Publications by authors named "Jeffrey Smallhorn"

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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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).

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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.

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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.

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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.

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Background: Mechanisms of mitral valve regurgitation after atrioventricular septal defect repair are unclear.

Methods: To gain further insight into mitral valve regurgitation, real-time three-dimensional echocardiography was performed in 53 patients after atrioventricular septal defect repair (30 partial and 23 complete) and 40 controls. Mitral valve {x, y, z} coordinates from the annulus, leaflet surface, papillary muscle, and chordal attachments were recorded.

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Background: Differences in single right ventricle (SRV) and single left ventricles (SLV) function are poorly described, although myocardial dysfunction is an important risk factor for morbidity and mortality. The aims of this study were to compare function between patients with SRVs and those with SLVs using newer echocardiographic techniques and to determine differences across staged palliation.

Methods: In this cross-sectional study comparing 30 patients with SRVs and 30 with SLVs of similar ages (2.

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Atrioventricular septal defects comprise a disease spectrum characterized by deficient atrioventricular septation, with several common features seen in all affected hearts and variability in atrioventricular valve morphology and interatrial and interventricular communications. Atrioventricular septal defects are among the more common defects encountered by pediatric cardiologists and echocardiographers. Despite advances in understanding, standard two-dimensional echocardiography may not be the optimal method for the morphologic and functional evaluation of this lesion, particularly malformations of the atrioventricular valve(s).

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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.

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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).

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Objectives: This study aimed to determine the normal variation of left ventricular (LV) isovolumic acceleration (IVA) in healthy children and to assess the feasibility of an entirely noninvasive method for demonstration of the LV force-frequency relationship (FFR).

Background: Pediatric cardiologists continue to seek noninvasive, load-independent indexes for the assessment of LV contractility and myocardial reserve.

Methods: Resting LV IVA was measured by echocardiogram in 236 healthy children and compared with their clinical characteristics.

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