Insights from 3D Echocardiography in Hypoplastic Left Heart Syndrome Patients Undergoing TV Repair.

BACKGROUND: Tricuspid regurgitation (TR) in hypoplastic left heart syndrome (HLHS) is associated with morbidity and mortality. TR mechanisms and the impact of tricuspid valve repair (TVR) are unclear. We examined HLHS TR mechanisms, TVR's impact on tricuspid valve (TV), and features of poor TVR durability. METHODS: We retrospectively compared 35 HLHS TVR cases and 35 age/stage-matched HLHS controls who do not undergo TVR. Pre-operative 3-dimensional echocardiography (3DE) assessed overall TV morphology (prolapse, normal, tethered), leaflet morphology, vena contracta area, and TR location. Two-dimensional echocardiography measured TV annulus diameter, RV fractional area change (RVFAC), sphericity, and TR grade at three time points (pre-op, early post-op, and latest follow-up). RESULTS: Pre-op, TVR group, and controls had no difference in age, RV function or shape, or TV dimension. TVR group most commonly had anterior leaflet prolapse followed by septal leaflet prolapse or tethering. TR jet arises centrally (63%) and anterior septally (26%). Posterior annuloplasty (69%), commissuroplasty (37%), and leaflet repair (37%) were surgical techniques commonly performed. At early post-op, TR grade and TV annulus decreased. At latest follow-up, TV annulus remained reduced; however, 50% had significant TR. 25% required TV reoperation. Larger vena contracta at TVR was associated with significant TR. CONCLUSION: HLHS patients undergoing TVR had more anterior leaflet prolapse and central TR. While TVR initially reduces annular size and TR grade, 50% redevelop significant TR despite maintained annular reduction. The association of greater TR severity prior to repair with post-op recurrence raises the consideration for earlier repair of TR in HLHS patients.

Dynamic Systolic Changes in Tricuspid Regurgitation Vena Contracta Size and Proximal Isovelocity Surface Area in Hypoplastic Left Heart Syndrome: A Three-Dimensional Color Doppler Echocardiographic Study.

BACKGROUND: The aims of this study were to investigate the dynamic changes in the vena contracta (VC) and proximal isovelocity surface area (PISA) through systole in patients with hypoplastic left heart syndrome and tricuspid regurgitation and to identify the stage of systole (early, mid, or late) in which VC and PISA radius are optimal. METHODS: Twenty-eight patients with hypoplastic left heart syndrome were prospectively studied using continuous two-dimensional (2D) and three-dimensional (3D) echocardiography. Two-dimensional VC width, 3D VC area, and PISA radii (2D and 3D) were measured frame by frame throughout systole. The maximal 2D VC width, 3D VC area, and PISA radii in the first, middle, and last thirds of systole were compared, and correlations were explored with 3D tricuspid annular areas, right atrial volumes, and right ventricular volumes. RESULTS: In all, 35 data sets that met inclusion criteria were analyzed. On frame-by-frame analysis, maximal 2D VC width and 3D VC area were found in the first third of systole in 17% and 20% of studies, in the second third in 34% and 31%, and in the final third in 49% and 49%. Similarly, the maximal 2D and 3D PISA radii were found in the first third of systole in 26% and 17% of studies, in the second third in 28% and 34%, and in the final third in 46% and 49%. CONCLUSIONS: In hypoplastic left heart syndrome, detailed temporal analysis of tricuspid regurgitation-associated VC and PISA by 2D and 3D echocardiography reveals no reliable pattern predicting when in systole these parameters peak. Frame-by-frame measurement is necessary for identification of maximal VC and PISA radius on 2D and 3D color Doppler echocardiography because the severity of tricuspid regurgitation could be underestimated because of temporal variability in VC and PISA.

Tricuspid Regurgitation in Hypoplastic Left Heart Syndrome: Three-Dimensional Echocardiography Provides Additional Information in Describing Jet Location.

BACKGROUND: Twenty-five percent of patients with hypoplastic left heart syndrome (HLHS) require tricuspid valve (TV) repair. The location of tricuspid regurgitation (TR) is important in determining the type of repair performed. Studies using three-dimensional echocardiography (3DE) have reported a high incidence of error on two-dimensional echocardiography (2DE) for the identification of TV leaflets. The aim of this study was to compare assessment of TR on 3DE and 2DE in patients with HLHS (jet location, TR grade, and reproducibility). METHODS: A retrospective, single-center review was performed. Fifty-six patients with HLHS with available two-dimensional and three-dimensional echocardiograms, and mild or greater TR, were included. TR location, grade, vena contracta area, and TV annular diameter were measured on 2DE and 3DE. Reproducibility was assessed by blinded reviewers. RESULTS: Three-dimensional echocardiography identified the primary jet location as central (57%) followed by anteroseptal (36%). There was poor agreement between findings on 3DE and 2DE for jet location (κ = 0.05; 95 CI, -0.08 to 0.19). Interobserver reproducibility for location on 3DE was excellent (κ = 0.8), whereas reproducibility for 2DE was poor (κ = 0.32). The most common jet location pre-Norwood and pre-Glenn was central (70%), whereas pre-Fontan and post-Fontan, jet location was central (45%) and anteroseptal (48%). Vena contracta area on 2DE correlated moderately with vena contracta area on 3DE (r = 0.60, P < .0001). TV annular diameters on 2DE and 3DE for lateral (r = 0.85, P < .0001) and anteroposterior (r = 0.74, P = .001) dimensions were strongly correlated. CONCLUSIONS: In children with HLHS, assessment of TR location on 2DE had poor agreement with assessment on 3DE and was poorly reproducible. In contrast, TR jet location on 3DE was highly reproducible. Pre-Glenn, a central TR jet was the most common, while post-Glenn, central and anteroseptal locations were equal, highlighting the importance of preoperative identification of TR jet location in patients with HLHS.

Right Ventricular Remodeling in Hypoplastic Left Heart Syndrome is Minimally Impacted by Cardiopulmonary Bypass: A Comparison of Norwood vs. Hybrid.

Right ventricular (RV) remodeling in hypoplastic left heart syndrome (HLHS) begins prenatally and continues through staged palliations. However, it is unclear if the most marked observed remodeling post-Norwood is secondary to cardiopulmonary bypass (CPB) exposure or if it is an adaptation intrinsic to the systemic RV. This study aims to determine the impact of CPB on RV remodeling in HLHS. Echocardiograms of HLHS survivors undergoing stage 1 Norwood (n = 26) or Hybrid (n = 20) were analyzed at pre- and post-stage 1, pre- and post-bidirectional cavo-pulmonary anastomosis (BCPA), and pre-Fontan. RV fractional area change (FAC), vector velocity imaging for longitudinal & derived circumferential deformation (global radial shortening (GRS) = peak radial displacement/end-diastolic diameter), and deformation ratio (longitudinal/ circumferential) were assessed. Both groups had similar age, clinical status and functional parameters pre-stage 1. No difference in RV size and sphericity at any stage between groups. RVFAC was normal (> 35%) throughout for both groups. Both Norwood and Hybrid patients had increased GRS (p = 0.0001) post-stage 1 and corresponding unchanged longitudinal strain, resulting in decreased deformation ratio (greater relative RV circumferential contraction), p = 0.0001. Deformation ratio remained decreased in both groups in subsequent stages. Irrespective of timing of the first CPB exposure, both Norwood and Hybrid patients underwent similar RV remodeling, with relative increase in circumferential to longitudinal contraction soon after stage 1 palliation. The observed RV remodeling in HLHS survivors were minimally impacted by CPB.

A Unique Intracardiac Shunt: Identifying Complex Anatomy in Reoperative Adult Congenital Heart Disease.

Adult patients with repaired congenital heart disease are presenting with previously unseen types of residual lesions and consequences of prior repair. Patients with d-transposition of the great arteries repaired with atrial switch operations are returning with dysrhythmias and atrioventricular valve disease requiring intervention. We present the challenging case of a young adult with a residual shunt identified on preoperative three-dimensional transthoracic echocardiography, the precise anatomy of which was only characterized intraoperatively.

Early tricuspid regurgitation in hypoplastic left heart syndrome is not related to right ventricular function or mechanical dyssynchrony

BACKGROUND: Tricuspid regurgitation (TR) is associated with morbidity and mortality in hypoplastic left heart syndrome (HLHS). We have previously demonstrated that TR prior to stage 2 (S2) surgical palliation is related to tricuspid valve (TV) abnormalities, including dilated annulus and increased leaflet prolapse. Right ventricular (RV) dysfunction and mechanical dyssynchrony have been reported as causes for TR. Thus, we hypothesized that TR and abnormal TV parameters are associated with RV dysfunction. Objective: This study explored the relationship between TV and RV function using quantitative three dimensional echocardiography (3DE) measure of TV parameters and speckle tracking echocardiography (STE) of RV deformation, in HLHS with and without TR. METHODS: Forty-four HLHS patients with median age of 4.7 months (IQR 3.9-5.3) were prospectively recruited prior to S2 palliation. TV parameters assessed using 3DE, included vena contracta area (VCA), leaflet area, prolapse volume, tethering volume, annular bending angle and papillary muscle angle. RV systolic function was assessed by fractional area change and STE derived longitudinal and circumferential strain, strain rate and mechanical dyssynchrony index (MDI). The group was divided into those with (group A) and those without (group B) significant TR by qualitative assessment. RV functional parameters were compared between the two groups using Mann-Whitney signed rank test and Spearman correlation of TV leaflet and annulus area, prolapse and tethering volume, bending angle and VCA, to longitudinal and circumferential strain, strain rate and MDI were performed. RESULTS: Fourteen patients (32%) had moderate or greater TR (group A). RV function parameters were not different between group A and group B. There was no correlation between all 3DE TV parameters and STE RV deformation parameters. CONCLUSION: Contrary to our hypothesis, HLHS RV systolic dysfunction and mechanical dyssynchrony do not play a significant role in early TR. This finding suggests the mechanisms of early TR in HLHS are likely to be secondary to valve and leaflet differences. (AU)

Tricuspid Valve Adaptation during the First Interstage Period in Hypoplastic Left Heart Syndrome.

BACKGROUND: Tricuspid regurgitation (TR) is an important risk factor for morbidity and mortality in hypoplastic left heart syndrome (HLHS), yet the evolution of tricuspid valve (TV) dysfunction in HLHS is poorly understood. This study sought to examine changes in TV function in HLHS between the first two stages of surgical palliation and to determine the mechanism of TR at the time of stage two surgery-bidirectional cavopulmonary anastomosis (BCPA). METHODS: We prospectively investigated 44 infants at two time points-prior to Norwood-Sano (T1 - median age 5.4 days) and prior to BCPA (T2 - median age 4.7 months) using two-dimensional (2DE) and three-dimensional echocardiography (3DE). Right ventricular (RV) size, function and shape was assessed with 2DE. Extracted spatial coordinates from 3DE were used to calculate TV leaflet and annular area, tethering and prolapse volumes, bending angle, and coaptation index. TR was graded qualitatively, and 2D and 3D vena contracta (VC) were measured. RESULTS: The cohort from T1 to T2 had increased indexed leaflet and annular area (P < .0001) and tethering volume (P < .0001), with no change in coaptation. Significant TR was present in 14 infants (32%) at T2 and was associated with greater leaflet (P = .02) and annular areas (P = .002) and greater prolapse volume (P = .008), but not tethering volume or reduced coaptation. At latest follow-up (median 23 months), 13 patients died or required transplantation. Only 3DE VC at T2 was associated with death or transplantation. CONCLUSIONS: The TV in HLHS adapts to interstage stressors (increased preload and afterload) by increasing leaflet size to maintain adequate leaflet coaptation. Significant TR at T2 was associated with greater leaflet size and prolapse. This may represent TV maladaptation from an excessive response in leaflet expansion to stressors.

Tricuspid Valve Repair in Infancy Using Neochordae: Three-Dimensional Echocardiographic Imaging.

Tricuspid regurgitation (TR) in infancy poses a surgical challenge. Both two- and three-dimensional echocardiography (3DE) can provide detailed information about the mechanism(s) of valve failure and insights into valve adaptation during follow-up. We report two patients who underwent tricuspid valve repair using Gore-Tex neochordae, repairs which were facilitated by and assessed with 3DE. Both infants had less than mild residual TR and no valve tethering at hospital discharge. Furthermore, follow-up 3DEs have helped to confirm valve competence, lack of tethering, and growth of the valve and valve apparatus.

Impaired Single Right Ventricular Function Compared to Single Left Ventricles during the Early Stages of Palliation: A Longitudinal Study.

BACKGROUND: Single right ventricles (SRV) are postulated to be disadvantaged compared with single left ventricles (SLV). We compared the evolution of SRV versus SLV function during infancy using conventional measures and speckle-tracking echocardiography (STE). We hypothesized that the SRV is mechanically disadvantaged during early infancy. METHODS: SRVs (n = 32) were compared with SLVs (n = 16) at the neonatal (presurgery) and pre-bidirectional cavopulmonary anastomosis (pre-BCPA) stages. Functional measures (fractional area change, indexed ventricular annular plane systolic excursion [iVAPSE], isovolumic acceleration [IVA], myocardial performance index, E and A velocities, tissue Doppler imaging annular velocities and STE-measured global longitudinal and circumferential strain, strain rate [SR], and early diastolic SR [EDSR]) were compared between SRV and SLV at each stage and between presurgery and pre-BCPA. RESULTS: Compared with SLV, presurgery SRV had lower circumferential strain (-10.6% vs -16.5%; P = .0002) and EDSR (1.41%/sec vs 2.13%/sec; P = .001). Pre-BCPA SRV had decreased IVA (1.2 vs 2.1 m/sec2; P = .006): longitudinal strain (-15.3% vs -19.1%; P = .001), SR (-0.97%/sec vs -1.53%/sec; P = .0001), EDSR (1.5%/sec vs 2.1%/sec; P = .001); circumferential strain (-10.6% vs -14.9%; P = .002), SR (-0.8%/sec vs -1.21%/sec; P = .0001), and EDSR (1.3%/sec vs 1.8%/sec; P = .009). SRV showed reduction of iVAPSE, IVA, s', e', a' velocities, longitudinal strain, SR, EDSR, and circumferential SR (P < .05) from presurgery to pre-BCPA, while circumferential strain was unchanged. SLV showed no significant change in these parameters during this interval. CONCLUSIONS: The progressive reduction in SRV longitudinal and circumferential function suggests that SRV may have a mechanical disadvantage from birth and progressive impairment with age.

Impaired Left Ventricular Reserve in Childhood Cancer Survivors Treated With Anthracycline Therapy.

BACKGROUND: Childhood cancer survivors show evidence of diffuse myocardial fibrosis that is related to exercise capacity. The mechanism of reduced exercise tolerance in anthracycline cardiotoxicity remains unclear. We explored the determinants of exercise intolerance by evaluating left ventricular (LV) distensibility and functional reserve. METHODS: Patients (n = 22) and healthy controls (n = 10) underwent two-dimensional echocardiography while supine, upright, and during cycle exercise. LV distensibility was measured as the change in end-diastolic cavity area (EDCA) from supine to the upright position. LV functional reserve was assessed during peak exercise, and measured as the exercise-induced change in systolic circumferential strain rate (SR) and early-diastolic SR (EDSR). The peak rate of oxygen consumption was measured by indirect calorimetry. RESULTS: Median age of patients was 16 years (range 8-19) and controls 14 years (range 8-19). Median time since anthracycline therapy was 6 years (range 2-16). Peak oxygen consumption was significantly lower in patients compared to controls (35 ml/kg/min [28-60] vs. 45 ml/kg/min [44-53], P = 0.005). Transitioning from the supine position to the upright position caused a similar reduction in LV EDCA, suggesting similar LV distensibility between patients (-22% [-46 to -4]) and controls (-20% [-46 to -3], P = 0.3). However, during exercise, both systolic SR and EDSR reserve were significantly impaired in patients (∆SR: 93% [14-308], ∆EDSR: -4.5% [-88 to 121]) compared to controls (∆SR: 128% [54-230], P = 0.046; ∆EDSR: 74% [22-234], P = 0.02). CONCLUSIONS: Our findings suggest that impaired LV contractility and functional reserve play a role in the reduced exercise capacity in anthracycline cardiotoxicity rather than LV distensibility.

Three-dimensional echocardiography for the assessment of atrioventricular valves in congenital heart disease: past, present and future.

Echocardiography has developed as an imaging technology over 60 years to become the mainstay for investigating heart disease, providing invaluable structural and functional information. In the last 20 years, 3-dimensional echocardiography (3DE) has emerged as an adjunct to 2-dimensional echocardiography in adult and congenital heart disease. Early work with 3-dimensional imaging of the mitral valve describing normal annular shape and function significantly changed the understanding of mitral valve dynamics. Further work led to our current understanding of the mitral valve working as a unit, with all components vital to its normal function. With improving technology and ease of use, similar 3DE techniques have been used in congenital heart disease to study the unique anatomy and function of atrioventricular (AV) valves, specifically the tricuspid valve in hypoplastic left heart syndrome, and the left AV valve in atrioventricular septal defects. This paper describes the role of 3DE in assessing AV valve function in normal valves, and in congenital heart disease.

Childhood presentation of interrupted aortic arch with persistent carotid ducts.

Interrupted aortic arch is a rare condition with typical presentation within the first few weeks of life, as the circulation is dependent upon patency of the arterial duct. Most cases are associated with intracardiac anomalies, the most common being a ventricular septal defect with some degree of hypoplasia and/or obstruction of the left ventricular outflow tract. Presentation beyond infancy is uncommon, and suggests the presence of well-developed collateral circulation. This case of childhood presentation of interrupted aortic arch and intact ventricular septum highlights the very unusual finding of bilateral collateral arteries consistent with persistent carotid ducts. Cardiac MRI angiography with three-dimensional reconstruction defined not only the site of interruption in the aortic arch but also the entire collateral circulation.

Increased common atrioventricular valve tenting is a risk factor for progression to severe regurgitation in patients with a single ventricle with unbalanced atrioventricular septal defect.

OBJECTIVE: Significant atrioventricular valve regurgitation (AVVR) increases mortality in patients with unbalanced atrioventricular septal defects (uAVSDs) and a single ventricle. We tested the hypothesis that abnormal leaflet tethering is associated with progressive AVVR in patients with a single ventricle with uAVSD. METHODS: We retrospectively reviewed the initial presentation and prebidirectional cavopulmonary anastamosis echocardiograms of 46 consecutive patients with uAVSD with single ventricle palliation. AVVR was graded as moderate to severe if the sum of vena contracta width to dominant valve annulus ratio was ≥ 0.33. We measured tenting height, annular to leaflet angle and annular diameter, indexed to patient size where appropriate. Multivariate analysis of variables to predict progressive AVVR was performed. RESULTS: At follow-up of 3.3 ± 2.4 years, 24 patients had mild AVVR (Group A) and 22 had moderate to severe AVVR. Overall mortality was 6%, whereas 10 had valve repair/replacement surgery. Of 22 patients with severe AVVR at follow-up, 9 had severe AVVR at initial presentation (Group B), whereas 13 had mild AVVR at presentation but developed severe AVVR at their prebidirectional cavopulmonary anastamosis echocardiogram (Group C). Group A patients had a smaller tenting height at initial presentation compared with patients in Group B and Group C, and also had early progressive reduction of indexed tenting height (P < .01). An absolute tenting height >6 mm (odds ratio, 6.6; 95% confidence interval, 1.1-39.0; P = .03) at the initial echocardiogram was identified as an independent predictor of subsequent severe AVVR. CONCLUSIONS: Early leaflet tethering is predictive of subsequent AVVR in patients with a single ventricle with uAVSD. Patients with competent AVV had progressive reduction in the degree of leaflet tethering, whereas patients with AVVR did not. This may represent an important adaptive process to maintain valve competency in uAVSD.

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.

Comparison of two surgical techniques for complete atrioventricular septal defect repair using two- and three-dimensional echocardiography.

Different surgical techniques for complete atrioventricular septal defect (CAVSD) repair have been described, with the double-patch technique being most frequently employed. More recently a newer technique using a modified single-patch repair has been advocated. We hypothesized that the modified single-patch technique would result in an increased incidence of the two major post-repair comorbidities, namely, distortion of the left AV valve (LAVV) leaflets and narrowing of the left-ventricular outflow tract (LVOT). We studied 14 patients with CAVSD who underwent either traditional double-patch technique [group 1 (n = 7)] or modified single-patch technique [group 2 (n = 7)]. Preoperative and immediate postoperative two-dimensional (2D) echocardiograms, as well as follow-up 2D and three-dimensional (3D) studies, were reviewed. For group 1, the median age at repair was 4.1 months with a median duration from surgical repair and last echocardiogram of 44 months. For group 2, the median age at repair was 3 months with a median duration from surgical repair and last echocardiogram of 28 months. The two groups had similar demographics and ventricular septal defect size before surgery. For the LAVV, no significant difference was observed with respect to LAVV annulus size, tenting height, and the size of the vena contracta. Furthermore, there was no significant difference in the 2D echocardiographic areas and volumes of the LVOT between pre-repair and immediate post-repair studies for both groups. At the last evaluation, although there had been growth of the LVOT in both groups, no significant difference between areas and volumes were observed. Areas of the LVOT measured by 3D echocardiography on the final study showed no significant statistical difference between both groups. There was good correlation of the areas measured by 2D and 3D echocardiography within each group. In this small group, modified single-patch technique does not appear to tether the LAVV or promote an increase in regurgitation. In the short term, LVOT growth is unaffected, and the repair does not promote LVOT obstruction. 3D echocardiography is useful for area measurements of the LVOT and showed good correlation with areas measured by assumption of the LVOT shape as determined using 2D techniques.

Three-dimensional echocardiography in the assessment of congenital mitral valve disease.

Congenital mitral valve abnormalities are rare and cause mitral stenosis, regurgitation, or a combination of the two. Three-dimensional echocardiography has provided new insight into the structure and function of both normal and abnormal mitral valves. Three-dimensional imaging permits accurate anatomic diagnosis and enhances two-dimensional echocardiographic data. Moreover, it enables echocardiographers to communicate effectively with cardiothoracic surgeons when displaying, analyzing, and describing pathology. The purpose of this report is to review congenital mitral valve disease, focusing on the benefits of three-dimensional echocardiography in its evaluation.

Effectiveness of prenatal screening for congenital heart disease: assessment in a jurisdiction with universal access to health care.

BACKGROUND: Neonates with certain forms of severe congenital heart disease (CHD) diagnosed prenatally might have better outcomes in comparison with those diagnosed after birth. The proportion of prenatally detected neonates with severe CHD and the effect of prenatal diagnosis on clinical outcomes have not been previously investigated in Canada. METHODS: We retrospectively studied infants in Alberta, Canada, who required surgical or catheter intervention for CHD at younger than 1 year of age, between January 2007 and December 2010, and pregnancy terminations affected by CHD. RESULTS: Of the 374 subjects identified (327 infants, 47 pregnancies with termination), 188 (50%) were detected prenatally. Failure of prenatal diagnosis was associated with anomalies not involving the 4-chamber view on ultrasound (odds ratio, 1.86; 95% confidence interval, 1.48-2.35; P < 0.001) and region of residence (P = 0.04). Prenatal detection was associated with fewer days to hospital admission (P < 0.001), fewer days to surgery (P = 0.003), and greater use of prostaglandins (P = 0.001). Infants diagnosed prenatally who underwent surgery within 15 days of age had higher preductal O2 saturations (P = 0.04), fewer days to admission (P = 0.03), and less frequently required preoperative intubation (P = 0.004), and inotropes (P = 0.001). Pregnancy termination occurred among 49% of fetuses detected before 24 weeks' gestation. CONCLUSIONS: Only 50% of fetuses and/or neonates with severe CHD managed in Alberta have a prenatal diagnosis. The likelihood of prenatal detection is influenced by the status of the 4-chamber view on ultrasound and the region of maternal residence indicating heterogeneous access to fetal echocardiography within Alberta. Prenatal detection might improve clinical outcomes for neonates with severe CHD.

The assessment of atrial function in single ventricle hearts from birth to Fontan: a speckle-tracking study by using strain and strain rate.

BACKGROUND: Single ventricle (SV) exercise performance is impaired and limited by reduced ventricular preload reserve. The atrium modulates ventricular filling, and enhancement of atrial compliance can increase cardiac performance. We aimed to study atrial mechanics in SV hearts across staged surgical palliation compared with healthy children by using novel speckle-tracking echocardiography techniques. METHODS: A cross-sectional study of 81 patients with SV (1 day to 6.5 years) at 4 stages of surgical palliation (presurgery, 22; prebidirectional cavopulmonary anastomosis, 23; pre-Fontan, 22; post-Fontan, 14). The dominant atrium was assessed with speckle-tracking echocardiography for active (εact), conduit (εcon), and reservoir (εres) strain; strain rate (SR); and εact/εres ratio before each stage of surgical palliation. Findings were compared with the left atrium of 51 healthy children (1 day to 5.5 years). RESULTS: Single ventricle atrial size was increased (P < .01), and atrial εres was decreased (P < .01) compared with healthy controls. SV atrial εcon (P < .01) and SRcon (P < .0001) was decreased, increased εact persisted (P < .05), and εact/εres was increased (P < .001) between surgical stages. Although the expected maturational trend of increasing εcon, decreasing εact, and εact/εres occurred in SV, they lagged behind healthy maturational changes (P < .0001). CONCLUSION: Single ventricle atrium is dilated, has deceased compliance, decreased early diastolic emptying, and increased reliance on active atrial contraction for ventricular filling. This deviates from normal early childhood maturational changes and appears to parallel those of an atrium facing early ventricular diastolic dysfunction.

Partial zone of apposition closure in atrioventricular septal defect: are papillary muscles the clue.

BACKGROUND: Long-term survival after atrioventricular septal defect repair is excellent; however, postoperative left atrioventricular valve regurgitation affects morbidity and quality of life. Left atrioventricular valve regurgitation is the most common reason for reoperation after repair and it is critical that clinicians recognize pathologic mechanisms pre-repair. METHODS: In this single-center experience, we identified a pattern of left atrioventricular valve abnormality in 5 cases presenting for routine surgical repair between 1 month and 24 years of age. We reviewed two-dimensional and real-time three-dimensional echocardiographic and surgical findings to assess for specific valvar or sub-valve abnormalities, including short chordae, commissural deformities, and an eccentric zone of apposition. Two-dimensional echocardiography was used to assess the degree of preoperative and postoperative left atrioventricular valve regurgitation. RESULTS: Abnormal features identified included short, thickened chordae, poorly formed superior-mural commissure, and an eccentric zone of apposition. At surgical repair, 2 patients had limited closure of the zone of apposition, as part of a complete repair, and developed only mild left atrioventricular valve regurgitation in short-term follow-up. Two further patients had attempted complete closure of the zone of apposition with moderate postoperative regurgitation ultimately necessitating left atrioventricular valve replacement. CONCLUSIONS: This uncommon form of atrioventricular septal defect is identifiable with echocardiography and may be associated with significant postoperative regurgitation if the zone of apposition is completely sutured at time of repair. Limited closure of the zone of apposition may improve postoperative regurgitation.

Aortico-left ventricular tunnel: the elusive diagnosis.

We present a case of an infant prenatally diagnosed with bilateral outflow-tract obstruction and severe aortic regurgitation who underwent cardiac transplantation at 45 days of life. Aortico-left ventricular tunnel was subsequently diagnosed on pathologic examination of the explant heart. Aortico-left ventricular tunnel is a rare congenital cardiac malformation and can remain undiagnosed if the clinician has a low level of suspicion. Aortico-left ventricular tunnel should be considered in any fetus or newborn with aortic regurgitation.