = 17) at a mean age of 20 days, pre-SP2 examinations (n = 14) at a mean age of 4.6 months, and post-SP2 examinations (n = 14) at a mean age of 5.5 months, constituting a total of 63 examinations. The mean values of RV end-diastolic volume indexed to body surface area (EDVi) at the four time points were 87 ± 30, 104 ± 39, 112 ± 34, and 102 ± 35 mL/m(2), respectively. There was an increase in EDVi (P = .024) from pre-SP1 to post-SP1 but no significant change between post-SP1 and pre-SP2. The decrease in EDVi after SP2 did not reach statistical significance. Mean RV ejection fractions (EFs) were 50 ± 5%, 45 ± 5%, 46 ± 5%, and 38 ± 4%, respectively. There was a trend toward decreasing EF throughout SP, with statistically significant decreases from pre-SP1 to post-SP1 (P = .003) and from pre-SP2 to post-SP2 (P < .001). In normal infants, the mean RV EDVi was 50 ± 10 mL/m(2) (approximately half that of patients with HLHS), and the mean EF was 51 ± 3%. There was good interobserver agreement for EDVi, end-systolic volume indexed to body surface area, and EF. CONCLUSIONS: Real-time three-dimensional echocardiography is a reproducible means for evaluating RV volumes and EFs in patients with HLHS. Indexed RV diastolic volume remains stable to slightly increased, and RV EF deteriorates as the first two stages of surgical palliation are accomplished. The findings of this study highlight the adverse physiology of HLHS, which deteriorates even among early survivors despite SP.