Environmental Exposures and Pediatric Cardiology: A Scientific Statement From the American Heart Association.

Environmental toxicants and pollutants are causes of adverse health consequences, including well-established associations between environmental exposures and cardiovascular diseases. Environmental degradation is widely prevalent and has a long latency period between exposure and health outcome, potentially placing a large number of individuals at risk of these health consequences. Emerging evidence suggests that environmental exposures in early life may be key risk factors for cardiovascular conditions across the life span. Children are a particularly sensitive population for the detrimental effects of environmental toxicants and pollutants given the long-term cumulative effects of early-life exposures on health outcomes, including congenital heart disease, acquired cardiac diseases, and accumulation of cardiovascular disease risk factors. This scientific statement highlights representative examples for each of these cardiovascular disease subtypes and their determinants, focusing specifically on the associations between climate change and congenital heart disease, airborne particulate matter and Kawasaki disease, blood lead levels and blood pressure, and endocrine-disrupting chemicals with cardiometabolic risk factors. Because children are particularly dependent on their caregivers to address their health concerns, this scientific statement highlights the need for clinicians, research scientists, and policymakers to focus more on the linkages of environmental exposures with cardiovascular conditions in children and adolescents.

Nondental Invasive Procedures and Risk of Infective Endocarditis: Time for a Revisit: A Science Advisory From the American Heart Association.

There have been no published prospective randomized clinical trials that have: (1) established an association between invasive dental and nondental invasive procedures and risk of infective endocarditis; or (2) defined the efficacy and safety of antibiotic prophylaxis administered in the setting of invasive procedures in the prevention of infective endocarditis in high-risk patients. Moreover, previous observational studies that examined the association of nondental invasive procedures with the risk of infective endocarditis have been limited by inadequate sample size. They have typically focused on a few potential at-risk surgical and nonsurgical invasive procedures. However, recent investigations from Sweden and England that used nationwide databases and demonstrated an association between nondental invasive procedures, and the subsequent development of infective endocarditis (in particular, in high-risk patients with infective endocarditis) prompted the development of the current science advisory.

Fontan Fenestration Reduction with an Occlutech Atrial Flow Regulator: Unique Views from Three-Dimensional Intracardiac Echocardiography.

Three-dimensional intracardiac echocardiography (3D ICE) has gained popularity in interventional cardiology given its improved spatial and temporal imaging in assessing intracardiac anatomy pre- and post-intervention. We describe the use of 3D ICE in the reduction of a Fontan fenestration with an Occlutech atrial flow regulator (AFR) device.

SARS-CoV-2 Infection and Associated Cardiovascular Manifestations and Complications in Children and Young Adults: A Scientific Statement From the American Heart Association.

Coronavirus disease 2019 (COVID-19) resulted in a global pandemic and has overwhelmed health care systems worldwide. In this scientific statement, we describe the epidemiology, pathophysiology, clinical presentations, treatment, and outcomes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and multisystem inflammatory syndrome in children and young adults with a focus on cardiovascular manifestations and complications. We review current knowledge about the health consequences of this illness in children and young adults with congenital and acquired heart disease, the public health burden and health disparities of this infection in these populations, and vaccine-associated myocarditis.

Three-Dimensional, Right Ventricular Surface Strain Computation From Three-Dimensional Echocardiographic Images From Patients With Pediatric Pulmonary Hypertension.

Right Ventricular (RV) dysfunction is routinely assessed with echocardiographic-derived global longitudinal strain (GLS). GLS is measured from a two-dimensional echo image and is increasingly accepted as a means for assessing RV function. However, any two-dimensional (2D) analysis cannot visualize the asymmetrical deformation of the RV nor visualize strain over the entire RV surface. We believe three-dimensional surface (3DS) strain, obtained from 3D echo will better evaluate myocardial mechanics. Components of 3DS strain (longitudinal, LS; circumferential, CS; longitudinal-circumferential shear, ɣCL; principal strains PSMax and PSMin; max shear, ɣMax; and principal angle θMax) were computed from RV surface meshes obtained with 3D echo from 50 children with associated pulmonary arterial hypertension (PAH), 43 children with idiopathic PAH, and 50 healthy children by computing strains from a discretized displacement field. All 3DS freewall (FW) normal strain (LS, CS, PSMax, and PSMin) showed significant decline at end-systole in PH groups (p < 0.0001 for all), as did FW-ɣMax (p = 0.0012). FW-θMax also changed in disease (p < 0.0001). Limits of agreement analysis suggest that 3DS LS, PSMax, and PSMin are related to GLS. 3DS strains showed significant heterogeneity over the 3D surface of the RV. Components of 3DS strain agree with existing clinical strain measures, well classify normal -versus- PAH subjects, and suggest that strains change direction on the myocardial surface due to disease. This last finding is similar to that of myocardial fiber realignment in disease, but further work is needed to establish true associations.

Imaging Evaluation of Kawasaki Disease.

PURPOSE OF REVIEW: This review provides the summary of the appropriate use of these modalities when caring for patients with Kawasaki disease at diagnosis and for long-term management. RECENT FINDINGS: Kawasaki disease is an inflammatory syndrome of unknown etiology that can result in coronary artery dilations or aneurysms if left untreated in 25% of the patients and 3-5% in treated patients. In addition to coronary artery aneurysms, patients can have ventricular dysfunction, valvular regurgitation, aortic root dilation, and pericardial effusion due to inflammation of the myocardium. Noninvasive imaging modalities are important to these assessments. Echocardiography is the first-line noninvasive evaluation of coronaries and function. Cardiac magnetic resonance imaging is useful for functional assessment in long-term follow-up. Distal coronaries, thromboses, and stenoses are best evaluated by cardiac computed tomography. Future research should demonstrate the effectiveness of advanced functional imaging in patients with Kawasaki disease and decreased radiation from cardiac computed tomography.

Transesophageal three-dimensional echocardiographic guidance for pacemaker lead extraction.

BACKGROUND: The ability of transesophageal three-dimensional echocardiography (3DE) to aid in pacemaker lead extraction has not yet been evaluated. 3DE provides real-time evaluation of intracardiac anatomy and the location of pacemaker leads in greater detail than either fluoroscopy or -two-dimensional echocardiography (2DE), aiding in the extraction of such leads, which can be potentially dangerous. We sought to investigate the feasibility and utility of 3DE to visualize intracardiac anatomy and pacemaker leads, and to assist in lead extraction procedures. METHODS: We utilized 3DE in nine encounters for eight different patients, to visualize intracardiac anatomy and leads before, during, and after extraction to evaluate the feasibility and utility to aid in the procedure and evaluate for potential sequelae. RESULTS: 3DE was able to identify pertinent intracardiac anatomy and leads in all cases. 3DE detected procedural complications or altered management in five of nine encounters (five of eight patients); this included detection of an avulsed papillary muscle, tricuspid valve leaflet damage, and cast/thrombus after lead removal, as well as adjustment of excess lead slack to avoid future valve damage, or risk stratification of lead removal. CONCLUSION: 3DE is feasible and adds utility to lead extraction cases by visualizing intracardiac anatomy and leads beyond fluoroscopy or 2DE, providing real-time information during extraction, and identifying potential complications.

A multicenter study of three-dimensional echocardiographic evaluation of normal pediatric left ventricular volumes and function.

BACKGROUND: Three-dimensional echocardiography (3DE) evaluation of left ventricular (LV) volume and function in pediatrics compares favorably with cardiac magnetic resonance imaging. The aim of this study was to establish from a multicenter, normal pediatric z-score values of 3DE left ventricular volumes and function. METHODS: Six hundred and ninety-eight healthy children (ages 0-18 years) were recruited from five centers. LV 3DE was acquired from the 4-chamber view. A vendor-independent software analyzed end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), and ejection fraction (EF) using semi-automated quantification. Body surface area (BSA)-based z-scores were generated. Intraobserver and interobserver variability were calculated using intraclass correlation (ICC) and repeatability coefficient (RC). RESULTS: Z-scores were generated for ESV, EDV, and SV. The ICC for intraobserver variability for EDV, ESV, and SV was 0.99, 0.99, and 0.99, respectively. The ICC for interobserver variability for EDV, ESV, and SV was 0.98, 0.94, and 0.98, respectively. The RC for intraobserver and interobserver variability for LV EF was 4.39% (95% CI: 3.01, 5.59) and interobserver was 7.08% (95%CI: 5.51, 8.42). CONCLUSIONS: We report pediatric z-scores for normal LV volumes using the semi-automated method from five centers, enhancing its generalizability. 3DE evaluation of LV volumes and EF in pediatric patients is highly reproducible.

Circulating microRNAs differentiate Kawasaki Disease from infectious febrile illnesses in childhood.

BACKGROUND: Kawasaki Disease (KD) is an acute vasculitis of unknown etiology in children that can lead to coronary artery lesions (CAL) in 25% of untreated patients. There is currently no diagnostic test for KD, and the clinical presentation is often difficult to differentiate from other febrile childhood illnesses. Circulating microRNAs (miRNAs) are small noncoding RNA molecules that control gene expression by inducing transcript degradation or by blocking translation. We hypothesize that the expression of circulating miRNAs will differentiate KD from non-KD febrile illnesses in children. METHODS: Circulating miRNA profiles from 84 KD patients and 29 non-KD febrile controls (7 viral and 22 bacterial infections) were evaluated. 3 ul of serum from each subject was submitted to 3 freeze/heat cycles to ensure miRNA release from microvesicles or interaction with serum proteins. miRNAs were reverse transcribed using a pool of primers specific for each miRNA. Real-time PCR reactions were performed in a 384 well plate containing sequence-specific primers and TaqMan probes in the ABI7900. '. RESULTS: KD patients (3.6 ± 2.2 yrs., 58% male) were found to have a unique circulating miRNA profile, including upregulation of miRNA-210-3p, -184, and -19a-3p (p < .0001), compared to non-KD febrile controls (8.5 ± 6.1 yrs., 72% male). CONCLUSIONS: Circulating miRNAs can differentiate KD from infectious febrile childhood diseases, supporting their potential as a diagnostic biomarker for KD.

Applications of three-dimensional transesophageal echocardiography in congenital heart disease.

Three-dimensional echocardiography allows for presurgical planning for congenital heart disease, reduces radiation using fusion imaging in catheter interventions, and provides guidance during catheter interventions and lead placements or extractions. The purpose of this review is to detail applications of three-dimensional transesophageal echocardiography in presurgical planning of congenital heart disease, guidance of catheter interventions such as fusion imaging, and guidance in electrophysiology lead extractions or placements.

Echocardiography-fluoroscopy fusion imaging: The essential features used in congenital and structural heart disease interventional guidance.

Increased catheter-based interventions in congenital and structural heart disease require imaging modalities to be oriented in the same visual perspective. The use of echocardiography-fluoroscopy fusion (EFF) imaging has been developed for better characterization of complex anatomy and to facilitate key steps in interventional procedures. This review will detail the technology behind EFF, the differences between the two ultrasound fusion systems, and essential features of EFF imaging in congenital and structural heart disease interventions.

Aortic Coarctation: A Comprehensive Analysis of Shape, Size, and Contractility of the Fetal Heart.

BACKGROUND: An integrated assessment of the size and shape of the 4-chamber view (4-CV) and right and left ventricles (RV and LV) as well as the function of the RV and LV in fetuses with coarctation of the aorta (CoA) has not yet been conducted. OBJECTIVES: We evaluated the size and shape of the 4-CV, RV, and LV, and function of the RV and LV, to identify a profile for fetuses with CoA when compared to a control population. METHODS: 50 CoA fetuses were compared to 200 controls. This was a retrospective case series comparing the 4-CV of CoA fetuses and controls. The 4-CV end-diastolic area, length, width, and sphericity index were measured to determine the configuration of the 4-CV. Speckle-tracking analysis was used to compute the RV and LV end-diastolic area, length, 24-segment sphericity index, 24-segment transverse width, and the following functional parameters: (1) fractional area change; (2) global, lateral, and septal strain; (3) basal-apical, lateral, and septal annular displacement and fractional shortening; and (4) 24-segment transverse width fractional shortening. Using 5 and 95% reference intervals, the CoA fetal measurements were classified; from these, the odds ratio was computed between the fetuses with CoA and the controls. p < 0.05 was considered significant. RESULTS: In fetuses with CoA, the 4-CV was spherical in shape, increased in area and width, and decreased in length. Abnormal CoA sphericity indices reflected a flatter LV and a more spherical RV. The LV area, length, and width, and RV length were decreased. The transverse width of the RV was increased. RV and LV global, longitudinal, and transverse contractility were depressed. CONCLUSIONS: The results demonstrate previously unappreciated differences in the shape, size, and function of the heart in fetuses with CoA. These differences may assist examiners in identifying fetuses with CoA.

Phase I/IIa Trial of Atorvastatin in Patients with Acute Kawasaki Disease with Coronary Artery Aneurysm.

OBJECTIVES: To determine the safety, tolerability, pharmacokinetics, and immunomodulatory effects of a 6-week course of atorvastatin in patients with acute Kawasaki disease with coronary artery (CA) aneurysm (CAA). STUDY DESIGN: This was a Phase I/IIa 2-center dose-escalation study of atorvastatin (0.125-0.75 mg/kg/day) in 34 patients with Kawasaki disease (aged 2-17 years) with echocardiographic evidence of CAA. We measured levels of the brain metabolite 24(S)-hydroxycholesterol (24-OHC), serum lipids, acute-phase reactants, liver enzymes, and creatine phosphokinase; peripheral blood mononuclear cell populations; and CA internal diameter normalized for body surface area before atorvastatin treatment and at 2 and 6 weeks after initiation of atorvastatin treatment. RESULTS: A 6-week course of up to 0.75 mg/kg/day of atorvastatin was well tolerated by the 34 subjects (median age, 5.3 years; IQR, 2.6-6.4 years), with no serious adverse events attributable to the study drug. The areas under the curve for atorvastatin and its metabolite were larger in the study subjects compared with those reported in adults, suggesting a slower rate of metabolism in children. The 24-OHC levels were similar between the atorvastatin-treated subjects and matched controls. CONCLUSIONS: Atorvastatin was safe and well tolerated in our cohort of children with acute Kawasaki disease and CAA. A Phase III efficacy trial is warranted in this patient population, which may benefit from the known anti-inflammatory and immunomodulatory effects of this drug.

Right atrial function in pediatric heart transplant patients by echocardiographic strain measurements.

BACKGROUND: CAV is a major cause of mortality in PHTx patients. Research on echocardiographic indices to detect CAV focuses primarily on ventricular function and less is known about RAF. Thus, we primarily sought to evaluate RAF in PHTx patients with CAV. For secondary analysis, we compared RAF between PHTx patients and control patients and evaluated RAF with respect to rejection and surgical type. METHODS: We retrospectively evaluated echocardiography derived RA strain indices in recipients <18 years old and >1 year from time of transplant. The RA strain phases included, reservoir (εs), conduit (εe), pump (εa), and respective strain rate indices (SRs, SRe, SRa). RESULTS: There were 36 PHTx patients and 14 age-, sex-matched control patients. There was a significant reduction in εs, εe, SRs, and SRe (P < 0.001) in the PHTx patients when compared to controls. There was no difference between the CAV (+) and CAV (-) patients with respect to RAF indices. Furthermore, εs, εe, and SRe (P < 0.05) were lower in patients with acute rejection (n = 7) compared to those without (n = 26). Patients with a bi-atrial anastomosis (n = 14) had decreased εs, εa, SRs, SRa (P < 0.05), compared to bi-caval anastomosis (n = 24). CONCLUSION: PHTx patients have decreased RAF compared to healthy children. RAF does not differentiate PHTx patients based on the presence of CAV. RAF is also decreased in PHTx patients with rejection and in those transplanted with a bi-atrial anastomosis.

Vascular anatomical considerations and clinical decision making during insertion of the Avalon® Elite Dual Lumen single-site veno-venous ECMO cannula in children weighing less than 20 kg.

The correct selection and placement of a single-site Avalon® Elite Dual Lumen Cannula for veno-venous extracorporeal membrane oxygenation (ECMO) in children weighing less than 20 kg is dependent on both the mechanical characteristics of the catheter, including length and diameter, as well as the unique vascular anatomic considerations of the patient. This manuscript describes the development of a clinical strategy, over a four-year period from 2012-2016, for cannula selection to reduce the risk of migration and malposition in 20 critically ill children weighing less than 20 kg who presented for veno-venous ECMO.

Myocardial Perfusion Reserve Index in Children With Kawasaki Disease.

BACKGROUND: Coronary artery lesions in patients with Kawasaki disease (KD) can impair myocardial perfusion, yet evaluation of perfusion defects by cardiac magnetic resonance (MR) in children is often qualitative. PURPOSE: In this study we aimed to use a quantitative method of myocardial perfusion using stress cardiac MR-derived myocardial perfusion reserve index (MPRI) in children with KD and compare MPRI with ventricular mechanical performance evaluated by cardiac MR strain analysis. STUDY TYPE: This study was a retrospective review. SUBJECTS: Twenty-one children with a diagnosis of KD who underwent stress perfusion cardiac MR were compared with nine controls. FIELD STRENGTH/SEQUENCE: First-pass perfusion imaging using a T1 -weighted gradient echo sequence was performed at rest and stress after administration of adenosine with 1.5T or 3T magnets. ASSESSMENT: The MPRI was calculated as the ratio of maximum slope of myocardial enhancement during stress compared to rest and was evaluated with the American Heart Association 17 segment model. STATISTICAL TESTS: Demographic and clinical characteristics among KD patients and controls were compared using Student's t-test for normally distributed continuous variables, Wilcoxon-rank sum test for nonnormally distributed variables, and χ2 for categorical variables. RESULTS: There was a significant decrease in MPRI in Segment 7 (1.53 vs. 2.23, P = 0.0058) in KD patients compared with controls. The reduction in MPRI in Segment 12 approached statistical significance (1.58 vs. 2.31, P = 0.0636). Three patients who underwent serial studies had decreased MPRI longitudinally. No differences were seen in circumferential or radial strain. DATA CONCLUSION: MPRI shows impaired myocardial perfusion in patients with KD. MPRI can change over time, suggestive of progressive coronary artery changes, which may precede fibrosis and mechanical decline. MPRI can assess segmental and global perfusion defects in patients with KD and should be a part of routine cardiac MR evaluation in KD. LEVEL OF EVIDENCE: 3 Technical Efficacy Stage 3 J. Magn. Reson. Imaging 2017.

Children with kawasaki disease present elevated stiffness of great arteries: Phase-contrast MRI study.

BACKGROUND: Patients with diagnosed Kawasaki disease (KD) are known to develop extracardiac vascular lesions and are prone to accelerated stiffening of medium-size arteries. PURPOSE: To noninvasively evaluate great vessel (central aorta and main pulmonary artery (MPA)) stiffness using phase-contrast MRI (PC-MRI). STUDY TYPE: Retrospective review. SUBJECTS: Thirty-three patients with previously diagnosed KD and 15 control subjects underwent PC-MRI evaluation. FIELD STRENGTH/SEQUENCE: A free-breathing PC-MRI sequence was applied with Cartesian encoding and retrospective sorting using a 1.5 or 3.0T system. ASSESSMENT: We evaluated regionally specific vessel stiffness using pulse-wave velocity (PWV) and relative area change (RAC) at the ascending aorta, descending aorta, and MPA. STATISTICAL TESTS: Hemodynamics among patients with KD and controls were compared using Student's t-test, Wilcoxon Rank-sum, and χ2 . Additional group-specific comparisons were performed using Kruskal-Wallis or one-way analysis of variance (ANOVA). RESULTS: Patients with KD showed elevated PWV in both ascending (5.0 ± 1.2 vs. 2.4 ± 0.5, P < 0.001) and descending aorta (4.4 ± 2.1 vs. 2.8 ± 0.8, P < 0.001). RAC was correspondingly reduced in both segments (both P < 0.01). PWV measured in MPA was increased in KD patients (2.2 ± 0.5 vs. 1.5 ± 0.6, P = 0.045) while the RAC was reduced (34 ± 6 vs. 47 ± 3, P = 0.045). There were no associations between considered vessel stiffness indices and respective ventricular size and function, functional indices, and no correlations were observed with KD severity markers. DATA CONCLUSION: Patients with KD have elevated great vessel stiffness measured at the chronic stage of the disease. Accelerated stiffness process does not appear to affect biventricular function in youth Level of Evidence: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:1228-1236.

Data-Driven Quality Improvement Project to Increase the Value of the Congenital Echocardiographic Report.

Echocardiography is the primary diagnostic modality for congenital heart disease patients. The written report is used to communicate with the care team and organization is often divided into the body with detailed findings and the conclusions with important findings summarized. Strategies to increase workflow efficiency include batch writing of reports after performance of multiple echocardiograms and the use of report templates which may contribute to discrepancies within report leading to potential downstream medical errors. The aim of this project was to measure the rate of inconsistencies in the echocardiogram reports and through an iterative series of process improvement decrease this rate while maintaining sonographer efficiency and diagnostic accuracy. The discrepancy rate, diagnostic error rate, and sonographer productivity were collected one-year prior and during the iterative quality improvement process. The primary outcome and discrepancies in reports were determined by two reviewers: an experienced pediatric echocardiographic cardiologist and a senior sonographer. Minor discrepancies were defined as contradictions between the body and the conclusion of the report that were unlikely to affect patient care. Major discrepancies were defined as discrepancies between the body and the conclusion that had significant potential to affect patient care. Sonographer productivity was measured as studies per sonographer per month. Our primary intervention was to initiate a quarterly QI meeting and to decrease the batch writing of preliminary echocardiogram reports. No major discrepancies were identified pre- or post-intervention. The minor discrepancies decreased from 40.7 to 6%. Sonographer productivity was not significantly changed with a slight increase from 100 studies/sonographer/month during the baseline to 101 studies/sonographer/month during the intervention. There was no change in major or minor diagnostic error rate. Our quality improvement intervention increased the value of our reports by significantly decreasing minor discrepancies without negatively impacting sonographer productivity or diagnostic accuracy.

Right Ventricular Tissue Doppler Myocardial Performance Index in Children with Pulmonary Hypertension: Relation to Invasive Hemodynamics.

Right ventricular (RV) failure is a significant cause of morbidity and mortality in patients with pulmonary hypertension (PH). Myocardial performance index measured by tissue Doppler imaging (TDI-MPI) has been useful in assessing RV dysfunction in adults with PH. However, TDI-MPI as a marker for RV dysfunction or disease severity has not been evaluated in pediatric PH. The aim of this study was to investigate TDI-MPI and correlate with invasive hemodynamics in pediatric PH patients. Eighty pediatric PH patients undergoing cardiac catheterization and simultaneous transthoracic echocardiography were analyzed. RV TDI-MPI was averaged over three cardiac cycles and measured under each condition of vasodilatory testing during the catheterization. TDI-MPI was compared between PH patients and age-matched controls and correlated to invasive hemodynamics. RV TDI-MPI was increased in PH patients compared to controls (0.49 vs. 0.35, p < 0.0001). Significant associations (beta ± SE) are seen between RV TDI-MPI and baseline mean pulmonary arterial pressures (0.0002 ± 0.001, p < 0.05), indexed pulmonary vascular resistance (0.007 ± 0.002, p < 0.002), and pulmonary-to-systemic arterial pressure ratio (0.146 ± 0.063, p < 0.05). No statistically significant associations were seen with vasodilatory testing. RV TDI-MPI is elevated in children with PH, suggestive of RV dysfunction. RV TDI-MPI shows correlation with severity of PH at baseline but lacks sensitivity to evaluate the RV response to acute changes in afterload in children with PH. Therefore, while RV TDI-MPI can help identify RV dysfunction in children with PH, its utility as a non-invasive surrogate marker for acute changes in hemodynamics is limited.

Three-dimensional echocardiographic evaluation of Ebstein's anomaly of the tricuspid valve in a patient with hypoplastic left heart syndrome.

We report three-dimensional imaging of a rare finding of Ebstein's anomaly of the tricuspid valve in a patient with hypoplastic left heart syndrome, which has been previously reported only by two-dimensional echocardiography. A fetal echocardiogram was performed at 19 weeks that showed a moderately hypoplastic left ventricle, severely hypoplastic mitral valve, a severely hypoplastic aortic valve, and a dysplastic tricuspid valve. Post Caesarean delivery at 40 weeks of gestation, a transthoracic echocardiogram confirmed the findings seen on the fetal echocardiogram. A three-dimensional echocardiogram was then performed, which demonstrated an Ebstein tricuspid valve with apical displacement of the septal leaflet, chordal attachments of the valve to the right ventricular outflow tract, and moderate tricuspid regurgitation. The patient underwent a successful heart transplantation.