Timothy Colen

Insights into the Evolution of Myocardial Dysfunction in the Functionally Single Right Ventricle between Staged Palliations Using Speckle-Tracking Echocardiography

BACKGROUND The long-term prognosis of hypoplastic left heart syndrome is limited by progressive right ventricular dysfunction. The aim of this study was to determine the trends in single right ventricular systolic function between staged palliative surgeries using speckle-tracking and conventional echocardiography. METHODS There were 76 patients with functionally single right ventricles at the (1) pre-Norwood (n = 26), (2) pre-bidirectional cavopulmonary anastomosis (BCPA; n = 19), (3) pre-Fontan (n = 16), and (4) post-Fontan (n = 15) stages, compared with 30 controls of similar ages. Speckle-tracking-derived longitudinal and circumferential strain and strain rate, postsystolic strain index, and mechanical dyssynchrony index were compared with conventional measures of ventricular function. Differences between stages were analyzed using analysis of variance (P < .05). RESULTS Strain rate was highest at the pre-Norwood stage and decreased at the other stages (longitudinal P < .0001, circumferential P = .0002), as opposed to controls, in whom strain rate was maintained. Longitudinal strain was significantly decreased at the pre-BCPA stage compared with the pre-Norwood stage (P = .004), but circumferential strain was maintained, resulting in a corresponding decrease in the ratio of longitudinal to circumferential strain, which failed to resemble that of controls. Longitudinal (P = .003) and circumferential (P = .002) postsystolic strain indices were greatest at the pre-BCPA stage. CONCLUSIONS A decline in contractility occurred at the pre-BCPA stage. Although there was evidence of adaptation of the single right ventricle, this failed to resemble the normal left ventricle and may be insufficient to handle the chronic volume load or insult from previous surgery. These findings suggest an intrinsic inability of the single right ventricular myocardium to fully adapt to chronic systemic pressures.

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.

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.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.

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.

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.

Isolated Innominate Artery as a Cause of Subclavian Steal and Cerebral Hemisphere Atrophy

A rare case of isolated innominate artery arising from a left persistent arterial duct with a right aortic arch is presented. Of interest in this case is the retrograde flow in the left carotid system, the history of developmental delay, and the magnetic resonance image (MRI) brain findings suggestive of asymmetric volume loss affecting the left cerebral hemisphere. The authors postulate a possible mechanism of subclavian steal.

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.

Tricuspid Regurgitation In Hypoplastic Left Heart Syndrome: Mechanistic Insights On Tricuspid Valve Tethering 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.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.

Population Trends in Prenatal Detection of Transposition of Great Arteries: Impact of Obstetrical Screening Ultrasound Guidelines

Dextro‐transposition of the great arteries (d‐TGA) is one of the most common critical neonatal heart defects, with a low detection rate antenatally. We sought to evaluate trends in the prenatal detection of d‐TGA with or without ventricular septal defect (VSD) in Alberta over the past 13 years, examining the potential impact of ultrasound guidelines incorporating screening of cardiac outflow tracts, updated in 2009–2010 and in 2013, and factors affecting detection of the condition.

Right Atrial Dysfunction in the Fetus with Severely Regurgitant Tricuspid Valve Disease: A Potential Source of Cardiovascular Compromise

Background: In severe right heart obstruction (RHO), redistribution of cardiac output to the left ventricle (LV) is well tolerated by the fetal circulation. Although the same should be true of severely regurgitant tricuspid valve disease (rTVD) with reduced or no output from the right ventricle, affected fetuses more frequently develop hydrops or suffer intrauterine demise. We hypothesized that right atrium (RA) function is altered in rTVD but not in RHO, which could contribute to differences in outcomes. Methods: Multi‐institutional retrospective review of fetal echocardiograms performed over a 10‐year period on fetuses with rTVD (Ebsteins anomaly, tricuspid valve dysplasia) or RHO (pulmonary atresia/intact ventricular septum, tricuspid atresia) and a healthy fetal control group. Offline velocity vector imaging and Doppler measurements of RA size and function and LV function were made. Results: Thirty‐four fetuses with rTVD, 40 with RHO, and 79 controls were compared. The rTVD fetuses had the largest RA size and lowest RA expansion index, fractional area of change, and RA indexed filling and emptying rates compared with fetuses with RHO and controls. The rTVD fetuses had the shortest LV ejection time and increased Tei index with a normal LV ejection fraction. RA dilation (odds ratio, 1.27; 95% CI, 1.05–1.54) and reduced indexed emptying rate (odds ratio, 2.49; 95% CI, 1.07–5.81) were associated with fetal or neonatal demise. Conclusions: Fetal rTVD is characterized by more severe RA dilation and dysfunction compared with fetal RHO and control groups. RA dysfunction may be an important contributor to reduced ventricular filling and output, potentially playing a critical role in the worsened outcomes observed in fetal rTVD. HighlightsThis is the first study to examine intrinsic right atrial function using velocity vector imaging in fetuses with and without right heart disease.Fetuses with regurgitant tricuspid valve disease, including Ebsteins anomaly and tricuspid valve dysplasia, have evidence of impaired right atrial function characterized by increased global size, decreased emptying fraction and reservoir function, and reduced indexed emptying and filling rates.Impaired right atrial function in fetuses with regurgitant tricuspid valve disease may compromise fetal cardiac output, potentially contributing to the higher rate of poor outcomes in this population.