Normative ranges of biventricular volumes and function in healthy term newborns.

BACKGROUND: Cardiovascular magnetic resonance (CMR) is increasingly used in newborns with congenital heart disease. However, reporting on ventricular volumes and mass is hindered by an absence of normative data in this population. DESIGN/METHODS: Healthy term (37-41 weeks gestation) newborns underwent non-sedated, free-breathing CMR within the first week of life using the 'feed and wrap' technique. End-diastolic volume (EDV), end-systolic volume (ESV) stroke volume (SV) and ejection fraction (EF) were calculated for both left ventricle (LV) and right ventricle (RV). Papillary muscles were separately contoured and included in the myocardial volume. Myocardial mass was calculated by multiplying myocardial volume by 1.05 g/ml. All data were indexed to weight and body surface area (BSA). Inter-observer variability (IOV) was performed on data from 10 randomly chosen infants. RESULTS: Twenty healthy newborns (65% male) with a mean (SD) birth weight of 3.54 (0.46) kg and BSA of 0.23 (0.02) m2 were included. Normative LV parameters were indexed EDV 39.0 (4.1) ml/m2, ESV 14.5 (2.5) ml/m2 and ejection fraction (EF) 63.2 (3.4)%. Normative RV indexed EDV, ESV and EF were 47.4 (4.5) ml/m2, 22.6 (2.9) ml/m2 and 52.5 (3.3)% respectively. Mean LV and RV indexed mass were 26.4 (2.8) g/m2 and 12.5 (2.0) g/m2, respectively. There was no difference in ventricular volumes by gender. IOV was excellent with an intra-class coefficient > 0.95 except for RV mass (0.94). CONCLUSION: This study provides normative data on LV and RV parameters in healthy newborns, providing a novel resource for comparison with newborns with structural and functional heart disease.

Impact of Obesity on Ventriculo-Arterial Interaction in Patients After Coarctation of Aorta repair.

Survival of patients after repair of coarctation of Aorta (CoA) has improved significantly over the decades, but patients have decreased life expectancy as compared to the general population. This has been attributed to increased hypertension, cerebrovascular disease, and coronary artery disease. There has also been an increasing concern of overweight and obesity in patients with adult congenital heart disease. While there have been studies looking at the impact of long-term hypertension on myocardial performance and outcomes in this population, this study aims to assess the impact of obesity in these patients on their myocardial performance. Ventriculo-arterial coupling is used as a measure of myocardial performance which reflects the interaction between cardiac contractility and arterial elastance. Patients after CoA repair are known to have hypertension affecting the arterial elastance. Obesity affects cardiac contractility as well. This study demonstrated that in a group of young patients after CoA repair, body mass index (BMI) has a relationship with left ventricular (LV) contractility and myocardial performance. This relationship was independent of blood pressure. BMI itself was not seen to affect the determinants of diastolic function in this study, suggesting that LV contractility may be affected before one can notice a change in the diastolic function secondary to BMI.

Impact of Socioeconomic Status, Race and Ethnicity, and Geography on Prenatal Detection of Hypoplastic Left Heart Syndrome and Transposition of the Great Arteries.

BACKGROUND: Prenatal detection (PND) has benefits for infants with hypoplastic left heart syndrome (HLHS) and transposition of the great arteries (TGA), but associations between sociodemographic and geographic factors with PND have not been sufficiently explored. This study evaluated whether socioeconomic quartile (SEQ), public insurance, race and ethnicity, rural residence, and distance of residence (distance and driving time from a cardiac surgical center) are associated with the PND or timing of PND, with a secondary aim to analyze differences between the United States and Canada. METHODS: In this retrospective cohort study, fetuses and infants <2 months of age with HLHS or TGA admitted between 2012 and 2016 to participating Fetal Heart Society Research Collaborative institutions in the United States and Canada were included. SEQ, rural residence, and distance of residence were derived using maternal census tract from the maternal address at first visit. Subjects were assigned a SEQ z score using the neighborhood summary score or Canadian Chan index and separated into quartiles. Insurance type and self-reported race and ethnicity were obtained from medical charts. We evaluated associations among SEQ, insurance type, race and ethnicity, rural residence, and distance of residence with PND of HLHS and TGA (aggregate and individually) using bivariate analysis with adjusted associations for confounding variables and cluster analysis for centers. RESULTS: Data on 1862 subjects (HLHS: n=1171, 92% PND; TGA: n=691, 58% PND) were submitted by 21 centers (19 in the United States). In the United States, lower SEQ was associated with lower PND in HLHS and TGA, with the strongest association in the lower SEQ of pregnancies with fetal TGA (quartile 1, 0.78 [95% CI, 0.64-0.85], quartile 2, 0.77 [95% CI, 0.64-0.93], quartile 3, 0.83 [95% CI, 0.69-1.00], quartile 4, reference). Hispanic ethnicity (relative risk, 0.85 [95% CI, 0.72-0.99]) and rural residence (relative risk, 0.78 [95% CI, 0.64-0.95]) were also associated with lower PND in TGA. Lower SEQ was associated with later PND overall; in the United States, rural residence and public insurance were also associated with later PND. CONCLUSIONS: We demonstrate that lower SEQ, Hispanic ethnicity, and rural residence are associated with decreased PND for TGA, with lower SEQ also being associated with decreased PND for HLHS. Future work to increase PND should be considered in these specific populations.

Midterm Outcomes and Cardiac Magnetic Resonance Imaging following Multisystem Inflammatory Syndrome in Children.

At midterm follow-up visits performed at a median of 7 months (IQR 6.0-8.4 months), 16 patients with multisystem inflammatory syndrome in children had resolution of left ventricular dysfunction and most had resolution of coronary aneurysms. On cardiovascular magnetic resonance imaging, no patients had late gadolinium enhancement.

Current State of Fetal Heart Disease Counseling and Training: Room for Improvement? : Endorsed by the Fetal Heart Society.

We sought to describe the fellowship experiences and current practice habits of pediatric cardiologists who counsel patients with fetal heart disease (FHD) and to identify fellowship experiences related to FHD counseling perceived as valuable by respondents as well as opportunities for improvement. A cross-sectional survey of attending pediatric cardiologists who care for patients with FHD was performed. The respondents' demographics, fellowship experiences related to FHD counseling, reflections on fellowship training, and current practice habits were collected. The Fetal Heart Society endorsed this survey. There were 164 survey responses. 56% of respondents did not have 4th-year subspecialty training in fetal cardiology. Observing and performing FHD counseling were the most commonly used methods of training, with the highest perceived effectiveness. The number of counseling sessions observed and performed correlated moderately with confidence in FHD counseling skills at fellowship graduation. Extracardiac pathology and neurodevelopment were the least frequently addressed topics in fellowship training and in current practice. Fewer than 50% of respondents received formal education and feedback in counseling techniques during fellowship training. A significant proportion of practicing pediatric cardiologists provide FHD counseling with only standard categorical training. This highlights the potential importance of expanding FHD counseling education into categorical fellowship curricula. We suggest increasing opportunities for fellows to perform FHD counseling and receive feedback as this is a valued and beneficial experience during training. A formalized curriculum including extracardiac pathology and neurodevelopment and the use of evidence-based workshops in counseling techniques may address identified gaps in fellowship education.

Aneurysms of the fetal arterial duct are usually benign.

INTRODUCTION: Fetal arterial duct aneurysm, saccular, or fusiform enlargement of the arterial duct affect > 8% of pregnancies. It is uncommonly associated with serious sequelae postnatally, including thromboembolic events such as stroke and left pulmonary artery obstruction, rupture with demise, and vocal cord compression. Risk factors include maternal diabetes, late maternal age, maternal blood type A, large size for gestational age, and connective tissue disorders. The clinical importance remains unknown, making it difficult to determine how to monitor this finding postnatally. METHODS: This is a retrospective echocardiogram study assessing the outcomes of fetally diagnosed arterial duct aneurysm. Images and records were reviewed to confirm the diagnosis and assess risk factors and outcomes. Descriptive statistics were performed. RESULTS: Fifty-three affected fetuses were identified. The median gestational age at diagnosis was 34.9 weeks (IQR 32.6, 36.6). The median maternal age was 31 years (IQR 27.3-34.1). Eight (15%) had maternal diabetes. The most common blood type was type O. The median maximal dimension of the aneurysm was 7.6 mm (IQR 6.1, 8.7). The aortic end was the maximal dimension in 67.9%. Median postnatal follow-up period was 76 days (IQR 7.5, 368). No patients sustained postnatal demise related to the duct, rupture of the ductal aneurysm, cerebral infarction, or other sequelae. No newborn had associated connective tissue disorders. No patients underwent ductal intervention. CONCLUSION: In our experience, no adverse outcomes related to the ductal aneurysm were identified. This should be considered when counselling families about the need for postnatal follow-up.

Longitudinal Echocardiographic Assessment of Coronary Arteries and Left Ventricular Function following Multisystem Inflammatory Syndrome in Children.

Myocardial dysfunction and coronary artery dilation have been reported in the acute setting of severe acute respiratory syndrome coronavirus disease-2-related multisystem inflammatory syndrome in children. Through a longitudinal echocardiographic single-center study of 15 children, we report the short-term outcomes of cardiac dysfunction and coronary artery dilation in severe acute respiratory syndrome coronavirus disease-2-related multisystem inflammatory syndrome in children.

Physician variation in ordering of transthoracic echocardiography in outpatient pediatric cardiac clinics.

BACKGROUND: The pediatric Appropriate Use Criteria (AUC) for outpatient transthoracic echocardiography (TTE) aim to reduce practice variation. Little is known on variation in TTE use between physicians. Understanding this variation will help identify areas for improvement in standardization of TTE use. METHODS AND RESULTS: This is a retrospective review of initial outpatient visits at 6 pediatric cardiology centers in the United States prior to AUC release. Variation in TTE use was examined using multilevel generalized mixed effects models. Forward selection identified combinations of variables that explained the most variance in TTE use between physicians. Due to collinearity, physician compensation model and center were analyzed separately. Of 2883 encounters, the most common indication was murmur (36%), followed by chest pain (15.2%). Overall TTE use was 41.9%, and varied widely between centers (22.9%-52.6%), and between physicians within centers. Center alone explained 29% of this physician variance. Adding physician characteristics increased the variance explained to 57%, which only minimally improved by adding patient characteristics. The variance explained was driven by subspecialty. The center-based multivariable model explained more variance over compensation model. CONCLUSIONS: Center was the single largest determinant of physician variance in TTE use, followed by physician subspecialty. Efforts to reduce practice variation, such as the AUC, should be employed across centers and all pediatric cardiac providers. Center appears to have a stronger impact on variance than compensation model, though in this dataset the effect of center and compensation are hard to separate from each other and deserve further evaluation.

Application of the Pediatric Appropriate Use Criteria for Chest Pain.

OBJECTIVES: To characterize the subgroup of outpatient pediatric patients presenting with chest pain and to determine the effectiveness of published pediatric appropriate use criteria (PAUC) to detect pathology. STUDY DESIGN: The Pediatric Appropriate Use of Echocardiography study evaluated the use and yield of transthoracic echocardiography (TTE) before and after PAUC release. Data were reviewed on patients ?18 years of age who underwent TTE for chest pain. Indications were classified as appropriate (A), may be appropriate (M), and rarely appropriate (R) based on PAUC ratings, and findings were normal, incidental, or abnormal. RESULTS: Chest pain was the primary indication in 772 of 4562 outpatient TTE studies (17%) (median age 14 years, IQR 10-16) ordered during the study period: 458 of 772 before (59%) and 314 of 772 after (41 %) the release of PAUC with no change in appropriateness. In A indications (n?=?654), 642 (98%) were normal, 5 (1%) had incidental findings, and 7 (1%) were abnormal. A and M detected 100% of all abnormal findings (A: n?=?7; M: n?=?6; R: n?=?0), with an association between ratings and findings (P?<.001). There was no association between R rating and any pathology. CONCLUSIONS: There was no change in ordering patterns with publication of the PAUC. Despite the high rate of TTEs ordered for indications rated A, most studies were normal. Studies that detected pathology were performed for indications rated A or M, but not R. This study supports PAUC as a useful tool in pediatric chest pain evaluation that may subsequently improve the use of TTE.

Application of pediatric appropriate use criteria for initial outpatient evaluation of syncope.

BACKGROUND: Syncope is a common reason for outpatient transthoracic echocardiography (TTE). We studied the applicability of pediatric appropriate use criteria (AUC) on initial outpatient evaluation of children (≤18 years) with syncope. METHODS: Data were obtained before (Phase I, April-September 2014) and after (Phase II, January-April 2015) the release of the AUC document from six participating pediatric cardiology centers. Site investigators determined the indication for TTE and assigned appropriateness rating based on the AUC document: Appropriate (A), May Be Appropriate (M), Rarely Appropriate (R), or "unclassifiable" (U) if it did not fit any scenario in the AUC document. RESULTS: Of the total 4562 TTEs, 310 (6.8%) were performed for syncope: 174/2655 (6.6%) Phase I and 136/1907 (7.1%) Phase II, P=.44. Overall, 168 (50.5%) were for indications rated A, 63 (18.9%) for M, 79 (23.7%) for R, and 23 (6.9%) for U. Release of AUC did not change the appropriateness of TTEs [A=51.6% vs 49.0%, P=.63, R=20.2% vs 28.3%, P=.09]. Overall syncope-related R indications formed 15.7% of R indications for all the echocardiograms performed in the entire Pediatric Appropriate Use (PAUSE) study (11.9% Phase I and 22.4% Phase II, P=.002). TTEs were normal in majority of the patients except 7 that had incidental findings. CONCLUSIONS: In conclusion, syncope is a common reason for indications rated R and release of the AUC document did not improve appropriate utilization of TTE in syncope. Targeted educational interventions are needed to reduce unnecessary TTEs in children with syncope.

Unplanned Repeat Echocardiography with Sedation in Children: Patient Risk Factors.

Patient selection criteria for echocardiography with sedation in children are not well defined. We attempted to identify predictors of unplanned repeat echocardiography with sedation. This was a single-center, case-control study of echocardiograms performed in children aged 1-36 months. Cases underwent unplanned repeat examinations with sedation, while controls did not. Patient variables and study indications were compared. Logistic regression identified the most significant predictors. Cases (n = 104, median time to repeat echocardiogram 17 days, median age 12.9 months) were older than controls (n = 212, median age 5.0 months, P < 0.001). Significantly more cases than controls had structural cardiac disease (64 vs. 23 %) and anatomic complexity ≥moderate (38 vs. 5 %, P < 0.001 for both). Cases more often had Kawasaki disease (11 vs. 2 %), and controls more often had murmur (56 vs. 11 %, P < 0.001 for both). Logistic regression identified age 6 months to <2 years (OR 3.26, 95 % CI 1.70-6.28, P < 0.001), Kawasaki disease (OR 5.20, 95 % CI 1.46-18.50, P = 0.01), and known pre-echocardiogram anatomic complexity ≥moderate (OR 3.99, 95 % CI 1.64-9.66, P = 0.002) as significant risk factors. An indication for murmur was protective (OR 0.32, 95 % CI 0.13-0.76, P = 0.01). We identified several risk factors for unplanned repeat echocardiography with sedation in children, including age 6 months to <2 years, higher anatomic complexity, and Kawasaki disease. Murmur was a protective factor. These results may help pediatric echocardiography laboratories establish criteria for sedation.

Berry syndrome: the importance of genetic evaluation before surgical intervention.

Berry syndrome is a rare CHD. Approximately 29 cases have been described in the literature. Surgical correction has been successfully performed as well. We report the case of a newborn diagnosed with Berry syndrome who was subsequently diagnosed with trisomy 13. Cytogenetic analysis should be performed before surgical repair for optimal management.

Appropriateness of cardiovascular computed tomography and magnetic resonance imaging in patients with conotruncal defects.

BACKGROUND: To promote the rational use of cardiovascular imaging in patients with congenital heart disease, the American College of Cardiology developed Appropriate Use Criteria (AUC), but its clinical application and pre-release benchmarks have not been evaluated. We aimed to evaluate the appropriateness of indications for cardiovascular magnetic resonance (CMR) and cardiovascular computed tomography (CCT) in patients with conotruncal defects and to identify factors associated with maybe or rarely appropriate (M/R) indications. METHODS: Twelve centers each contributed a median of 147 studies performed prior to AUC publication (01/2020) on patients with conotruncal defects. To incorporate patient characteristics and center-level effects, a hierarchical generalized linear mixed model was used. RESULTS: Of the 1753 studies (80% CMR, and 20% CCT), 16% were rated M/R. Center M/R ranged from 4 to 39%. Infants accounted for 8.4% of studies. In multivariable analyses, patient- and study-level factors associated with M/R rating included: age <1 year (OR 1.90 [1.15-3.13]), truncus arteriosus (vs. tetralogy of Fallot, OR 2.55 [1.5-4.35]), and CCT (vs. CMR, OR 2.67 [1.87-3.83]). None of the provider- or center-level factors reached statistical significance in the multivariable model. CONCLUSIONS: Most CMRs and CCTs ordered for the follow-up care of patients with conotruncal defects were rated appropriate. However, there was significant center-level variation in appropriateness ratings. Younger age, CCT, and truncus arteriosus were independently associated with higher odds of M/R rating. These findings could inform future quality improvement initiatives and further exploration of factors resulting in center-level variation.

Impact of maternal obesity on neonatal heart rate and cardiac size.

BACKGROUND: Maternal obesity may increase offspring risk of cardiovascular disease. We assessed the impact of maternal obesity on cardiac structure and function in newborns as a marker of fetal cardiac growth. METHODS: Neonates born to mothers of healthy weight (body mass index (BMI) 20-25 kg/m2, n=56) and to mothers who were obese (BMI ≥30 kg/m2, n=31) underwent 25-minute continuous ECG recording and non-sedated, free-breathing cardiac MRI within 72 hours of birth. RESULTS: Mean (SD) heart rate during sleep was higher in infants born to mothers who were versus were not obese (123 (12.6) vs 114 (9.8) beats/min, p=0.002). Heart rate variability during sleep was lower in infants born to mothers who were versus were not obese (SD of normal-to-normal R-R interval 34.6 (16.8) vs 43.9 (16.5) ms, p=0.05). Similar heart rate changes were seen during wakefulness. Left ventricular end-diastolic volume (2.35 (0.14) vs 2.54 (0.29) mL/kg, p=0.03) and stroke volume (1.50 (0.09) vs 1.60 (0.14), p=0.04) were decreased in infants born to mothers who were versus were not obese. There were no differences in left ventricular end-systolic volume, ejection fraction, output or myocardial mass between the groups. CONCLUSION: Maternal obesity was associated with increased heart rate, decreased heart rate variability and decreased left ventricular volumes in newborns. If persistent, these changes may provide a causal mechanism for the increased cardiovascular risk in adult offspring of mothers with obesity. In turn, modifying antenatal and perinatal maternal health may have the potential to optimise long-term cardiovascular health in offspring.

Diagnostic Accuracy of Fetal Echocardiography in Congenital Heart Disease.

BACKGROUND: The accuracy of fetal echocardiography (FE) is not well defined, and reporting of diagnostic discrepancies (DDs) is not standardized. The authors applied a categorization scheme developed by the American College of Cardiology Quality Metric Working Group and applied it to FE. METHODS: A retrospective single-center study was conducted of prenatally diagnosed major structural congenital heart disease, defined as expected need for intervention within the first year of life. DDs between pre- and postnatal findings were identified and categorized. Minor DDs had no clinical impact, moderate DDs had impact without harm, and severe DDs resulted in adverse events. Multivariate regression analysis was used to determine factors associated with discrepancy. RESULTS: From December 2008 to September 2017, 17,096 fetal echocardiograms were obtained, among which 222 fetuses with a median gestational age at first FE of 24 weeks were included. There were 30 DDs (13.5%), of which the majority were false negatives (56.7%). Most were minor or moderate in severity, with one severe DD. The majority were possibly preventable (90%), with the most common contributing factor being technical limitations (43.3%). The most common anatomic segment involved was the ventricular septum (23%), primarily missed septal defects. Comparing cases with DDs versus those without, those with DDs were more likely to have high anatomic complexity (16.7% vs 3.6%, P = .01), maternal comorbidities (40.0% vs 22.1%, P = .03), and a younger maternal age (median, 27 vs 30 years, P = .02). They were also more likely to have later gestation at initial FE (median, 29.5 vs 24 weeks, P = .003), to have fewer total fetal echocardiograms (median, 2 vs 3, P = .002), and to have a fellow as the initial sonographer (36.7% vs 16.7%, P = .03). There were no significant differences in maternal race/ethnicity, fetal comorbidities, and interpreting physician experience between cases with DDs and those without. On multivariate analysis, variables associated with DD included high anatomic complexity, maternal comorbidities, and fellow as initial imager. A greater number of fetal echocardiograms was associated with reduced DD. CONCLUSIONS: FE had a DD rate of 13.5%, mostly minor and moderate in severity. Factors associated with DD included high anatomic complexity, maternal comorbidities, fellow as the initial sonographer, and fewer fetal echocardiograms. Strategies to reduce DD could include a regular secondary review and repeat FE, particularly when anatomic complexity is high.

Epicardial Echocardiography in Pediatric and Congenital Heart Surgery.

Epicardial echocardiography (e-echo) is a useful approach to intraoperative imaging for the smallest patients and in those with contraindications to transesophageal echocardiography (TEE). The e-echo has additional advantages that include improved visualization of anterior and vascular structures and three-dimensional capabilities. In this review, we describe the advantages and disadvantages of e-echo versus TEE for pediatric and congenital heart surgery with the goal of enhancing the utility and feasibility of the former among congenital heart surgeons. We also review the technique for performance of an e-echo and provide demonstrations of the images obtained for select lesions.

Clinical yield of fetal echocardiography for suboptimal cardiac visualization on obstetric ultrasound.

OBJECTIVE: Suboptimal cardiac imaging on obstetric ultrasound is a frequent referral indication for fetal echocardiography, even in the absence of typical risk factors for fetal cardiac disease. The clinical profile of patients and findings of examinations performed for such an indication are not well defined. Given the increased cost, time and resource utilization of fetal echocardiography, we sought to determine the clinical findings of such referrals. STUDY DESIGN: We performed a single-center review of such referrals from January 2010 to June 2016. Patients with commonly accepted indications for fetal echocardiography were excluded. Demographic variables and echocardiogram findings were collected. Findings were classified as (1) "normal," (2) "probably normal," if minor pathology could not confidently be excluded, or if minor findings were noted that were expected to resolve, or (3) "abnormal." Rates of pathology were determined with comparison of nonobese and obese populations. RESULTS: A total of 583 gestations in 562 women were included (median gestational age 23.3 weeks, range 19.0-38.4). The median body mass index (BMI) was 34.6 kg/m2 (range 17.2-66.3 kg/m2 ). The majority of women were obese (BMI ≥ 30 kg/m2 in 74.6%). Overall, 574 of 583 examinations (98.5%) were normal or "probably normal." Pathology was noted in 9 fetuses (1.5%), 3 of whom required intervention (0.5%). No ductal dependent lesions were diagnosed. There was no significant difference in pathology rates between nonobese and obese mothers. CONCLUSIONS: We found a low fetal cardiac anomaly rate in studies performed for suboptimal views on obstetric ultrasound. The majority of women referred for this indication were obese. The practice of routine referral for this indication deserves further evaluation.

Predictors of inadequate initial echocardiography in suspected Kawasaki disease: Criteria for sedation.

OBJECTIVE: Kawasaki disease is the primary cause of acquired pediatric heart disease in developed nations. Timely diagnosis of Kawasaki disease incorporates transthoracic echocardiography for visualization of the coronary arteries. Sedation improves this visualization, but not without risks and resource utilization. To identify potential sedation criteria for suspected Kawasaki disease, we analyzed factors associated with diagnostically inadequate initial transthoracic echocardiography performed without sedation. DESIGN: This retrospective review of patients < 18 years old undergoing initial transthoracic echocardiography for the inpatient evaluation of suspected Kawasaki disease from 2009 to 2015 occurred at a medium-sized urban children's hospital. The primary outcome was diagnostically inadequate transthoracic echocardiography without sedation due to poor visualization of the coronary arteries, determined by review of clinical records. The associations of the primary outcome with demographics, Kawasaki disease type, laboratory data, fever, and antipyretic or intravenous immunoglobulin treatment prior to transthoracic echocardiography were analyzed. RESULTS: In total, 112 patients (44% female, median age 2.1 years, median BSA 0.54 m2 ) underwent initial transthoracic echocardiography for suspected Kawasaki disease, and 99 were not sedated. Transthoracic echocardiography was diagnostically inadequate in 19 out of these 99 patients (19.2%) and was associated with age ≤ 2.0 years, weight ≤ 10.0 kg, and antipyretic use ≤ 6 hours before transthoracic echocardiography (all P < .05). These variables did not reach statistical significance on multivariable analysis. CONCLUSIONS: Patients ≤ 2.0 years or ≤ 10.0 kg or those recently receiving antipyretics, potentially a surrogate for irritability, were associated with diagnostically inadequate transthoracic echocardiography during the inpatient workup of Kawasaki disease. These factors should be considered when deciding which patients to sedate for initial Kawasaki disease transthoracic echocardiography.