The Utility of Outpatient Echocardiography for Evaluation of Asymptomatic Murmurs in Children

Automated analysis of heart sound signals in screening for structural heart disease in children

Our aim was to investigate the ability of an artificial intelligence (AI)-based algorithm to differentiate innocent murmurs from pathologic ones. An AI-based algorithm was developed using heart sound recordings collected from 1413 patients at the five university hospitals in Finland. The corresponding heart condition was verified using echocardiography. In the second phase of the study, patients referred to Helsinki New Children's Hospital due to a heart murmur were prospectively assessed with the algorithm, and then the results were compared with echocardiography findings. Ninety-eight children were included in this prospective study. The algorithm classified 72 (73%) of the heart sounds as normal and 26 (27%) as abnormal. Echocardiography was normal in 63 (64%) children and abnormal in 35 (36%). The algorithm recognized abnormal heart sounds in 24 of 35 children with abnormal echocardiography and normal heart sounds with normal echocardiography in 61 of 63 children. When the murmur was audible, the sensitivity and specificity of the algorithm were 83% (24/29) (confidence interval (CI) 64-94%) and 97% (59/61) (CI 89-100%), respectively.

CONCLUSION

The algorithm was able to distinguish murmurs associated with structural cardiac anomalies from innocent murmurs with good sensitivity and specificity. The algorithm was unable to identify heart defects that did not cause a murmur. Further research is needed on the use of the algorithm in screening for heart murmurs in primary health care.

WHAT IS KNOWN

• Innocent murmurs are common in children, while the incidence of moderate or severe congenital heart defects is low. Auscultation plays a significant role in assessing the need for further examinations of the murmur. The ability to differentiate innocent murmurs from those related to congenital heart defects requires clinical experience on the part of general practitioners. No AI-based auscultation algorithms have been systematically implemented in primary health care.

WHAT IS NEW

• We developed an AI-based algorithm using a large dataset of sound samples validated by echocardiography. The algorithm performed well in recognizing pathological and innocent murmurs in children from different age groups.

Major congenital heart defects are rarely diagnosed after newborns' hospital discharge with modern screening

AIM

Our aim was to assess undiagnosed congenital heart defects (CHD) after newborns' hospital discharge in patients with a murmur or CHD suspicion, to find out the signs that predict CHDs and to estimate the costs of the examinations.

METHODS

We reviewed retrospective medical records of patients (n = 490) referred for the evaluation of CHD suspicion during 2017-2018.

RESULTS

The median age of the patients was 2.5 (IQR 0.5-7.4) years. Sixty-three (13%) patients had an abnormal echocardiography. Neither ductal-dependent nor cyanotic CHDs were found. Cardiac interventions were performed for 14 out of 63 (22%) patients. Clinical signs indicating CHDs were murmur grade ≥3 (10/11 [91%] vs. 53/479 [11%], p < 0.001) and harsh murmur (15/44 [34%] vs. 48/446 [11%], p < 0.001). Abnormal electrocardiography did not indicate CHD (8/40 [20%] vs. 55/447 [12%], p = 0.165). The total cost of the examinations was 259 700€. The share of the cost of studies assessed as benign was 59%.

CONCLUSION

Only a few CHDs were found after newborn hospital discharge among patients who received foetal and newborn screening and were examined due to CHD suspicion. The high number of benign murmurs in children leads to many referrals, resulting in unnecessary healthcare costs.

Reported practice patterns in the ambulatory care setting for patients with CHD

INTRODUCTION

In the absence of evidence-based guidelines, paediatric cardiologists monitor patients in the ambulatory care setting largely according to personal, patient, institutional, and/or financial dictates, all of which likely contribute to practice variability. Minimising practice variability may optimise quality of care while incurring lower costs. We sought to describe self-reported practice patterns and physician attitudes about factors influencing their testing strategies using vignettes describing common scenarios in the care of asymptomatic patients with tetralogy of Fallot and d-transposition of the great arteries.

METHODS

We conducted a cross-sectional survey of paediatric cardiologists attending a Continuing Medical Educational conference and at our centre. The survey elicited physician characteristics, self-reported testing strategies, and reactions to factors that might influence their decision to order an echocardiogram.

RESULTS

Of 267 eligible paediatric cardiologists, 110 completed the survey. The majority reported performing an annual physical examination (66-82%), electrocardiogram (74-79%), and echocardiogram (56-76%) regardless of patient age or severity of disease. Other tests (i.e. Holter monitors, exercise stress tests or cardiac MRIs) were ordered less frequently and less consistently. We observed within physician consistency in frequency of test ordering. In vignettes of younger children with mild disease, higher frequency testers were younger than lower frequency testers.

CONCLUSIONS

These results suggest potential practice pattern variability, which needs to be further explored in real-life settings. If clinical outcomes for patients followed by low frequency testers match that of high frequency testers, then room to modify practice patterns and lower costs without compromising quality of care may exist.

[Heart murmur in children less than 2 years-old: looking for a safe and effective referral strategy]

INTRODUCTION

Current guidelines in Spain recommend performing transthoracic echocardiography (TTE) in all children under 2 years of age with a heart murmur. In 2014, the American Paediatric Association published the first appropriate use criteria (AUC) for outpatient paediatric transthoracic echocardiography (TTE) to promote its cost-efficient use. The aim of this article is to analyse the AUC and other clinical factors as predictors of congenital heart disease (CHD) in children less than 2 years of age with a heart murmur, and to develop a safe and efficient referral strategy.

PATIENTS AND METHOD

Case-control study conducted with children less than 2 years of age, referred from Paediatric Primary Care to Paediatric Cardiology during a 4-year study. A predictive model for CHD was determined using multivariate analysis.

RESULTS

A total of 688 patients were included, with 129 (19%) cases of CHD. An age less than 3 months (adjusted odds ratio [ORa] 3.8 [1.5-8.4], p=.030) and fulfilling AUC (ORa 16.3 [9.4-28.3], p<.001) were predictors of CHD. Concurrent infection (ORa 0.6 [0.2-0.8], p<.001) and a negative neonatal screening with pulse oximetry (ORa 0.1 [0.05-0.4], p=.001) decreased the risk of CHD. The referral strategy that included these criteria had a 98% sensitivity, 39% specificity, and positive and negative predictive values of 27% and 99%, respectively. It could not diagnose 2% of CHD (all mild), and showed a 32% TTE reduction rate compared to our current strategy.

CONCLUSION

To refer children less than 3 months old, fulfilling AUC, without a concurrent infection, or without negative neonatal pulse oximetry screening, is a safe and efficient strategy for the management of heart murmur in children under 2 years of age.

Yield of Echocardiogram and Predictors of Positive Yield in Pediatric Patients: A Study in an Urban, Community-Based Outpatient Pediatric Cardiology Clinic

The yield of outpatient echocardiograms varies based on the indication for the echocardiogram and the age of the patient. The purpose of this study was to determine the cumulative yield of outpatient echocardiograms by age group and reason for the test. A secondary aim was to determine the predictors of a positive echocardiogram in an outpatient cardiology clinic at a large community teaching hospital. We retrospectively reviewed the charts of 891 patients who had a first-time echocardiogram between 2011 and 2015. Positive yield was defined as echocardiographic findings that explained the reason for the echocardiogram. The overall positive yield was 8.2%. Children between birth and 3 months of age had the highest yield (34.2%), and children between 12 and 18 years of age had the lowest yield (1%). Patients with murmurs (18.1%) had the highest yield compared with patients with other signs or symptoms. By age group and reason, the highest yields were as follows: 0 to 3 months of age, murmur (39.2%); 4 to 11 months of age, >1 symptom (50%); and 1 to 5 years of age, shortness of breath (66.7%). Based on our study, the overall yield of echocardiograms in the outpatient pediatric setting is low. Age and symptoms should be considered before ordering an echocardiogram.

Managing a "New" Murmur in Healthy Children and Teens

An asymptomatic child with a murmur can be challenging practice management conundrum. Some providers refer all patients with a "new" murmur to a cardiologist, likely resulting in excessive resource utilization and parental anxiety. This study examines whether the prevalence of significant cardiac pathology differs in asymptomatic patients aged 2 to 18 years who were referred for a murmur that was "new" versus those referred for a murmur that was known to exist and followed conservatively during the previous 2 years. Of 473 patients meeting inclusion criteria, 33/473 (7.0%) were diagnosed with cardiac pathology, with 21/357 (5.9%) occurring among "new" murmur referrals and 12/116 (10.3%) occurring among "known" murmur referrals. Notably, 34/357 (9.5%) patients referred for a "new" murmur had no murmur present when assessed by the cardiologist. This study suggests that asymptomatic children with a "new" murmur may be conservatively managed. This may lessen health care resource utilization rates and overall parental anxiety.

Diagnostic Yield of Outpatient Pediatric Echocardiograms: Impact of Indications and Specialty

Multiple reports have shown that echocardiograms are neither cost-effective nor of high diagnostic yield for a number of indications. This study sought to evaluate the impact of indications and provider type on the diagnostic yield of first-time outpatient pediatric echocardiograms. All initial echocardiograms interpreted at our institution from February 2009 to December 2014 were reviewed retrospectively. Positive findings were defined as any abnormality of structure or function. Ordering physicians were grouped as Primary Care, Subspecialist, or Cardiologist. A cost analysis of cardiac consultation versus direct echocardiogram ordering was performed using 2014 Arkansas Medicaid office-based allowables. A total of 7854 echocardiograms had complete data and were included in the study. Median age was 7.2 years (range 2 days to 18.9 years). There were 1179 (15%) abnormal first-time echocardiograms. Diagnostic yields were particularly low for the indications of chest pain (4.9%), syncope (5.3%), and palpitations (9.1%). When ordered by the Cardiology group, echocardiographic yields were increased 35% for all indications (p < 0.001) and 100% for murmurs (p < 0.001) when compared to the Primary Care group. Cost analysis using the model of cardiology consultation rather than direct primary care echocardiogram ordering estimated a 19.6% reduction in medical costs for the most common indication, murmur. The diagnostic yield of outpatient pediatric echocardiograms is low for most indications. Overall, cardiologists had an improved diagnostic yield compared to other ordering physicians. For the indication of murmur, cardiology evaluation before echocardiogram might decrease unnecessary testing and healthcare expenses. This study provides a framework for improving resource utilization in the pediatric population.

The not so innocent heart murmur: a 5-year experience

BACKGROUND

Auckland City Hospital (ACH) established a Heart Murmur Clinic (HMC) with the aim of providing prompt assessment of patients with asymptomatic systolic murmurs. This may lead to early intervention and improved outcomes if significant structural heart disease is detected and reassurance if no significant findings are found. Similar clinics for children have proven beneficial; the benefit of a HMC in an adult population has been difficult to determine.

AIM

To review the clinical demographics and echocardiographic information of patients presenting to our HMC, to assess what proportion of significance structural heart disease had and determine the common structural abnormalities in this population.

METHODS

This is a retrospective review of patients aged ≥15 years presenting to our HMC between March 2010 and December 2015 with an asymptomatic systolic murmur. Patients with previous cardiac surgery or known congenital or valvular heart disease were excluded.

RESULTS

A total of 1221 patients was reviewed over the 5-year period; 980 underwent echocardiography. Significant cardiac disease was detected in 156 patients, with 23 patients requiring surgical intervention over the 5-year period. Significant aortic stenosis (n = 43) and mitral regurgitation (n = 48) were the most common pathologies. Patients > 65 years were more likely to have structural heart disease (16% vs 11%, P < 0.05).

CONCLUSION

Establishing a HMC has allowed the screening of a large number of patients who would otherwise have low priority for assessment. We have identified a large proportion with significant structural disease, which has allowed for early surgical intervention when appropriate and may potentially result in improved patient outcomes.

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.

[Heart murmurs in asymptomatic children: When should you refer?]

Heart murmurs are common in children and adolescents. Although most are innocent, an isolated heart murmur in asymptomatic children may be the sole finding indicating serious heart disease. Historical elements of familial heart disease, cardiovascular symptoms and a well-conducted medical examination can identify children with an increased risk of heart disease. The distinction between an innocent heart murmur and a pathologic heart murmur is not always easy for primary care physicians because most of them have little experience with auscultation searching for congenital heart malformation. Echocardiography provides a definitive diagnosis of heart disease but is not required in case of innocent murmur. Inappropriate pediatric cardiologist and echocardiographic referral leads to useless and expensive examinations, resulting in a work overload for pediatric cardiologists. The objective of this review is to provide the keys to differentiate innocent and pathologic murmurs, and to help physicians decide on the optimal diagnostic strategy.

Prevalence and clinical significance of cardiac murmurs in schoolchildren

OBJECTIVE

To determine the prevalence and clinical significance of heart murmurs detected during heart disease screening among apparently healthy schoolchildren.

DESIGN

Cross-sectional study.

SETTING

32 elementary schools in Dongguan City of China.

PATIENTS

81,213 schoolchildren aged 5-13 years from different elementary schools.

MAIN OUTCOME MEASURES

The prevalence and clinical significance of heart murmurs among schoolchildren.

RESULTS

Murmurs were detected in 2193 schoolchildren (2.7%), of whom 215 had a structural heart disease (SHD). Of patients who had SHD, 198 children had congenital heart disease (CHD), 12 had mitral valve prolapse and 5 had rheumatic heart disease. In patients who had CHD, the most common diagnosis was a ventricular septal defect. With respect to sex, SHDs were equally distributed between males and females. Of the schoolchildren who had a murmur, 1797 (81.9%) had a murmur with the loudness of grade 1 or 2 and 396 (18.1%) had a murmur with the loudness of grades 3-6. The prevalence of SHD fell significantly with increasing age.

CONCLUSIONS

The study suggested that apparently healthy schoolchildren with grade ≤2 cardiac murmurs are least likely to have underlying SHD, especially in those aged ≥10 years. However, echocardiography should be performed in younger schoolchildren with cardiac murmur grade ≥3.

Outcome of children [corrected] with heart murmurs referred from general practice to a paediatrician with expertise in cardiology

BACKGROUND

Heart murmurs are common in children. The majority are detected incidentally, and congenital heart disease is rare. There are no published United Kingdom guidelines for management of children with murmurs in primary care. Common practice is to refer all children for specialist assessment.

AIM

To review outcomes of children with heart murmurs who were referred by general practitioners to a clinic conducted by a paediatrician with expertise in cardiology. Design and setting A retrospective review of children referred by general practitioners to a paediatrician with expertise in cardiology.

METHODS

Hospital records of all children under 17 years of age who attended the clinic during 2011 were reviewed. We excluded children previously seen by any cardiology service.

RESULTS

There were 313 new primary care referrals, with complete records available for 310 children. Of them, 186 (60%) were referred with a murmur: 154 for an asymptomatic murmur alone, and 32 for a murmur plus additional symptoms or family history of congenital heart disease. All underwent echocardiography. Of the patients, 38 (20%) had congenital heart disease. Younger children were more likely to have congenital heart disease. There was no difference between rates of congenital heart disease in children with or without symptoms or a family history.

CONCLUSION

The finding that a large proportion of children referred by general practitioners with asymptomatic heart murmurs have congenital heart disease supports current referral practice on clinical grounds.