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Significance of cardiac murmurs in detection of congenital heart disease

Published online by Cambridge University Press:  06 September 2019

Guanyang Kang*
Affiliation:
Department of Cardiology, The Fifth People’s Hospital of Dongguan (also called Taiping People’s Hospital of Dongguan), The Dongguan Affiliated Hospital of Medical College of Jinan University, Dongguan, Guangdong, China
Huiqing Zhang
Affiliation:
Department of Pharmacy, The Fifth People’s Hospital of Dongguan (also called Taiping People’s Hospital of Dongguan), The Dongguan Affiliated Hospital of Medical College of Jinan University, Dongguan, Guangdong, China
*
Author for correspondence: G. Kang, Department of Cardiology, The Fifth People’s Hospital of Dongguan (also called Taiping People’s Hospital of Dongguan), The Dongguan Affiliated Hospital of Medical College of Jinan University, 154, Humen Road, Humen, Dongguan 523905, Guandong, China. Tel: +86 0769 85010278; Fax: +86 0769 85010204; E-mail: gykang2008@126.com
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Abstract

Type
Letter to the Editor
Copyright
© Cambridge University Press 2019 

With great interest, we read the study presented by Dilek Dilli and colleagues in a current issue of this journal. Reference Dilli, Dogan and Ozyurt1 The authors reported that pulse oximetry screening is an effective screening tool for CHD in newborns at different altitudes. In this study, physical examination was done in all babies for signs and symptoms related to the cardiovascular system to detect CHD. The presence of central cyanosis, abnormal peripheral pulses, abnormal precordium, murmurs on cardiac auscultation, tachypnea, and chest retractions was considered as positive findings suggesting CHD. Babies with positive clinical findings underwent echocardiography. As a result, echocardiography was performed in 319 babies. The indications were presence of clinical finding (n = 277), test positivity (n = 34), or both (n = 8). They showed that if a murmur (n = 288) was heard, there was a 7.4% (n = 17) chance of there being an underlying cardiac malformation.

Cardiac murmurs are common in asymptomatic babies and represent the most frequent reason for referral to a cardiologist. Reference Pelech2,Reference Smythe, Teixeira, Vlad, Demers and Feldman3 The reported prevalence of cardiac murmurs in apparently healthy children varies widely from 5 to 80% of screened population, depending on the group studied. Reference Etchells, Bell and Robb4,Reference McLaren, Lachman, Pocock and Barlow5 The majority of cardiac murmurs in infants and children are normal or innocent. However, many with CHD are first diagnosed following the detection of a heart murmur incidentally. Identifying these infants and children is important as CHD can cause significant morbidity and may even lead to death without prompt and appropriate treatment. Pulse oximetry has been confirmed as an effective screening modality for CHD. Reference Hu, Ma and Zhao6 However, pulse oximetry detects only those lesions with hypoxia. Most cases of CHD, such as severe left heart obstructive lesions and large left-to-right shunt lesions, cannot be recognised early enough by pulse oximetry. Using pulse oximetry plus cardiac auscultation significantly improved the detection rate of CHD in the early neonatal stage, with high sensitivity and a reasonable false-positive rate. Reference Hu, Ma and Zhao6

Although murmurs on cardiac auscultation have been considered in the study presented by Dilek Dilli and colleagues, the loudness grades of cardiac murmurs have not. However, our previous study showed that schoolchildren with the loudness of grades 3–6 and those younger than 10 years of age should raise a high index of suspicion of CHD and should refer to the echocardiographic examinations. Reference Kang, Xiao and Wang7 Therefore, the loudness grades of cardiac murmurs should be considered in this study. Data should be collected in the baseline clinical characteristics. We are surprised that this potentially important clinical characteristic has not been considered, despite the known increase in CHD risk with louder cardiac murmurs and younger age. Reference Kang, Xiao and Wang7 If the loudness grades of cardiac murmurs have been recorded in the study presented by Dilek Dilli and colleagues, it would have been of utmost interest to consider this factor in this study to evaluate its potential contribution to the CHD risk.

Challenges remain in the judgement of pathological murmurs in newborns, and there are still many CHD patients in developing countries who are not diagnosed in a timely fashion due to insufficiencies in training of clinicians with regard to auscultation. Thus, the importance of training for cardiac auscultation should be emphasised, highlighting the need to improve the ability of paediatricians to accurately discern a heart murmur. This not only decreases the need for unnecessary echocardiographic studies but can also ensure that major CHD can be detected during the neonatal period. It is a challenging work for the paediatricians to distinguish pathological murmurs from the far more common innocent murmurs accurately.

Numerous studies have identified clinical predictors of pathological murmurs, but the absence of abnormal findings does not always guarantee that the diagnosis of CHD can be excluded. Echocardiography remains the gold standard of formal diagnosis. Sending all murmurs for echocardiographic examinations is a poor use of resources. Reference Geva, Hegesh and Frand8 Given the incidence of murmurs in this population, adoption of the strategies of pulse oximetry plus cardiac murmur auscultation would result in considerable cost savings.

We must emphasise that echocardiography should not replace the cardiovascular examination, particularly in the developing countries. As valuable as echocardiography may be, the basic cardiovascular physical examination is still the most appropriate method of screening for CHD.

Acknowledgments

This article is dedicated to my brilliant and beautiful wife, Huiqing Zhang. My wife always comforts and consoles, never complains or interferes, asks nothing, and endures all. She also writes the acknowledgements.

Financial Support

This research received no specific grant from any funding agency, commercial or not-for-profit sectors.

Conflict of Interest

None.

Ethical Standards

The authors assert that all procedures contributing to this work comply with the Helsinki Declaration of 1975, as revised in 2008, and have been approved by the institutional committees (the Ethics Committees of the Fifth People’s Hospital of Dongguan).

Footnotes

*

These two authors equally contributed to this work.

References

Dilli, D, Dogan, V, Ozyurt, BM, et al. Should we start a nationwide screening program for critical congenital heart disease in Turkey? A pilot study on four centres with different altitudes. Cardiol Young 2019: 16.CrossRefGoogle Scholar
Pelech, AN. Evaluation of the pediatric patient with a cardiac murmur. Pediatr Clin North Am 1999; 46: 167188.CrossRefGoogle ScholarPubMed
Smythe, JF, Teixeira, OH, Vlad, P, Demers, PP, Feldman, W. Initial evaluation of heart murmurs: are laboratory tests necessary? Pediatrics 1990; 86: 497500.Google ScholarPubMed
Etchells, E, Bell, C, Robb, K. Does this patient have an abnormal systolic murmur? JAMA 1997; 277: 564571.CrossRefGoogle ScholarPubMed
McLaren, MJ, Lachman, AS, Pocock, WA, Barlow, JB. Innocent murmurs and third heart sounds in black schoolchildren. Br Heart J 1980; 43: 6773.CrossRefGoogle ScholarPubMed
Hu, X, Ma, X, Zhao, Q, et al. Pulse oximetry and auscultation for congenital heart disease detection. Pediatrics 2017, 140: e20171154.CrossRefGoogle ScholarPubMed
Kang, G, Xiao, J, Wang, Y, et al. Prevalence and clinical significance of cardiac murmurs in schoolchildren. Arch Dis Child 2015; 100: 10281031.CrossRefGoogle ScholarPubMed
Geva, T, Hegesh, J, Frand, M. Reappraisal of the approach to the child with heart murmurs: is echocardiography mandatory? Int J Cardiol 1988; 19: 107113.CrossRefGoogle ScholarPubMed