Anaesthetist's evaluation of a child with a heart murmur

Abstract

Although between 50% and 85% of children may have a heart murmur, most heart murmurs are innocent. Murmurs can occur because of children's high cardiac output and small vessels, branching at acute angles, which promote turbulent flow. Innocent murmurs can be described according to seven characteristics, but not all murmurs adhere to these rules. There are seven different types of innocent murmurs. An innocent murmur can often be diagnosed by taking a history and conducting an examination. An electrocardiogram is helpful in assessing left ventricular mass if aortic stenosis (AS) or hypertrophic cardiomyopathy (HOCM) is anticipated. If uncertainty exists, the differential diagnosis should guide decision-making. If a high-risk lesion, such as an AS or HOCM is anticipated, it should be assessed first, while a more benign lesion, such as an atrial septal defect, could be evaluated by a cardiologist after surgery. The type of surgery is also a deciding factor. Any child under one year of age has a much higher risk of having pathology which may be severe, and will need to be referred before surgery. Endocarditis prophylaxis and the risk of air emboli should always be considered.