Influence of RV Restrictive Physiology on LV Diastolic Function in Children after Tetralogy of Fallot Repair

Evaluation and Management of Chronic Heart Failure in Children and Adolescents With Congenital Heart Disease: A Scientific Statement From the American Heart Association

With continued medical and surgical advancements, most children and adolescents with congenital heart disease are expected to survive to adulthood. Chronic heart failure is increasingly being recognized as a major contributor to ongoing morbidity and mortality in this population as it ages, and treatment strategies to prevent and treat heart failure in the pediatric population are needed. In addition to primary myocardial dysfunction, anatomical and pathophysiological abnormalities specific to various congenital heart disease lesions contribute to the development of heart failure and affect potential strategies commonly used to treat adult patients with heart failure. This scientific statement highlights the significant knowledge gaps in understanding the epidemiology, pathophysiology, staging, and outcomes of chronic heart failure in children and adolescents with congenital heart disease not amenable to catheter-based or surgical interventions. Efforts to harmonize the definitions, staging, follow-up, and approach to heart failure in children with congenital heart disease are critical to enable the conduct of rigorous scientific studies to advance our understanding of the actual burden of heart failure in this population and to allow the development of evidence-based heart failure therapies that can improve outcomes for this high-risk cohort.

Tetralogy of Fallot in Low- and Middle-Income Countries

Low- and middle-incomes countries (LMICs) have limited resources for the diagnosis and treatment of congenital heart diseases such as tetralogy of Fallot. This is in part due to lack of infrastructures, financial means, and expertise. As a result, patients undergo surgery much later than in high-income countries. This delay in treatment results in right ventricular dysfunction, cardiac arrhythmias, and poor psychomotor development-complications that are all related to chronic hypoxia. There are limited data and a few small studies of patients treated for tetralogy of Fallot in LMICs, and, therefore, the aim of this review is to analyse and summarize the surgical outcomes of this LMIC population.

Utility of portal vein pulsatility fraction in patients undergoing corrective surgery for tetralogy of Fallot

BACKGROUND

Right ventricle dysfunction is common after corrective surgery for tetralogy of Fallot and is associated with significant morbidity and mortality. We aimed to determine whether an increased portal vein pulsatility fraction (PVPF) was associated with worse clinical outcomes.

METHODS

In a prospective, observational, single-centre study, PVPF and other commonly used parameters of right ventricle function were assessed in patients of all ages undergoing corrective surgery for tetralogy of Fallot intraoperatively, with transesophageal echocardiography, before and after bypass, and post-operatively, with transthoracic echocardiography, at days 1, 2, at extubation, and at ICU discharge. The correlation was tested between PVPF and mechanical ventilation duration, prolonged ICU stay, mortality, and right ventricle function.

RESULTS

The study included 52 patients, and mortality was in 3 patients. PVPF measurement was feasible in 96% of the examinations. PVPF in the immediate post-operative period had sensitivity of 73.3% and a specificity of 74.3% in predicting the occurrence of the composite outcome of prolonged mechanical ventilation, ICU stay, or mortality. There was a moderate negative correlation of PVPF with right ventricle fractional area change and right ventricle global longitudinal strain (r = -0.577, p < 0.001 and r = 0.465, p < 0.001, respectively) and a strong positive correlation with abnormal hepatic vein waveform (rho = 0.749, p < 0.001).

CONCLUSION

PVPF is an easily obtainable bedside parameter to assess right ventricular dysfunction and predict prolonged mechanical ventilation, prolonged ICU stay, and mortality.

Echocardiographic Assessment of Right Ventricular Function in Paediatric Heart Disease: A Practical Clinical Approach

As the right ventricle (RV) plays an integral role in different paediatric heart diseases, the accurate assessment of RV size and function is essential in the diagnosis, management, and prognostication of congenital and acquired cardiac lesions. Yet, echocardiographic evaluation of the RV is challenging because of its complex and variable morphology, its different physiology compared with the left ventricle, and its capability to adapt to different loading conditions associated with congenital and acquired heart diseases within certain ranges. Reliable echocardiographic detection of RV systolic and diastolic dysfunction remains challenging while important for patient management. This review provides an updated, practical approach to assessing RV function in structurally normal hearts and in children with common congenital heart defects and in those with pulmonary hypertension. We also review the impact of tricuspid valve function on RV functional parameters. There is no single functional RV parameter that uniquely describes RV function; instead a combination of different parameters is recommended in clinical practice. Qualitative and quantitative analysis of RV function will be reviewed including more recent techniques such as speckle tracking and 3D echocardiography.

End-Diastolic Forward Flow and Restrictive Physiology in Repaired Tetralogy of Fallot: A Systematic Review and Meta-Analysis

Background

Pulmonary arterial end‐diastolic forward flow (EDFF) following repaired tetralogy of Fallot has been thought to represent right ventricular (RV) restrictive physiology, but is not fully understood. This systematic review and meta‐analysis sought to clarify its physiological and clinical correlates, and to define a framework for understanding EDFF and RV restrictive physiology.

Methods and Results

PubMed/MEDLINE, Embase, Scopus, and reference lists of relevant articles were searched for observational studies published before March 2021. Random‐effects meta‐analysis was performed to identify factors associated with EDFF. Forty‐two individual studies published between 1995 and 2021, including a total of 2651 participants (1132 with EDFF; 1519 with no EDFF), met eligibility criteria. The pooled estimated prevalence of EDFF among patients with repaired tetralogy of Fallot was 46.5% (95% CI, 41.6%–51.3%). Among patients with EDFF, the use of a transannular patch was significantly more common, and their stay in the intensive care unit was longer. EDFF was associated with greater RV indexed volumes and mass, as well as smaller E‐wave velocity at the tricuspid valve. Finally, pulmonary regurgitation fraction was greater in patients with EDFF, and moderate to severe pulmonary regurgitation was more common in this population.

Conclusions

EDFF is associated with dilated, hypertrophied RVs and longstanding pulmonary regurgitation. Although several studies have defined RV restrictive physiology as the presence of EDFF, our study found no clear indicators of poor RV compliance in patients with EDFF, suggesting that EDFF may have multiple causes and might not be the precise equivalent of RV restrictive physiology.

Density of aortopulmonary collaterals predicts in-hospital outcome in tetralogy of Fallot with pulmonary stenosis

OBJECTIVES

The aim of this study was to characterize the anatomy of aortopulmonary collateral (APC) arteries in tetralogy of Fallot and pulmonary stenosis and to determine whether APC density identified on preoperative multidetector cardiac computed tomography predicts in-hospital outcome.

METHODS

The retrospective single-centre study includes consecutive 135 (2015-2019) patients who underwent one-stage repair. Preoperative multidetector cardiac computed tomography, echocardiography and clinical outcomes were reviewed. The cut-off value of indexed total distal APC cross-sectional area (APC-CSA) was identified by receiver operating characteristic curve. Logistic regression was used for predictors analysis.

RESULTS

The median age and body weight were 19.7 (10.1-89.7) months and 10 (8.3-18) kg. A total of 337 APCs were detected with only one demonstrating severe stenosis. There was a strong and significant correlation between mean APC diameter per patient and age (r = 0.70, P < 0.001). APCs were imaged but mainly received no interventions. In-hospital mortality was similar between patients with high (indexed APC-CSA ≥3.0 mm2/m2) and low (<3.0 mm2/m2) APC density (P = 0.642). Significantly greater patients with high indexed APC-CSA experienced the in-hospital composite outcome of death, arrest, renal/hepatic injury, lactic acidosis or extracorporeal membrane oxygenation (P = 0.007). High APC density was associated with greater dosing (P = 0.008) and longer (P = 0.01) use of inotropic support, prolonged pleural drainage (P = 0.013), longer ventilation (P = 0.042), intensive care unit (P = 0.014) and hospital (P = 0.027) duration. No reintervention and death occurred in the follow-up with the median duration of 24.4 (11-36.6) months. Multivariable analysis showed the Nakata index (P = 0.05) and high APC density (P = 0.02) independently predicted the composite outcome.

CONCLUSIONS

In tetralogy of Fallot and pulmonary stenosis, APCs are likely to be dilated bronchial arteries. Preoperative multidetector cardiac computed tomography-derived APC density was as important as Nakata index in predicting the occurrence of in-hospital composite outcome. The APC-CSA of 3.0 mm2/m2 maybe considered as a threshold for risk stratification.

Evolution of echocardiography in adult congenital heart disease: from pulsed-wave Doppler to fusion imaging

The number of patients with adult congenital heart disease (ACHD) has been dramatically increasing and adults with congenital heart disease now outnumber children with congenital heart disease. However, patients with ACHD are still at increased risk of morbidity and mortality due to residua and sequelae. Although echocardiography is an indispensable imaging modality in the comprehensive assessment of ACHD, accurate echocardiographic assessment of ACHD is challenging especially for physicians or sonographers who are not familiar with ACHD because of its complex morphology, physiology, and hemodynamics. A recently developed fusion imaging technology can provide synchronized display of real-time echocardiographic images and multiplanar reconstruction images of computed tomography or magnetic resonance imaging corresponding to the image plane of real-time echocardiography. We have reported the clinical utility of this fusion imaging technology for the precise evaluation of complex ACHD. On the other hand, conventional echocardiographic technology also plays an important role in assessing unique ACHD pathophysiology. For example, restrictive right ventricular physiology is a common finding after tetralogy of Fallot or pulmonary stenosis repair and can be evaluated by conventional pulsed-wave Doppler. In this review, we discuss the clinical usefulness of modern and conventional echocardiographic technologies for the evaluation of ACHD by presenting a case series.

Heart failure with reduced and preserved ejection fraction in adult congenital heart disease

Heart failure with reduced ejection fraction (HFrEF) is common in patients with adult congenital heart disease. Many of the most common congenital defects have a high prevalence of HFrEF, including left-sided obstructive lesions (aortic stenosis, coarctation of the aorta, Shone complex), tetralogy of Fallot, Ebstein anomaly, lesions in which there is a systemic right ventricle, and lesions palliated with a Fontan circulation. However, heart failure with preserved ejection fraction (HFpEF) is also prevalent in all these lesions. Comprehensive evaluation includes physical exam, biomarkers, echocardiography and advanced imaging, exercise stress testing, and, in some cases, invasive hemodynamics. Guideline-directed medical therapy for HFrEF can be applied to left-sided lesions and may be considered on an individual basis for systemic right ventricle and single-ventricle patients. Medical therapy is limited for HFpEF. However, in both HFrEF and HFpEF, ventricular dyssynchrony and arrhythmias play an important role, and medications for rhythm control, ablation, and cardiac resynchronization therapy should be considered. Finally, aggressive management of cardiovascular risk factors and comorbidities, including, but not limited to, hypertension, obesity, diabetes, dyslipidemia, and obstructive sleep apnea, cannot be overemphasized.

Heart failure in adult congenital heart disease: tetralogy of Fallot

The number of rTOF patients who survive into adulthood is steadily rising, with currently more than 90% reaching the third decade of life. However, rTOF patients are not cured, but rather have a lifelong increased risk for cardiac and non-cardiac complications. Heart failure is recognized as a significant complication. Its occurrence is strongly associated with adverse outcome. Unfortunately, conventional concepts of heart failure may not be directly applicable in this patient group. This article presents a review of the current knowledge on HF in rTOF patients, including incidence and prevalence, the most common mechanisms of heart failure, i.e., valvular pathologies, shunt lesions, left atrial hypertension, primary left heart and right heart failure, arrhythmias, and coronary artery disease. In addition, we will review information regarding extracardiac complications, risk factors for the development of heart failure, clinical impact and prognosis, and assessment possibilities, particularly of the right ventricle, as well as management strategies. We explore potential future concepts that may stimulate further research into this field.

Quantification of end diastolic forward flow in two cases with pulmonary atresia with intact ventricular septum

Similar to patients with repaired tetralogy of Fallot, patients with repaired pulmonary atresia with intact ventricular septum may need a reintervention at a later stage. Although the role of MRI in the long-term follow-up of patients with repaired tetralogy of Fallot has been established, the same has not been established for patients with repaired pulmonary atresia with intact ventricular septum. To define this role, we quantified the end-diastolic forward flow by fractioning it by the total flow of the main pulmonary artery in two cases during their long-term follow up after biventricular repair. In case 1, a male patient had hepatic congestion and a high end-diastolic forward flow fraction and underwent surgical take down to one and one-half ventricle repair at the age of 18 years. In case 2, a female patient, currently 13 years old, has an increasing end-diastolic forward flow fraction. She is under close observation as a potential candidate for one and one-half ventricle repair in the near future. Both patients had a high end-diastolic forward flow fraction of the total right ventricle output, suggesting that end-diastolic forward flow fraction may become a possible become a possible indicator of the adequacy of biventricular repair and the optimal timing for re-intervention.

Relationship between right and left ventricular diastolic dysfunction assessed by 2-dimensional speckle-tracking echocardiography in adults with repaired tetralogy of Fallot

Several studies have reported a correlation between right ventricular (RV) and left ventricular (LV) systolic dysfunction in adults with repaired tetralogy of Fallot (TOF). However, data are lacking regarding the relationship between RV and LV diastolic dysfunction assessed by 2-dimensional speckle-tracking echocardiography. We studied 69 adults with repaired TOF (mean age 34 years, 61% male) who had been regularly followed up and had routinely undergone echocardiography. In addition to conventional echocardiography, global longitudinal strain (GLS) and early diastolic strain rate (SRe) of both ventricles were assessed using 2-dimensional speckle-tracking echocardiography. Results were compared with 30 age- and sex-matched controls. RV and LV GLS were decreased in TOF patients compared with controls (− 18.4 ± 3.3% vs. −23.5 ± 4.2%, p < 0.001 and − 16.0 ± 3.8% vs. −20.0 ± 3.0%, p < 0.001, respectively). RV and LV SRe were also decreased in TOF patients compared with controls (1.22 ± 0.34 sec^− 1 vs. 1.47 ± 0.41 sec^− 1, p = 0.003 and 1.29 ± 0.42 sec^− 1 vs. 1.63 ± 0.42 sec^− 1, p < 0.001, respectively). A correlation between RV and LV SRe was found in TOF patients (r = 0.43, p < 0.001) as well as between RV and LV GLS (r = 0.45, p < 0.001). Two-dimensional speckle-tracking echocardiography reveals subclinical RV and LV diastolic dysfunction in adults with repaired TOF. A correlation is observed between RV and LV diastolic dysfunction as well as between RV and LV systolic dysfunction.

Echocardiographic predictors of elevated left ventricular end diastolic pressure in adolescent and adult patients with repaired tetralogy of Fallot

Elevated left ventricular end diastolic pressure is a risk factor for ventricular arrhythmias in patients with tetralogy of Fallot. The objective of this retrospective study was to identify echocardiographic measures associated with left ventricular end diastolic pressure >12 mmHg in this population. Repaired tetralogy of Fallot patients age ≥13 years, who underwent a left heart catheterisation within 7 days of having an echocardiogram were evaluated. Univariate comparison was made in echocardiographic and clinical variables between patients with left ventricular end diastolic pressure >12 versus ≤12 mmHg. Ninety-four patients (54% male) with a median age of 24.6 years were included. Thirty-four (36%) had left ventricular end diastolic pressure >12 mmHg. Patients with left ventricular end diastolic pressure >12mmHg were older (median 32.9 versus 24.0 years, p = 0.02), more likely to have a history of an aortopulmonary shunt (62% versus 38%, p = 0.03), and have a diagnosis of hypertension (24% versus 7%, p = 0.03) compared to those with left ventricular end diastolic pressure ≤12 mmHg. There were no significant differences in mitral valve E/A ratio, annular e' velocity, or E/e' ratio between patients with left ventricular end diastolic pressure >12 versus ≤12 mmHg. Patients with left ventricular end diastolic pressure >12mmHg had larger left atrial area (mean 17.7 versus 14.0 cm2, p = 0.03) and larger left atrium anterior-posterior diameter (mean 36.0 versus 30.6 mm, p = 0.004). In conclusion, typical echocardiographic measures of left ventricular diastolic dysfunction may not be reliable in tetralogy of Fallot patients. Prospective studies with the use of novel echocardiographic measures are needed.

Etiology of right ventricular restrictive physiology early after repair of tetralogy of Fallot in pediatric patients

BACKGROUND

Right ventricular restrictive physiology (RVRP) is a common finding after repair of Tetralogy of Fallot (TOF). The characteristic feature of RVRP is the presence of a direct end-diastolic flow (EDFF) during atrial contraction in the main pulmonary artery. This end-diastolic forward flow is caused by increased right ventricular end-diastolic pressure due to right ventricular myocardial stiffness and decreased right ventricular compliance.

OBJECTIVE

Our main objective is to found out the etiology of RVRP in pediatrics patients who underwent for complete repair of Tetralogy of Fallot (TOF).

METHODS

A total of 50 TOF patients have registered for this study in our hospital from January 2017 to September 2018. The patients were divided in two groups, group A with restrictive physiology and group B without restrictive physiology. The patients selected for this study includes TOF patients, TOF patients with atrial septal defect (ASD), and TOF patients with patent ductus arteriosus (PDA). Ventricular hypertrophy and right heart enlargement were evaluated by electrocardiogram and echocardiography. The other parameters we used to compare between these two groups were sex, age, weight, cardio pulmonary bypass (CPB) time, aortic cross clamping time, transannular patch, SP0₂, RV/LV pressure, ventricular hypertrophy, right heart (RH) enlargement, tricuspid annular plane systolic excursion (TAPSE), pulmonary artery systolic pressure (PASP), TAPSE/PASP ratio, pulmonary annular diameter, intubation time, PICU stay and hematocrit (HCT).

RESULTS

RVRP was identified in 28 patients (58%). Lower SP0₂ (mean: 84.3 ± 7.9%) with p-value 0.015, transannular patch repair (n = 22, 78.5%) with p-value< 0.001, longer cardiopulmonary bypass (CPB) time (mean: 117.6 ± 23 min) with p-value< 0.001, longer aortic cross clamping time (mean: 91.4 ± 20.26 min) with p-value< 0.001, lower TAPSE, lower PASP,lower TAPSE/PASP ratio and presence of hypertrophy (p-value < 0.001) were identified as etiology for restrictive physiology. It was also found that 77% TOF patients with ASD have a higher risk of RVRP in our study.

CONCLUSIONS

In TOF patient's etiology for right ventricular restrictive physiology are associated with lower SP0_2, transannular patch repair, longer CPB and longer aortic cross clamping time, hypertrophy, lower TAPSE, lower PASP and lower TAPSE/PASP ratio.

A Case Report Examining Early Extubation Following Congenital Heart Surgery in a Low Resource Setting

This case report aims to critically analyse the evidence surrounding early extubation in the post-operative phase following complex congenital cardiac surgery. Child A was an 8 year old female who had undergone complex congenital cardiac surgery during an international surgical charity mission. On admission to the paediatric intensive care unit Child A appeared to be in good condition and no major complications had occurred intra-operatively. This was considered alongside the situational pressures of resource limitations and the mission's aim to offer surgery to as many children as possible during the available time frame. The decision was made by the team that Child A was a suitable candidate for 'early extubation.' Some members of the team were uncomfortable with this approach and felt it could lead to poorer outcomes for patients. Current evidence surrounding early extubation both within international surgical mission trips to low-income and middle-income countries and established cardiac centres within high-income countries is examined and discussed alongside the context of resource limitation. Although the process and implications of early extubation following cardiac surgery needs further research, on the basis of the evidence currently available clinicians could potentially encourage the use of early extubation within clinical practice (for appropriately selected patients) through the utilisation of a multidisciplinary approach, both within the UK and during international surgical charity missions to low-income and middle-income countries.

Severe right ventricular dilatation after repair of Tetralogy of Fallot is associated with increased left ventricular preload and stroke volume

Aims

Pulmonary regurgitation (PR) and right ventricular (RV) dilatation are common in repaired tetralogy of Fallot (rTOF). Left ventricular (LV) dysfunction is an important risk factor in rTOF. The effect of PR/RV dilatation on LV performance and RV-LV interactions in rTOF are incompletely understood. We examined LV responses and exercise capacity in rTOF, both before and after pulmonary valve replacement (PVR).

Methods and results

Cardiac magnetic resonance imaging scans in 126 rTOF patients (age 17.3 ± 7.6 years) were analysed, comparing subjects with indexed RV end-diastolic volume (RVEDVi) <170 mL/m2 (mild/moderate dilatation, n = 95) and RVEDVi ≥170 mL/m2 (severe dilatation, n = 31). Indexed PR volume (PRVi), RV end-systolic (RVESVi), RV end-diastolic (RVEDVi), RV stroke volume (RVSVi), net pulmonary forward flow (NPFFi), LV end-diastolic (LVEDVi), LV end-systolic (LVESVi), LV stroke volume (LVSVi), RV and LV ejection fraction (EF), and diastolic septal curvature were obtained. Peak aerobic capacity (VO2 max) was measured. In a subset (n = 30), measures were obtained pre-and-post surgical PVR. Compared to those with mild/moderate RV dilatation, patients with severe RV dilation had greater PRVi (38 ± 12 vs. 24 ± 9 mL/m2, P < 0.0001), NPFFi (53 ± 9 vs. 44 ± 11 mL/m2, P < 0.0001), LVEDVi (87 ± 14 vs. 73 ± 13 mL/m2, P < 0.0001), LVESVi (39 ± 12 vs. 30 ± 8 mL/m2, P < 0.0001), and LVSVi (48 ± 7 vs. 43  ±  8 mL/m2, P = 0.002) but lower RV ejection fraction (46 ± 8 vs. 53 ± 7%, P < 0.0001). Septal curvature and VO2 max were similar in both groups. After PVR, there was no change in LVEDVi, LVSVi, septal curvature, or VO2 max.

Conclusions

Chronic PR with severe RV dilatation is associated with increased NPFFi, LVEDVi, and LVSVi. This may potentially explain preserved exercise capacity in rTOF with severe PR and RV dilatation.

Abnormalities in Left Ventricular Rotation Are Inherent in Young Children with Repaired Tetralogy of Fallot and Are Independent of Right Ventricular Dilation

Left ventricular (LV) dysfunction is a risk factor for adverse outcomes in older children and adults with repaired Tetralogy of Fallot (rToF). Pulmonary regurgitation (PR), right ventricular (RV) dilation, and dysfunction have been shown to result in abnormal LV myocardial mechanics and dysfunction. The aim of our study was to evaluate LV rotational mechanics, especially apical rotation in young children with rToF with and without RV dilation. This is a retrospective, single center study in 28 asymptomatic young children with rToF (16 with RV dilation; 12 without RV dilation); 29 age-matched normal controls. RV and LV systolic and diastolic function was studied using conventional two-dimensional echocardiography (2DE) and speckle tracking echocardiography (STE). Rotational mechanics studied included basal and apical rotation (BR, AR), peak twist (calculated by difference between the apical and basal rotation), twist rate (TR), and untwist rate (UnTR). The mean age of the cohort was 4.7 years (± 2.3). Abnormal AR, BR, TR, and UnTR were noted in patients with rToF. The abnormalities were significant in magnitude as well as the direction of rotation; more pronounced in the absence of RV dilation. LV systolic and diastolic dysfunction as evidenced by abnormal AR and degree of untwist is inherent in rToF and not associated with RV dilation in rToF children. Abnormal BR may reflect a lack of maturation to adult type of rotational mechanics. Further longitudinal studies are required to study the progression of these abnormalities and their correlation with clinical outcomes.

Usefulness of Pulmonary Arterial End-Diastolic Forward Flow Late After Tetralogy of Fallot Repair to Predict a "Restrictive" Right Ventricle

The functional significance of pulmonary arterial end-diastolic forward flow (EDFF) in patients with repaired tetralogy of Fallot (rTOF) is not fully understood, with conflicting reports regarding its associations with pulmonary regurgitation (PR), right ventricular (RV) size and function, and so-called restrictive RV physiology. To examine these associations, we retrospectively analyzed 399 patients with rTOF who had contemporaneous echocardiography (Echo) and cardiovascular magnetic resonance (CMR) studies. The median age at TOF repair was 0.7 years (0.21, 2.66), age at CMR was 19.8 years (13.0, 29.4), and interval between Echo and CMR was 48 days (0, 182). Doppler identified EDFF in 122 (31%) patients and CMR in 113 patients (28%). Compared with those without EDFF, patients with EDFF were younger, had greater PR, and higher RV end-diastolic volume, stroke volume, and ejection fraction. Markers of RV restriction such as right atrial size did not differ between groups. On multivariable regression, EDFF was associated with higher RV stroke volume and lower left ventricular end-diastolic volume. The association between Echo and CMR measurements of EDFF was modest (area under the receiver operating characteristic curve = 0.684, r = 0.374, p < 0.001). In conclusion, EDFF was common in this large cohort of patients with rTOF, but its presence and extent varied between Echo and CMR. EDFF was associated with greater PR and larger RV size, but not with markers of poor RV compliance such as right atrial enlargement. Mechanisms beyond RV noncompliance may contribute to the presence of EDFF.

Assessment of Diastolic Function in Congenital Heart Disease

Diastolic function is an important component of left ventricular (LV) function which is often overlooked. It can cause symptoms of heart failure in patients even in the presence of normal systolic function. The parameters used to assess diastolic function often measure flow and are affected by the loading conditions of the heart. The interpretation of diastolic function in the context of congenital heart disease requires some understanding of the effects of the lesions themselves on these parameters. Individual congenital lesions will be discussed in this paper. Recently, load-independent techniques have led to more accurate measurements of ventricular compliance and remodeling in heart disease. The combination of inflow velocities and tissue Doppler measurements can be used to estimate diastolic function and LV filling pressures. This review focuses on diastolic function and assessment in congenital heart disease.

Echocardiography in the Assessment of Left Atrial Pressure After Pediatric Heart Surgery: A Comparison Study With Measurements Obtained From Left Atrial Catheter

BACKGROUND

Correlation between ventricular end-diastolic pressure and pulsed Doppler and tissue Doppler-derived E/e' ratio has been widely reported in adults but scarcely studied in children with congenital heart diseases. This ratio is defined as the relationship between diastolic transmitral flow velocity (cm/s; E) and myocardial diastolic relaxation velocity (cm/s; e') in the lateral aspect of the mitral annulus. Our main objective was to ascertain whether a correlation existed between direct measurement of left atrial pressure and echocardiographic E/e' ratio in children after heart surgery.

METHODS

Prospective study including 27 consecutive children after pediatric heart surgery. Data were analyzed according to whether they were obtained within the first 72 hours following surgery or later on. Sensitivity, specificity, positive and negative predictive values, and areas under the receiver-operating characteristics curve of E/e' ratio in detection of left atrial pressure values ≥13 mm Hg were evaluated.

RESULTS

Forty-eight studies were conducted in 27 patients. Thirty-two studies were performed during the first 72 hours after heart surgery and 16 beyond the third day. Median patient age was 0.82 years (5 days-16 years). Median left atrial pressure values and E/e' measurements of the whole cohort (N = 48) were 12.0 and 10.2, respectively. Intraclass correlation index between left atrial pressure values and echocardiographic E/e' ratio was 0.35, 0.25 for studies performed within 72 hours, but 0.78 (P < .01) for those performed later. There was also a high positive predictive value, since in 13 (87%) of 15 studies with an E/e' ratio ≥13, the left atrial pressure was ≥13 mm Hg.

CONCLUSION

While echocardiographic E/e' ratio did not show a good correlation with left atrial pressure in the immediate postoperative period, the positive predictive value may suffice to aid clinicians in predicting elevated pressures.

Echocardiographic Parameters of Right Ventricular Diastolic Function in Repaired Tetralogy of Fallot Are Associated with Important Findings on Magnetic Resonance Imaging

BACKGROUND

Right ventricular (RV) dilation, RV dysfunction, RV outflow tract obstruction, and branch pulmonary artery stenosis are risk factors associated with the need for future surgical or catheter-based intervention commonly assessed by cardiac magnetic resonance in patients with tetralogy of Fallot who have undergone initial repair. The ability of echocardiography to predict the presence of these risk factors is limited.

OBJECTIVE

We aimed to determine the association between echocardiographic parameters of right ventricular diastolic dysfunction and risk factors for intervention as identified on cardiac magnetic resonance imaging (CMR).

DESIGN

We reviewed all echocardiograms and CMRs performed at our institution within 1 year of each other in patients with repaired tetralogy of Fallot. We evaluated patients for the following: RV systolic dysfunction (RV ejection fraction <45%), RV dilation (right ventricular end-diastolic volume ≥ 160 mL/m(2)), and RV obstruction (RV outflow tract gradient ≥ 3 m/s by echocardiogram or branch pulmonary artery stenosis assessed by CMR). We evaluated for associations between the above CMR findings and echocardiographic parameters of diastolic function.

RESULTS

CMR and echocardiographic images performed between March 2007 and March 2012 were available in 99 patients. RV obstruction was associated with lower E/A ratio (P = .02), E/A reversal (P = .02), and prograde end diastolic pulmonary flow (P < .01). Low tricuspid annular a' and low septal s' were associated with lower RV ejection fraction (P < .01, P < .01). Elevated E/e' was associated with higher RV end diastolic volume (P = .04). In predicting the presence of any of the evaluated risk factors for future intervention, TV E/e' ≥ 4.7 had positive predictive value (PPV) of 86% and negative predictive value (NPV) of 50%, TV E/A reversal had PPV of 89% and NPV of 34, and prograde end diastolic pulmonary flow on echocardiogram had PPV of 91% and NPV of 38%.

CONCLUSIONS

Echocardiographic parameters of diastolic dysfunction have a reasonable PPV but poor NPV for predicting clinically significant risk factors identified by CMR.

Factors associated with in utero demise of fetuses that have underlying cardiac pathologies

Factors associated with in utero fetal demise (IUFD) of fetuses that have underlying cardiac pathologies are largely unknown. This case-control study aimed to define the prevalence of IUFD in fetuses with a diagnosis of cardiac pathologies and to identify prenatal predictors of IUFD. Between January 2004 and December 2010, 74 IUFD cases [4.6 %; 95 % confidence interval (CI) 3.7-5.8 %] were identified from 1,584 cases with a diagnosis of structural or functional cardiac lesions in the Hospital for Sick Children database. The cases were divided into right-sided (N = 28), left-sided (N = 23), great artery (N = 8), and miscellaneous (N = 15) groups. The control subjects (1:1 ratio) were fetuses that had cardiac pathology diagnosed within 48 h of the IUFD case. Multivariable regression models were used to determine echocardiographic predictors of IUFD. The prevalence of IUFD was greatest in hypertrophic cardiomyopathy (8/16, 50 %) and Ebstein's anomaly/tricuspid dysplasia (4/15, 27 %) and lowest in transposition of the great arteries (2/85, 1 %). The findings showed IUFD to be associated with hydrops in 17 (23 %) of the 74 cases and arrhythmia in 11 (15 %) of the 74 cases. The factors identified by univariable logistic regression analyses were right ventricular dysfunction [odds ratio (OR) 2.7; p = 0.001], left ventricular dysfunction (OR 1.8; p = 0.007), umbilical vein pulsations (OR 10.9; p = 0.002), and abnormal ductus venosus flow (OR 3.3; p = 0.01). The factors associated with IUFD in multivariable logistic regression models were cardiomegaly (OR 5.6; p = 0.01), hydrops (OR 29.5; p = 0.001), pericardial effusion (OR 4.1; p = 0.06), and extracardiac abnormalities (OR 7.2; p < 0.001). The prevalence of IUFD is greatest in conditions affecting the ventricular myocardium. The onset of IUFD appears to be related initially to right ventricular dysfunction. Closer surveillance is recommended for lesions at risk of IUFD.

Impact of obesity on ventricular size and function in children, adolescents and adults with Tetralogy of Fallot after initial repair

Obesity is epidemic in congenital heart disease, with reported rates of 16% to 26% in children and 54% in adults. The aim of this study was to evaluate the impact of obesity on ventricular function and size in patients after initial repair for tetralogy of Fallot (TOF). Cardiac magnetic resonance studies in normal-weight (body mass index percentile <85th) and obese (body mass index percentile ≥95th) children and adults with repaired tetralogy of Fallot were reviewed. The left ventricular ejection fraction, the right ventricular ejection fraction, left and right ventricular end-diastolic volumes indexed to actual body surface area, to height, and to body surface area using ideal body weight were evaluated in 36 obese patients and 72 age-matched normal-weight patients. Compared with normal-weight patients, obese patients had lower right ventricular ejection fractions (mean 46 ± 9% vs 51 ± 7%, p = 0.003) and left ventricular ejection fractions (mean 57 ± 9% vs 61 ± 6%, p = 0.017), higher right ventricular end-diastolic volumes indexed to height (mean 160 ± 59 vs 135 ± 41 ml/m, p = 0.015) and left ventricular end-diastolic volumes indexed to height (mean 86 ± 25 vs 70 ± 20 ml/m, p = 0.001), and higher right ventricular end-diastolic volumes indexed to ideal body weight (mean 166 ± 55 vs 144 ± 38 ml/m², p = 0.020) and left ventricular end-diastolic volumes indexed to ideal body weight (mean 90 ± 22 vs 75 ± 15 ml/m², p <0.001). In conclusion, obesity is a modifiable risk factor associated with worsened biventricular systolic function and biventricular dilation in patients with repaired tetralogy of Fallot. The standard method of indexing ventricular volumes using actual body surface area may underestimate volume load in obese patients.