Single Left Ventricle Research Articles

Serial cardiopulmonary exercise testing in young patients after one-and-half ventricle repair and Fontan procedure: a comparative study.

The Fontan procedure is a palliative surgical treatment for different congenital heart diseases with a univentricular heart, but it has been associated with decreased exercise capacity, cardiovascular morbidity, and premature mortality. The one-and-half ventricle repair (1.5VR) was introduced as an alternative to the Fontan procedure, specifically for selected patients with borderline hypoplastic right ventricle (HRV), aiming for a more physiological circulation. Despite these efforts, the benefit of 1.5VR over Fontan circulation comparison on clinical and functional outcomes remains unclear. The aim of this study was to investigate and compare young patients with HRV after 1.5VR with those with functional single right or left ventricles (FSRV or FSLV) after Fontan palliation over a 10-year follow-up period. In this retrospective observational study, serial cardiopulmonary exercise tests (CPETs) performed in patients with 1.5VR and Fontan circulation between September 2002 and March 2024 have been analysed. Only patients with at least 10 years of follow-up were considered. A total of 43 patients were included (age at baseline 8.6±2.6 years): 21 with FSLV, 12 with FSRV, and 10 with 1.5VR. No differences in cardiorespiratory fitness and efficiency were shown at the first CPET assessment among the three groups. At 10-year follow-up, 1.5VR had higher cardiorespiratory fitness and efficiency compared to FSLV and FSRV patients. These findings suggest that the 1.5VR may provide superior long-term functional outcomes than the Fontan procedure in patients with borderline HRV. Further studies are needed to evaluate the impact on hard clinical endpoints.

Relationship Between Obesity and Global Longitudinal Strain in the Pediatric Single Ventricle Fontan Population Across Ventricular Morphologies.

Obesity is associated with diminished myocardial function as measured by strain echocardiography in children and young adults with normal cardiac anatomy. Data are lacking about the effect of obesity on myocardial strain in patients with a single ventricle. In this study, the relationship between body mass index (BMI) and single ventricle myocardial strain in the Fontan population was assessed. Thirty-eight abnormal BMI Fontan cases (21 overweight and 17 obese) and 30 normal BMI Fontan controls matched based on single ventricular morphology, age, and sex were included in the study. Ventricular morphology was categorized as single right ventricle, single left ventricle, or biventricular. Single ventricle global longitudinal peak systolic strain (GLS) and other echocardiographic measurements were performed and compared between groups, with a P≤0.05 defined as significant. The abnormal BMI group demonstrated diminished GLS (-15.7±3.6% versus -17.2±3.2%, [P=0.03]) and elevated systolic blood pressure (P=0.04) compared with the normal BMI group. On subgroup analysis of those with single right ventricle morphology, the abnormal BMI group demonstrated diminished GLS compared with controls. There was no significant difference in GLS between the abnormal BMI and control groups in the single left ventricle and biventricular subgroups. Analyzed by ventricular morphology, no other variables were statistically different in the abnormal BMI group including systolic blood pressure. Inter-reader reproducibility for GLS and strain rate were excellent for both measures. Obesity has an adverse relationship with myocardial strain in the young Fontan population, with the most maladaptive response seen in the single right ventricle.

A Tale of Intricate Connections: An Interesting Case of Congenital Heart Disease with Supraventricular Tachycardia

Double inlet left ventricle (DILV) is a rare complex congenital heart defect characterized by the presence of two atrioventricular valve orifices leading into a single left ventricle. Patients rarely survive beyond teenage years without surgical correction. Supraventricular tachycardia (SVT) in DILV is a rare occurrence that adds an additional layer of complexity to diagnosis and management. Here, we report an exceptional case of DILV who survived well into her fourth decade of life without any surgical correction. The patient presented to us with SVT which lead to the discovery of her unique cardiac anomaly.

Optogenetic Modulation of Arrhythmia Triggers: Proof-of-Concept from Computational Modeling.

Early afterdepolarizations (EADs) are secondary voltage depolarizations associated with reduced repolarization reserve (RRR) that can trigger lethal arrhythmias. Relating EADs to triggered activity is difficult to study, so the ability to suppress or provoke EADs would be experimentally useful. Here, we use computational simulations to assess the feasibility of subthreshold optogenetic stimulation modulating the propensity for EADs (cell-scale) and EAD-associated ectopic beats (organ-scale). We modified a ventricular ionic model by reducing rapid delayed rectifier potassium (0.25-0.1 × baseline) and increasing L-type calcium (1.0-3.5 × baseline) currents to create RRR conditions with varying severity. We ran simulations in models of single cardiomyocytes and left ventricles from post-myocardial infarction patient MRI scans. Optogenetic stimulation was simulated using either ChR2 (depolarizing) or GtACR1 (repolarizing) opsins. In cell-scale simulations without illumination, EADs were seen for 164 of 416 RRR conditions. Subthreshold stimulation of GtACR1 reduced EAD incidence by up to 84.8% (25/416 RRR conditions; 0.1μW/mm2); in contrast, subthreshold ChR2 excitation increased EAD incidence by up to 136.6% (388/416 RRR conditions; 50μW/mm2). At the organ scale, we assumed simultaneous, uniform illumination of the epicardial and endocardial surfaces. GtACR1-mediated suppression (10-50μW/mm2) and ChR2-mediated unmasking (50-100μW/mm2) of EAD-associated ectopic beats were feasible in three distinct ventricular models. Our findings suggest that optogenetics could be used to silence or provoke both EADs and EAD-associated ectopic beats. Validation in animal models could lead to exciting new experimental regimes and potentially to novel anti-arrhythmia treatments. The online version contains supplementary material available at 10.1007/s12195-023-00781-z.

Myocardial strain-curve deformation patterns after Fontan operation.

Myocardial deformation analysis by cardiac MRI (CMR) yielding global circumferential and longitudinal strain (GCS and GLS) is an increasingly utilized method to accurately quantify systolic function and predict clinical events in patients with Fontan circulation. The purpose of this study was to use principal component analysis (PCA) to investigate myocardial temporal deformation patterns derived from strain-time curves to learn about latent strain features beyond peak values. We conducted the study with specific attention to dominant single left or right ventricle (SLV and SRV) morphologies. Methods and Results: Patients remote from Fontan operation who underwent follow-up CMR were analyzed for standard volumetric and function hemodynamics including myocardial deformation parameters including GCS and GLS. We applied PCA to investigate in an unbiased fashion the strain-time curve morphology and to calculate patient specific shape scores. All variables were subjected to single variable Cox regression analysis to detect composite clinical outcome including death, heart transplant, protein losing enteropathy and plastic bronchitis. A total of 122 patients, (SLV = 67, SRV = 55) with a mean age of 12.7years underwent comprehensive CMR analysis. The PCA revealed 3 primary modes of strain-curve variation regardless of single ventricle morphology and type of strain investigated. Principle components (PCs) described changes in (1) strain-time curve amplitude, (2) time-to-peak strain, and (3) post-systolic slope of the strain-time curve. Considering only SLV patients, GCS was only CMR variable predictive of clinical events (HR 1.46, p = 0.020). In the SRV group, significant CMR predictors of clinical events were derived indexed end-diastolic (HR 1.02, p = 0.023) and end-systolic (HR 1.03, p = 0.022) volumes, GCS (HR 1.91, p = 0.003) and its related first component score (HR 1.20, p = 0.005), GLS (HR 1.32, p = 0.029) and its third component score (HR 1.58, p = 0.017). CMR derived global strain measures are sensitive markers of clinical outcomes in patients with Fontan circulation, particularly in patients with the SRV morphology. Myocardial strain-time curve morphology specific to SLV and SRV patients inspired by unbiased PCA technique can further aid with predicting clinical outcomes.

Respiratory Muscle Function and Exercise Performance in Adult Patients with Fontan Circulation.

At rest, a good Fontan circulation can provide a normal cardiac output (CO). However, as a consequence of its unique hemodynamic nature, the limitations of the Fontan circuit are exposed during exercise. We aimed to provide a comprehensive assessment of the pathophysiology of exercise in adult Fontan patients (FPs) and identify factors limiting their functional capacity (FC). In a single-center study conducted in 37 FPs aged ≥16 years and 19 healthy-controls (HCs) who underwent CPET on a cycle ergometer in February and March 2022, the mean peakVO2 was 21 ± 5.4 mL/kg/min, which was 55% of the predicted value. Morphologically, the left single ventricle showed a higher peakVO2% predicted value (57.4 ± 14.4% vs. 43.4 ± 8.1%, p = 0.045). The factors associated with low peakVO2 values were an early flattened or descending O2 pulse at maximal exertion (52 ± 14% vs. 62 ± 12.5, p = 0.04 and 47.6 ± 9% vs. 60 ± 14, p = 0.018, respectively) and chronotropic insufficiency (53 ± 12% vs. 69.8 ± 20%, p = 0.008). The OUES was found to be a useful parameter to assess the FC in FPs in maximal and submaximal exercise testing. A strong positive correlation was observed between the %OUES and peakVO2%predicted (r = 0.726, p > 0.001). The lung function was impaired in the FPs, mostly with a mild restrictive pattern (56.8%). The FPs showed lower inspiratory muscle strength compared to the HCs but it was not statistically associated with either the peakVO2 or VE/VCO2 slope. Regular intense physical activity improves one's FC. Although FPs have inspiratory muscle weakness, its impact on their FC is unclear. The peakVO2% predicted grew progressively higher as the level of physical activity increased (low level 49.5 ± 14%, moderate level 55 ± 12%, intense level 69 ± 20%).

Longitudinal Changes in Ventricular Mechanics in Adolescents After the Fontan Operation

Ventricular dysfunction is a significant clinical challenge in the long-term follow-up of patients with single-ventricle (SV) physiology. Ventricular function and myocardial mechanics can be studied using speckle-tracking echocardiography, which provides information on myocardial deformation. Limited information is available on serial changes in SV myocardial mechanics after the Fontan operation. The aim of this study was to describe serial changes in myocardial mechanics in children after the Fontan operation and the relationship of these changes with myocardial fibrosis markers as obtained by cardiac magnetic resonance and exercise performance parameters. The authors hypothesized that ventricular mechanics decline in patients with SVs over time and are associated with increased myocardial fibrosis and reduced exercise performance. A single-center retrospective cohort study including adolescents after the Fontan operation was conducted. Ventricular strain and torsion were assessed using speckle-tracking echocardiography. Cardiac magnetic resonance and cardiopulmonary exercise testing data closest to the latest echocardiographic examinations were performed. The most recent follow-up echocardiographic and cardiac magnetic resonance data were compared with those from sex- and age-matched control subjects and with individual patients' early post-Fontan data. Fifty patients with SVs (31 left ventricle, 13 right ventricle [RV], and six codominant) were included. Median time at follow-up echocardiography from the time of Fontan was 12.8years (interquartile range [IQR], 10.6 to 16.6years). Compared with early post-Fontan echocardiography, follow-up assessment showed reduced global longitudinal strain (-17.5% [IQR, -14.5% to -19.5%] vs -19.8% [IQR, -16.0% to -21.7%], P=.01], circumferential strain (-15.7% [IQR, -11.4% to -18.7%] vs -18.9% [IQR, -15.2% to -25.0%], P=.009), and torsion (1.28°/cm [IQR, 0.51°/cm to 1.74°/cm] vs 1.72°/cm [IQR, 0.92°/cm to 2.34°/cm], P=.02), with decreased apical rotation but no significant change in basal rotation. Single RVs had lower torsion compared with single left ventricles (1.04°/cm [IQR, 0.12°/cm to 2.20°/cm] vs 1.25°/cm [IQR, 0.25°/cm to 2.51°/cm], P=.01). T1 values were higher in patients with SV compared with control subjects (1,009±36 vs 958±40msec, P=.004) and in those with single RVs compared with single left ventricles (1,023±19 vs 1,006±17msec, P=.02). T1 was correlated with circumferential strain (r=0.59, P=.04) and inversely correlated with O2 saturation (r=-0.67, P<.001) and torsion (r=-0.71, P=.02). Peak oxygen consumption was correlated with torsion (r=0.52, P=.001) and untwist rates (r=0.23, P=.03). After the Fontan procedures, there is a progressive decrease in myocardial deformation parameters. The progressive decrease in SV torsion is related to a decrease in apical rotation, which is more pronounced in single RVs. Decreased torsion is associated with increased markers of myocardial fibrosis and lower maximal exercise capacity. Torsional mechanics may be an important parameter to monitor after Fontan palliation, but further prognostic information is required.

Comparison of cardiac function between single left ventricle and tricuspid atresia: assessment using echocardiography combined with computational fluid dynamics.

Patients with single left ventricle (SLV) and tricuspid atresia (TA) have impaired systolic and diastolic function. However, there are few comparative studies among patients with SLV, TA and children without heart disease. The current study includes 15 children in each group. The parameters measured by two-dimensional echocardiography, three-dimensional speckle tracking echocardiography (3DSTE), and vortexes calculated by computational fluid dynamics were compared among these three groups. Twist is best correlated with ejection fraction measured by 3DSTE. Twist, torsion, apical rotation, average radial strain, peak velocity of systolic wave in left lateral wall by tissue Doppler imaging (sL), and myocardial performance index are better in the TA group than those in the SLV group. sL by tissue Doppler imaging in the TA group are even higher than those in the Control group. In patients with SLV, blood flow spreads out in a fan-shaped manner and forms two small vortices. In the TA group, the main vortex is similar to the one in a normal LV chamber, but smaller. The vortex rings during diastolic phase are incomplete in the SLV and TA groups. In summary, patients with SLV or TA have impaired systolic and diastolic function. Patients with SLV had poorer cardiac function than those with TA due to less compensation and more disordered streamline. Twist may be good indicator for LV function.

Contraction Patterns of Post-Fontan Single Right Ventricle Versus Normal Left and Right Ventricles in Children: Insights From Principal Strain Analysis

Principal strain (PS) analysis quantifies three-dimensional myocardial deformation using three-dimensional speckle-tracking echocardiography. It defines both the amplitude and direction of the principal myocardial contraction, expressed as PS, and a perpendicular secondary strain of lower intensity. The aims of this study were to apply PS analysis to describe the contractile pattern in the single right ventricle (SRV) functioning as a systemic chamber in hypoplastic left heart syndrome, compared with the normal left ventricle (LV) and right ventricle (RV), and to compare SRV function using conventional echocardiographic evaluations. Fifty-four post-Fontan patients with hypoplastic left heart syndrome and age-matched control subjects (normal LV, n=64; normal RV, n=48) underwent computation of PS lines, ejection fraction (EF), end-diastolic volume indexed to body surface area, PS, secondary strain, circumferential strain, and longitudinal strain. The PS lines were compared between groups. Linear regressions with coefficient determination (R2) of strains, fractional area change, and tricuspid annular plane systolic excursion with EF and end-diastolic volume index were assessed in SRV. Additionally, the hypoplastic left heart syndrome cohort was equally divided into two groups with higher and lower EFs, followed by comparison of all parameters. The pattern of PS lines demonstrated a left-handed direction in the anterior free wall, a right-handed direction in the posterior free wall, and a circumferential direction in the medial wall in SRV. In contrast, in the normal LV, the principal contraction is in the circumferential direction, whereas in the normal RV, it is predominantly longitudinal. The R2 values for PS, secondary strain, and circumferential strain on EF were high (0.88, 0.72, and 0.90, respectively), whereas the R2 value for longitudinal strain was comparable with that for fractional area change (0.56 and 0.55). All parameters were independent of end-diastolic volume index. PS lines in the higher EF group showed a more circumferential orientation than in the lower EF group in SRV. PS analysis provides a unique functional map of SRV contraction. This map differs from corresponding maps of the normal LV and RV. This may be helpful in understanding the mechanisms of SRV function, although future longitudinal studies are needed.

T1 mapping of the myocardium and liver in the single ventricle population.

Fontan associated liver disease (FALD) is an increasingly recognized complication of the single ventricle circulation characterized by hepatic venous congestion leading to hepatic fibrosis. Within the Fontan myocardium, fibrotic myocardial remodeling may occur and lead to ventricular dysfunction. Magnetic resonance imaging (MRI) T1 mapping can characterize both myocardial and liver properties. The aim of this study was to compare myocardial and liver T1 between single ventricle patients with and without a Fontan and biventricular controls. A retrospective study of 3 groups of patients: 16 single ventricle patients before Fontan (SVpre 2 newborns, 9 pre-Glenn, 5 pre-Fontan, 31% single right ventricle [SRV]), 16 Fontans (56% SRV) and 10 repaired d-transposition of the great arteries (TGA). Native modified Look-Locker inversion T1 times were measured in the myocardium and liver. Cardiac MRI parameters, myocardial and liver T1 values were compared in the three groups. Correlations were assessed between liver T1 and cardiac parameters. Myocardial T1 was higher in SVpre (1,056 ± 48ms) and Fontans (1,047 ± 41ms) compared to TGA (1,012 ± 48ms, P < 0.05). Increased liver T1 was found in both SVpre (683 ± 82ms) and Fontan (727 ± 49ms) patients compared to TGA patients (587 ± 58ms, P < 0.001). There was no difference between single left ventricle (SLV) versus SRV myocardial or liver T1. Liver T1 showed moderate correlations with myocardial T1 (r = 0.48, confidence interval [CI] 0.26-0.72) and ejection fraction (r = -0.36, CI -0.66-0.95) but not with other volumetric parameters. Increased liver T1 at both pre- and post-Fontan stages suggests there are intrinsic liver abnormalities early in the course of single ventricle palliation. Increased myocardial T1 and its relationship to liver T1 suggest a combination of edema from passive venous congestion and/or myocardial fibrosis occurring in this population. Liver T1 may provide an earlier marker of liver disease warranting further study.

Abstract 9841: Outcomes Following Biventricular Repair of Atrioventricular Septal Defect With a Single Left Ventricular Papillary Muscle

Introduction: In patients with atrioventricular septal defect (AVSD) with single papillary muscle attachments in the left ventricle (LV), the left AV valve (LAVV) is at risk for suboptimal repair. This study aimed to evaluate outcomes following repair of AVSD with single LV papillary muscle attachments and to identify preoperative predictors of postoperative LAVV outcomes. Methods: All patients with AVSD and anatomically or functionally single LV papillary muscle who underwent biventricular repair at our institution from 07/01/2000 - 07/01/2020 were retrospectively reviewed. Univariate analysis was used to identify associations between patient demographics, preoperative echocardiographic measures, and surgical characteristics with the degree of LAVV stenosis or regurgitation postoperatively and the need for reintervention on the LAVV. Results: Of 38 patients included, nearly all (97%) were repaired with no or partial closure of the LAVV cleft. Freedom from LAVV reintervention was 91% and 84% at 1 and 3 years. Five patients (13%) required reintervention on the LAVV with a median time to reintervention of 3.3 months post-AVSD repair; indication was LAVV regurgitation for four of the five patients. Preoperative LAVV regurgitation &gt; mild was associated with an increased risk for LAVV reintervention (p= 0.02). At discharge, 63% of patients had &gt; mild LAVV regurgitation and 5% had &gt; mild LAVV stenosis. At most recent follow-up, 32% had &gt; mild LAVV regurgitation and 12% had &gt; mild LAVV stenosis. Patients with younger age at repair and preoperative AV valve index &lt;0.67 had significantly increased risk of &gt; mild LAVV regurgitation at discharge (p=0.01 and p=0.04, respectively), however this did not persist at most recent follow-up. More pronounced unbalance of the AVSD was not associated with postoperative LAVV stenosis. Conclusions: Despite concern for repair in patients with AVSD and single papillary muscle attachments, surgical outcomes are favorable with low risk for reintervention. Risk of LAVV stenosis is low when repair of LAVV cleft is modified. Preoperative LAVV regurgitation, younger age at repair, and more pronounced unbalance of the AVSD predicted early postoperative LAVV regurgitation, with improvement over time.

Cardiopulmonary Exercise Test Outcomes in Fontan Patients With Right Versus Left Single Ventricle Morphology.

Background: Congenital heart defects (CHDs) palliated with Fontan surgery often result in a functional single ventricle that is either a morphologically right or left ventricle, and much less commonly undefined. Given this departure from normal physiology, especially for systemic right ventricle Fontan patients, our study sought to compare cardiopulmonary exercise test (CPET) results of adult patients with single right ventricle (SRV) and single left ventricle (SLV) morphology. Methods: Of 237 Fontan patients from the Ahmanson/UCLA Adult Congenital Heart Disease Center database, 135 patients met the inclusion criteria and were split into 2 groups: SRV (n = 44) and SLV (n = 91). Data were collected on baseline demographics, cardiac history, and CPET results. The 2 groups were compared using unpaired t-test, Mann-Whitney, or Chi-square test. Results: Regarding baseline demographics, SRV patients underwent CPET at a slightly younger age than the SLV group (26.5 ± 6.2 vs 29.6 ± 8.5 years, P = .03). There were no significant differences in CPET parameters (including peak heart rate, oxygen saturation, and maximum VO2/kg) between the SRV and SLV groups. When evaluated subsequent CPET at 3 to 4 years, there was no difference in CPET peak heart rate, peak oxygen saturation, and maximum VO2/kg between the 2 groups. Conclusions: This single-center retrospective analysis suggests that dominant single ventricle morphology may not be associated with an appreciable difference in exercise performance in adult survivors with a Fontan palliation.

Effect of Leisure Sports on Exercise Capacity and Quality of Life in Patients with a Fontan Circulation

Despite improvement in survival, patients with a Fontan circulation are at risk for numerous complications, and exercise capacity and quality of life are usually reduced compared with healthy controls. However, only a few studies have assessed the impact of the amount of sporting activity on exercise capacity and health-related quality of life. We analyzed cardiopulmonary exercise tests (CPET) in a large cohort of patients with a Fontan circulation. Questionnaires were used to assess health-related quality of life and sporting activity. A total of 79 patients with a median age of 13.0 (6.5 to 34.4)years at CPET were included (female, n=31). Questionnaires revealed that 80% of patients (n=63) do leisure sports with 43% (n=27) exercising more than 2hours per /week. In a subgroup analysis on pediatric patients (n=52) we found that nearly all participate in school sports (n=51) and report good subjective health (n=48). In the pediatric subgroup, oxygen uptake at the anaerobic threshold and peak oxygen uptake correlated with subjective health (p<0.05) and the amount of leisure sports activity (p<0.01). In the overall cohort, running time and running distance were significantly associated with the hours of sports per week (p <0.01). CPET results did not significantly differ between single right and single left ventricle patients. Furthermore, an open fenestration was not associated with reduced exercise capacity. In conclusion, most patients with a Fontan circulation participate in leisure sports and report good subjective healthiness. In pediatric patients, increased sports activity is associated with better exercise capacity and subjective healthiness.

610 Fontan associated kidney and liver disease: can we predict organ involvement with echocardiographic assessment of systolic function and atrioventricular valve insufficiency?

Abstract Aims Fontan operation represents the surgical palliative option for congenital heart disease with single ventricle physiology. With the improvement of surgical and percutaneous technique, we are facing a growing population of patients with an unique pathophysiology and potential complications. Methods and results Patients that underwent Fontan palliation in our centre between 1993 and 2016 were included in this prospective study. We excluded patients with major congenital renal anomalies, those that underwent cardiac transplantation, and redo-Fontan patients. All the subjects underwent clinical evaluation, laboratory exams with complete renal and hepatic function, transient hepatic elastography, and complete cardiac evaluation. We used Schwartz equation for estimating glomerular filtration rate in patients younger than 18 years, and CDK-EPI equation for adult patients. We enrolled 35 patients, 46% female (N = 16), and 54% male (N = 19). Medium age was 17 years old, median age 15 years old (range: 10–31 years old). Medium time from Fontan completion was 160 months (range: 57–340 months). Regarding to cardiac anatomy, 10 patients had functional single left ventricle (FSLV, 28.5%) and 21 a functional single right ventricle (FSRV, 60%); 4 patients had undetermined single ventricle (11.5%). Total cavo-pulmonary connection (TCPC) with intracardiac lateral tunnel was performed in 7 patients (20%, N = 7), whereas 28 patients had TCPC with external conduit (80%). Data from echocardiographic evaluation showed a medium EF established with Simpson’s method of 60% in patients with FSLV; patients with a FSRV or undetermined single ventricle had a medium FAC of 41.1%, with 15.1% having a reduced FAC &amp;lt; 35%. No FSLV patients had an EF &amp;lt; 50%. When using creatinine-based formula, data about renal function in our population showed a stage 2 chronic kidney disease (eGFR: 60–89 ml/min 1.73 mq) in 11% of total population (N = 4), that became 26% when using cystatin C-based equation (N = 9), with one patient showing a moderate reduced loss of kidney function (eGFR: 40–59 ml/min 1.73 mq). Urinalysis showed 29% (N = 10) of patients having microalbuminuria (microalbumin/creatinine ratio between 30 and 300 mg/g). Statistical analysis demonstrated a negative correlation between systolic function (TAPSE for FSRV) and cystatin C blood levels (Pearson’s R −0.428, P = 0.053), and between systolic function (FAC and Simpson) and microalbuminuria (Pearson’s R −0.414 with P = 0.049 and Pearson’s R −0.754 with P = 0.019, respectively). Transient elastography reported 10 patients (29.4%) with abnormal hepatic stiffness for Fontan patients. That condition appeared to be more frequent in patients with higher grade of AV valve insufficiency (P &amp;lt; 0.05). Conclusions Our population showed an higher prevalence of FSRV Fontan patients, with an expected lower systolic function compared with FSLV. 2D evaluation of systolic function showed a linear inverse correlation with renal function, suggesting that Fontan patients need a closer renal monitoring. Hepatic stiffness, which is a warning sign of potential hepatic cirrhosis need to be monitored in all Fontan patients, especially those with a worse AV valve insufficiency.

613 Fontan associated nephropathy: does diastolic function play a role?

Abstract Aims In Fontan patients, the pathophysiology of diastolic function and its relationship with systemic complications are still not well understood. Methods and results This is a prospective study including patients who underwent Fontan completion in our centre between 1993 and 2016. We excluded patients with major congenital renal anomalies, those who underwent cardiac transplantation and redo-Fontan patients. All the subjects underwent clinical evaluation, laboratory exams with complete renal and hepatic function, transient hepatic elastography, and complete cardiac evaluation. We used Schwartz equation for estimating glomerular filtration rate in patients younger than 18 years, and CDK-EPI equation for adult patients. We enrolled 35 patients, 46% female (N = 16), and 54% male (N = 19). Medium age was 17 years old (range: 10–31 years old). Medium time from Fontan completion was 160 months (range: 57–340 months). Ten patients had a functional single left ventricle (FSLV, 28.5%) and 21 a functional single right ventricle (FSRV, 60%); four patients had an undetermined single ventricle (11.5%). Data from renal function assessment showed a prevalence of stage 2 chronic kidney disease (eGFR: 60–89 ml/min 1.73 mq). Of those, 11% with creatinine-based equation and 26% (N = 9) when using cystatin C-based equation, with one patients showing a moderate reduced loss of kidney function (eGFR: 40–59 ml/min/1.73 mq). Most of the patients with reduced eGFR measured with cystatin C were FSRV (89%). None had laboratory markers of acute tubular damage, but four patients had signs of chronic tubular dysfunction with elevation of beta 2 microglobulin (13%). Echocardiographic evaluation of diastolic function showed two patients with baseline E/A &amp;lt; 1 (6%, tot N = 33) and 11/33 (33%) pts with abnormal E/E′ (&amp;gt;12). All of them were FSRV patients (100%). Interestingly, statistical correlation between diastolic parameters and renal function showed a significant association between tubular damage parameters, such as alfa1microglobulin and beta2microglobulin, and E/E′ (Pearson’s R 0.4 and 0.48, respectively, P &amp;lt; 0.05), both for FSLV and FSRV patients. Diastolic function appeared to be associated also with glomerular filtration: we found a statistically significant direct correlation between diastolic pulmonary wave deceleration time (dt D wave) and creatinine value (Pearson’s R 0.49, P &amp;lt; 0.05). Supporting the role of diastolic function in Fontan systemic complications is the linear correlation we found with hepatic tests: higher values of aspartate aminotransferase and of gamma-glutamyltransferase were associated with worse diastolic ventricular filling (longer dt D wave and E wave deceleration time, lower TDI early diastolic wave; Pearson’s R 0.45, 0.5, and −0.41, respectively, P &amp;lt; 0.05). Conclusions Fontan-related nephropathy is associated with worsening diastolic function, which was more represented in FSRV patients. Diastolic function is also associated with liver disease in Fontan patients. Those data suggest renal and liver function should be closely monitored in patients with impaired diastolic function.

Two-scale haemodynamic modelling for patients with Fontan circulation

Abstract Palliation of congenital single ventricle heart defects suggests multi-stage surgical interventions that divert blood flow from the inferior and superior vena cava directly to the right and left pulmonary arteries, skipping the right ventricle. Such system with cavopulmonary anastomoses and single left ventricle is called Fontan circulation, and the region of reconnection is called the total cavopulmonary connection (TCPC). Computational blood flow models allow clinicians to predict the results of the Fontan operation, to choose an optimal configuration of TCPC and thus to reduce negative postoperative consequences. We propose a two-scale (1D3D) haemodynamic model of systemic circulation for a patient who has underwent Fontan surgical operation. We use CT and 4D flow MRI data to personalize the model. The model is tuned to patient’s data and is able to represent measured time-averaged flow rates at the inlets and outlets of TCPC, as well as pressure in TCPC for the patient in horizontal position.We demonstrate that changing to quiescent standing position leads to other patterns of blood flow in regional (TCPC) and global haemodynamics. This confirms clinical data on exercise intolerance of Fontan patients.

Role of cardiac magnetic resonance strain analysis in patients with hypoplastic left heart syndrome in evaluating right ventricular (dys)function: a systematic review.

Right ventricular dysfunction predicts death in patients with hypoplastic left heart syndrome (HLHS), but differences in morphology and loading conditions make calculation of the ejection fraction (EF), a challenging measure of its function. Our goal was to evaluate how strain measurements with cardiac magnetic resonance feature tracking could be used to evaluate right ventricular function in patients with HLHS. A systematic search of the literature was performed by 2 independent researchers using the terms 'population', 'intervention', 'comparison', 'outcome' and 'time criteria'. PubMed and the Ovid database were searched according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Our review included 8 studies with 608 participants with ventricular strain values obtained using cardiac magnetic resonance feature tracking. After stage I palliation, global strain was reduced in patients after a hybrid procedure and a right ventricle-to-pulmonary artery conduit compared with a modified Blalock-Taussig shunt despite similar EFs. Global longitudinal strain did not differ between stage II and stage III (Fontan) palliation. Fontan patients had significantly impaired global longitudinal and circumferential strain compared to the left ventricular strain of the controls. Studies of Fontan patients that included patients with HLHS who were part of a cohort with a single right ventricle showed impaired global circumferential strain compared with the cohort with a single left ventricle, with controls, and over time. In this group, impaired global circumferential strain was associated with major adverse cardiac events. Cardiac magnetic resonance feature tracking can be used in patients with HLHS to evaluate RV strain and demonstrate differences between surgical strategies, over time and compared with controls. It could be used alongside clinical symptoms and EF values to detect ventricular dysfunction.

Myocardial Deformation in Fontan Patients Assessed by Cardiac Magnetic Resonance Feature Tracking: Correlation with Function, Clinical Course, and Biomarkers

Cardiac MR (CMR) is a standard modality for assessing ventricular function of single ventricles. CMR feature-tracking (CMR-FT) is a novel application enabling strain measurement on cine MR images and is used in patients with congenital heart diseases. We sought to assess the feasibility of CMR-FT in Fontan patients and analyze the correlation between CMR-FT strain values and conventional CMR volumetric parameters, clinical findings, and biomarkers. Global circumferential (GCS) and longitudinal (GLS) strain were retrospectively measured by CMR-FT on Steady-State Free Precession cine images. Data regarding post-operative course at Fontan operation, and medication, exercise capacity, invasive hemodynamics, and blood biomarkers at a time interval ± 6 months from CMR were collected. Forty-seven patients underwent CMR 11 ± 6 years after the Fontan operation; age at CMR was 15 ± 7 years. End-diastolic volume (EDV) of the SV was 93 ± 37 ml/m2, end-systolic volume (ESV) was 46 ± 23 ml/m2, and ejection fraction (EF) was 51 ± 11%. Twenty (42%) patients had a single right ventricle (SRV). In single left ventricle (SLV), GCS was higher (p < 0.001), but GLS was lower (p = 0.04) than in SRV. GCS correlated positively with EDV (p = 0.005), ESV (p < 0.001), and EF (p ≤ 0.0001). GLS correlated positively with EF (p = 0.002), but not with ventricular volumes. Impaired GCS correlated with decreased ventricular function (p = 0.03) and atrioventricular valve regurgitation (p = 0.04) at echocardiography, direct atriopulmonary connection (p = 0.02), post-operative complications (p = 0.05), and presence of a rudimentary ventricle (p = 0.01). A reduced GCS was associated with increased NT-pro-BNP (p = 0.05). Myocardial deformation can be measured by CMR-FT in Fontan patients. SLVs have higher GCS, but lower GLS than SRVs. GCS correlates with ventricular volumes and EF, whereas GLS correlates with EF only. Myocardial deformation shows a relationship with several clinical parameters and NT-pro-BNP.

Diastolic inflow is associated with inefficient ventricular flow dynamics in Fontan patients

ObjectiveThis study used cardiac magnetic resonance imaging to evaluate flow characteristics and ventricular hemodynamics for children with single right (hypoplastic left heart syndrome) and single left (hypoplastic right heart syndrome) systemic ventricle anatomy after Fontan palliation compared with normal biventricular controls. MethodsTwenty children with single ventricle anatomy (hypoplastic left heart syndrome, n = 10; hypoplastic right heart syndrome, n = 10) underwent standardized 4-dimensional flow cardiac magnetic resonance and were compared with age-matched controls (n = 10). End-diastolic volume was partitioned into 4 defined components of variable kinetic energy (direct flow, retained inflow, delayed ejection, and residual volume) and compared between groups. Further, volumetric and functional parameters as defined by cardiac magnetic resonance were evaluated. ResultsChildren with hypoplastic left heart syndrome had significantly increased indexed end-diastolic and end-systolic volumes compared with both hypoplastic right heart syndrome and control groups. Flow component analysis demonstrated diastolic inefficiency in both hypoplastic left heart syndrome and hypoplastic right heart syndrome groups compared with controls as defined by decreased direct flow and increased residual volumes. Decreased direct flow correlated with decreased ejection fraction and increased end-diastolic and end-systolic volume indices. Increased residual volume correlated with decreased ejection fraction and increased end-systolic volume index. ConclusionsFontan-palliated patients with single ventricle physiology (hypoplastic left heart syndrome and hypoplastic right heart syndrome) demonstrate altered and inefficient flow patterns in the systemic ventricle as defined by 4-dimensional flow cardiac magnetic resonance compared with normal biventricular controls. Decreased direct flow and increased residual volume indicate that diastolic ventricular dysfunction is prevalent after Fontan palliation. This study provides a foundation for future predictive modeling and cardiac magnetic resonance flow diagnostic studies in this high-risk patient population.

Myocardial deformation in patients with a single left ventricle using 2D cardiovascular magnetic resonance feature tracking: a case\u2013control study

Ventricular dysfunction is a well-known complication in single ventricle patients in Fontan circulation. As studies exclusively examining patients with a single left ventricle (SLV) are sparse, we assessed left ventricular (LV) function in SLV patients by using 2D-cardiovascular magnetic resonance (CMR) feature tracking (2D-CMR-FT) and 2D-speckle tracking echocardiography (2D-STE). 54 SLV patients (11.4, 3.1–38.1 years) and 35 age-matched controls (12.3, 6.3–25.8 years) were included. LV global longitudinal, circumferential and radial strain (GLS, GCS, GRS) and strain rate (GLSR, GCSR, GRSR) were measured using 2D-CMR-FT. LV volumes, ejection fraction (LVEF) and mass were determined from short axis images. 2D-STE was applied in patients to measure peak systolic GLS and GLSR. In a subgroup analysis, we compared double inlet left ventricle (DILV) with tricuspid atresia (TA) patients. The population consisted of 19 DILV patients, 24 TA patients and 11 patients with diverse diagnoses. 52 patients were in NYHA class I and 2 patients were in class II. Most SLV patients had a normal systolic function but median LVEF in patients was lower compared to controls (55.6% vs. 61.2%, p = 0.0001). 2D-CMR-FT demonstrated reduced GLS, GCS and GCSR values in patients compared to controls. LVEF correlated with GS values in patients (p < 0.05). There was no significant difference between GLS values from 2D-CMR-FT and 2D-STE in the patient group. LVEF, LV volumes, GS and GSR (from 2D-CMR-FT) were not significantly different between DILV and TA patients. Although most SLV patients had a preserved EF derived by CMR, our results suggest that, LV deformation and function may behave differently in SLV patients compared to healthy subjects.