Echocardiographic examination of mitral valve abnormalities in the paediatric population: current practices

Assessment of Heart Rate Variability in Children with Mitral Valve Prolapse

BACKGROUND

Mitral valve prolapse (MVP) is a heart valve anomaly with specific electrocardiographic findings and arrhythmia. A predominant sympathetic tone and diminished vagal activity have been reported especially in symptomatic MVP patients.

OBJECTIVES

In the current study, we aim to review heart rate variability (HRV) parameters of MVP children in order to determine if there is an impaired autonomic regulation.

METHODS

The data of children with MVP were retrospectively analyzed. Demographic characteristics, body mass index, symptomatology, MVP type and mitral regurgitation, MVP-related electrocardiographic changes, arrhythmia, and HRV parameters in 24-h Holter monitoring were recorded. HRV parameters of the control group were obtained from children applying for sport participation. Statistical significance limit was accepted as p < 0.05.

RESULTS

154 of the patients (74.8%) were girls, the median age was 13.58 ± 2.99 years. While MVP patients had shorter PR intervals, those who had syncope had longer PR intervals. Short PR distance may be a feature of MVP, long PR distance may be a condition associated with syncope with the underlying paroxysmal atrioventricular block. Moreover, the minimum heart rate was significantly lower in the MVP group compared to the control and there were no significant differences in terms of remaining parameters. The number of low LF values was higher in MVP patients than the control. Comparing HRV values of groups by gender, we found that overall HRV parameters were lower in girls with MVP while minimum, maximum, and average heart rate were lower in boys with MVP.

CONCLUSION

Impaired HRV associated with MVP could be age, gender, and symptom related. In addition, low LF may indicate impaired baroreflex sensitivity in MVP patients.

Clinical and 2D/3D-Echo Cardiography Determinants of Mitral Valve Reoperation in Children With Congenital Mitral Valve Disease

Background

Congenital mitral valve disease (CMVD) presents major challenges in its medical and surgical management.

Objectives

The purpose of this study was to investigate the value of 3-dimensional echocardiography (3DE) and identify associations with MV reoperation in this setting.

Methods

All children <18 years of age who underwent MV reconstruction for CMVD in 2002 to 2018 were included. Preoperative and postoperative 2-dimensional echocardiography (2DE) and 3DE data were collected. Competing risks and Cox regression analysis were used to identify independent associations with MV reoperation. Receiver operating characteristic and decision-tree analysis were implemented for comparison of 3DE vs 2DE.

Results

A total of 206 children underwent MV reconstruction for CMVD (mitral stenosis, n = 105, mitral regurgitation [MR], n = 75; mixed disease, n = 26); 64 (31%) required MV reoperation. Variables independently associated with MV reoperation were age <1 year (HR: 2.65; 95% CI: 1.13-6.21), tethered leaflets (HR: 2.00; 95% CI: 1.05-3.82), ≥ moderate 2DE postoperative MR (HR: 4.26; 95% CI: 2.45-7.40), changes in 3D-effective orifice area (3D-EOA) and in 3D-vena contracta regurgitant area (3D-VCRA). Changes in 3D-EOA and 3D-VCRA were more strongly associated with MV reoperation than changes in mean gradients (area under the curve [AUC]: 0.847 vs AUC: 0.676, P = 0.006) and 2D-VCRA (AUC: 0.969 vs AUC: 0.720, P = 0.012), respectively. Decision-tree analysis found that a <30% increase in 3D-EOA had 80% accuracy (HR = 8.50; 95% CI: 2.9-25.1) and a <40% decrease in 3D-VCRA had 93% accuracy (HR: 22.50; 95% CI: 2.9-175) in discriminating MV reoperation for stenotic and regurgitant MV, respectively.

Conclusions

Age <1 year, tethered leaflets, 2DE postoperative MR, changes in 3D-EOA and 3D-VCRA were all independently associated with MV reoperation. 3DE parameters showed a stronger association than 2DE. 3DE-based decision-tree algorithms may help prognostication and serve as a support tool for clinical decision-making.

Guidelines for Performing a Comprehensive Pediatric Transthoracic Echocardiogram: Recommendations From the American Society of Echocardiography

Echocardiography is a fundamental component of pediatric cardiology, and appropriate indications have been established for its use in the setting of suspected, congenital, or acquired heart disease in children. Since the publication of guidelines for pediatric transthoracic echocardiography in 2006 and 2010, advances in knowledge and technology have expanded the scope of practice beyond the use of traditional modalities such as two-dimensional, M-mode, and Doppler echocardiography to evaluate the cardiac segmental structures and their function. Adjunct modalities such as contrast, three-dimensional, and speckle-tracking echocardiography are now used routinely at many pediatric centers. Guidelines and recommendations for the use of traditional and newer adjunct modalities in children are described in detail in this document. In addition, suggested protocols related to standard operations, infection control, sedation, and quality assurance and improvement are included to provide an organizational structure for centers performing pediatric transthoracic echocardiograms.

Left atrioventricular valve repair after primary atrioventricular canal surgery: Predictors of durability

OBJECTIVE

Acute outcomes after atrioventricular canal defects (AVCD) surgery in the current era are excellent; yet despite surgical advances, ∼15% of patients require future left atrioventricular valve (LAVV) repair. Among patients with AVC who undergo LAVV repair after primary AVC surgery, we sought to characterize the durability of these repairs. Specifically, we aimed to determine predictors for reintervention following an LAVV repair in patients with repaired AVCD, with a focus on postoperative transesophageal echocardiography (TEE).

METHODS

We reviewed all patients undergoing LAVV repair (after a primary AVCD surgery) at Boston Children's Hospital between 2010 and 2020. Competing risk analysis was performed to evaluate cumulative incidence of LAVV reinterventions. Predictors of LAVV reintervention were evaluated using multivariable Cox regression.

RESULTS

A total of 137 LAVV repairs following primary AVCD surgery were performed in 113 patients. Median age and weight at LAVV repair were 25 months (interquartile range, 12-76 months) and 11.1 kg (interquartile range, 7.8-19.4 kg). Original anatomy was complete AVCD in 87 (63%), transitional AVCD in 27 (20%), and partial AVCD in 23 (17%) cases. Over a median follow-up of 12 months (interquartile range, 1.3 months-4 years), 47 (34%) of the LAVV repairs required LAVV reintervention. Reinterventions included a total of 27 LAVV re-repairs and 20 LAVV replacements. In multivariable analysis, age at LAVV repair younger than 72 months, partial AVCD anatomy, left ventricle dysfunction, mean LAVV stenosis gradient ≥5 mm Hg, and multiple jets of regurgitation on postoperative LAVV repair TEE were associated with LAVV reintervention. Grade of LAVV regurgitation on postoperative TEE was not an independent risk factor, but reintervention rates were high when residual LAVV stenosis gradient was ≥5 mm Hg and residual mild LAVV regurgitation was present on postoperative TEE (47%) and even higher when residual LAVV stenosis gradient was ≥5 mm Hg and LAVV regurgitation was greater than mild (73%).

CONCLUSIONS

Reintervention rates remain high for LAVV repairs that occur after primary AVCD surgery, particularly for patients with LAVV stenosis gradient ≥5 mm Hg and mild or greater LAVV regurgitation on postoperative TEE.

Echocardiographic Parameters for Risk Prediction in Borderline Right Ventricle: Review with Special Emphasis on Pulmonary Atresia with Intact Ventricular Septum and Critical Pulmonary Stenosis

The aim of the present review is to highlight the strengths and limitations of echocardiographic parameters and scores employed to predict favorable outcome in complex congenital heart diseases (CHDs) with borderline right ventricle (RV), with a focus on pulmonary atresia with intact ventricular septum and critical pulmonary stenosis (PAIVS/CPS). A systematic search in the National Library of Medicine using Medical Subject Headings and free-text terms including echocardiography, CHD, and scores, was performed. The search was refined by adding keywords "PAIVS/CPS", Ebstein's anomaly, and unbalanced atrioventricular septal defect with left dominance. A total of 22 studies were selected for final analysis; 12 of them were focused on parameters to predict biventricular repair (BVR)/pulmonary blood flow augmentation in PAIVS/CPS. All of these studies presented numerical (the limited sample size) and methodological limitations (retrospective design, poor definition of inclusion/exclusion criteria, variability in the definition of outcomes, differences in adopted surgical and interventional strategies). There was heterogeneity in the echocardiographic parameters employed and cut-off values proposed, with difficultly in establishing which one should be recommended. Easy scores such as TV/MV (tricuspid/mitral valve) and RV/LV (right/left ventricle) ratios were proven to have a good prognostic accuracy; however, the data were very limited (only two studies with <40 subjects). In larger studies, RV end-diastolic area and a higher degree of tricuspid regurgitation were also proven as accurate predictors of successful BVR. These measures, however, may be either operator and/or load/pressure dependent. TV Z-scores have been proposed by several authors, but old and heterogenous nomograms sources have been employed, thus producing discordant results. In summary, we provide a review of the currently available echocardiographic parameters for risk prediction in CHDs with a diminutive RV that may serve as a guide for use in clinical practice.

Left Atrioventricular Transvalvular Pressure Gradients Derived from Intraoperative and Postoperative Echocardiograms following Atrioventricular Septal Defect Repair

BACKGROUND

Left atrioventricular valve (LAVV) stenosis following an atrioventricular septal defect (AVSD) repair is a rare but potentially life-threatening complication. While echocardiographic quantification of diastolic transvalvular pressure gradients is paramount in the evaluation of a newly corrected valve function, it is hypothesized that these measured gradients are overestimated immediately following a cardiopulmonary bypass (CPB) due to the altered hemodynamics when compared to postoperative valve assessments using awake transthoracic echocardiography (TTE) upon recovery after surgery.

METHODS

Out of the 72 patients screened for inclusion at a tertiary center, 39 patients undergoing an AVSD repair with both intraoperative transesophageal echocardiograms (TEE, performed immediately after a CPB) and an awake TTE (performed prior to hospital discharge) were retrospectively selected. The mean (MPGs) and peak pressure gradients (PPGs) were quantified using a Doppler echocardiography and other measures of interest were recorded (e.g., a non-invasive surrogate of the cardiac output and index (CI), left ventricular ejection fraction, blood pressures and airway pressures). The variables were analyzed using the paired Student's t-tests and Spearman's correlation coefficients.

RESULTS

The MPGs were significantly higher in the intraoperative measurements when compared to the awake TTE (3.0 ± 1.2 vs. 2.3 ± 1.1 mmHg; p < 0.01); however, the PPGs did not significantly differ (6.6 ± 2.7 vs. 5.7 ± 2.8 mmHg; p = 0.06). Although the assessed intraoperative heart rates (HRs) were also higher (132 ± 17 vs. 114 ± 21 bpm; p < 0.001), there was no correlation found between the MPG and the HR, or any other parameter of interest, at either time-point. In a further analysis, a moderate to strong correlation was observed in the linear relationship between the CI and the MPG (r = 0.60; p < 0.001). During the in-hospital follow-up period, no patients died or required an intervention due to LAVV stenosis.

CONCLUSIONS

The Doppler-based quantification of diastolic transvalvular LAVV mean pressure gradients using intraoperative transesophageal echocardiography seems to be prone to overestimation due to altered hemodynamics immediately after an AVSD repair. Thus, the current hemodynamic state should be taken into consideration during the intraoperative interpretation of these gradients.

Incidental finding of accessory mitral valve tissue on routine adult echocardiography

Accessory mitral valve tissue is a rare congenital cardiac abnormality that sometimes can cause left ventricular outflow tract obstruction. We herein present the case of a 55-year-old male with an incidental finding of accessory mitral valve tissue on transthoracic echocardiography. The patient was managed conservatively as accessory tissue was not causing left ventricular outflow obstruction and there were no hemodynamic consequences.

A narrative review of modern approach and outcomes evaluation in congenital heart defects

OBJECTIVE

The purpose of this review is to highlight critical advances and innovative approaches to the most challenging clinical situations in congenital heart surgery, to establish a new perspective from which to evaluate current clinical practice patterns and contemporary United States program ranking systems.

BACKGROUND

The past decades have witnessed substantial advances in the treatment of congenital heart defects. New strategies are deeply rooted in calculated risk-taking innovations. Pioneer surgeons developed, improved and refined critical operative skills and techniques to optimize cardiovascular physiology, decrease operative mortality and improve clinical outcomes.

METHODS

Unfortunately, in the modern surgical era, supportive environments to allow surgeons to make similar gains and innovative contributions remain scarce. In the current practice, overall procedure volume is prioritized to safeguard quality metrics, including hospital survival and length of stay, surgical complications, and neurocognitive outcomes. As a result, exceptional surgical results have become translated and defined by public ranking systems such as the US News and World Report Best Children's Hospital National Ranking (USNWR) and the Congenital Heart Surgery Database of the Society for Thoracic Surgeons (CHSD-STS), primary based upon early post-operative mortality. This reality places surgeons in a vulnerable position where pressure to achieve a high clinical ranking contrasts with a surgeon definition of "acceptable" surgical risk. Currently, the most frequently used risk stratification tools do not factor in important differences in strategies, such as staged palliation versus complete repair, or bi-ventricular versus uni-ventricular physiology. This favors hospitals pursuing multistage surgical approaches, even if the result is worse long-term morbidity, mortality and increased resource utilization. This economy of ranking-based decision-making causes surgeons either avoid operating altogether or accept less advantageous multi-staged treatment strategies for patients with elevated expected mortality. Such an environment also might present much farther-reaching negative impacts on the growth and development of junior surgeons and trainees, as well as on the pursuit of new surgical innovations to aid future generations of patients.

CONCLUSIONS

Risk aversive surgical behavior is creating an environment not favorable for the children born with truly complex congenital heart defects.

KEYWORDS

Biventricular conversion; congenital heart surgery; multidisciplinary approach; risk-stratification; surgical outcomes.