What is the next step in diagnosing a child with hypertension and a systolic ejection murmur?

From the Guidelines

The most appropriate next step in diagnosis for this 6-year-old girl is measurement of blood pressure in the upper and lower extremities (option A). This child presents with significantly elevated blood pressure (160/100 mm Hg) and a systolic ejection murmur that radiates to the back, which strongly suggests coarctation of the aorta. Coarctation is a narrowing of the aorta that typically occurs just distal to the left subclavian artery, causing hypertension in the upper extremities and decreased blood pressure in the lower extremities. Comparing blood pressure measurements between arms and legs is a simple, non-invasive first step that can quickly provide diagnostic information. If coarctation is present, the blood pressure will be higher in the upper extremities than in the lower extremities, and there will typically be weak or delayed femoral pulses. This finding would prompt further imaging studies such as echocardiography to confirm the diagnosis. Early detection and treatment of coarctation are important to prevent long-term complications of hypertension such as left ventricular hypertrophy, heart failure, and stroke. According to the American Heart Association guidelines 1, children who show elevated blood pressure on repeated measurement should also have the blood pressure measured in the leg as a screen for coarctation of the aorta.

The clinical practice guideline for screening and management of high blood pressure in children and adolescents also recommends measuring blood pressure in the upper and lower extremities in children with elevated blood pressure 1. Additionally, the guideline states that children with suspected coarctation of the aorta should undergo further evaluation, including imaging studies such as echocardiography.

In contrast, the other options are not the most appropriate next step in diagnosis. Measuring serum catecholamine concentrations (option B) may be useful in diagnosing certain conditions such as pheochromocytoma, but it is not the most likely cause of this child's symptoms. Renal ultrasonography (option C) may be useful in evaluating renal disease, but it is not the most appropriate initial test in this case. Urinalysis (option D) may be useful in evaluating for secondary causes of hypertension, but it is not the most important initial test. Observation and follow-up in 1 month (option E) is not appropriate given the significantly elevated blood pressure and the potential for coarctation of the aorta.

It is worth noting that the most recent guidelines from 2019 1 also emphasize the importance of measuring blood pressure in the upper and lower extremities in children with elevated blood pressure, and recommend further evaluation with imaging studies such as echocardiography if coarctation is suspected.

Key points to consider in this case include:

• The child's significantly elevated blood pressure and systolic ejection murmur that radiates to the back, which suggests coarctation of the aorta.
• The importance of measuring blood pressure in the upper and lower extremities to diagnose coarctation of the aorta.
• The need for further evaluation with imaging studies such as echocardiography if coarctation is suspected.
• The potential long-term complications of hypertension, such as left ventricular hypertrophy, heart failure, and stroke, and the importance of early detection and treatment.

From the Research

Diagnosis of Hypertension in a 6-year-old Girl

The patient's symptoms and physical examination results suggest a possible diagnosis of coarctation of the aorta, which is a congenital condition characterized by a narrowing of the aorta. The presence of a grade 3/6 systolic ejection murmur heard best along the left sternal border and radiating to the back, along with high blood pressure, supports this diagnosis 2.

Key Findings and Next Steps

• The patient's blood pressure is significantly elevated, which is a common finding in coarctation of the aorta 3.
• The presence of a systolic murmur and the location of the murmur are consistent with coarctation of the aorta 2, 4.
• To confirm the diagnosis, measurement of blood pressure in the upper and lower extremities is crucial, as it can help identify a pressure gradient between the two, which is a hallmark of coarctation of the aorta 2, 5.

Most Appropriate Next Step

The most appropriate next step in diagnosis is to measure blood pressure in the upper and lower extremities, as this can help confirm the presence of a pressure gradient and support the diagnosis of coarctation of the aorta 2, 5. This is option A) Measurement of blood pressure in the upper and lower extremities.

Rationale for Other Options

• Option B) Measurement of serum catecholamine concentrations is not directly relevant to the diagnosis of coarctation of the aorta.
• Option C) Renal ultrasonography may be useful in evaluating the patient's kidneys, but it is not the most appropriate next step in diagnosing coarctation of the aorta.
• Option D) Urinalysis may be useful in evaluating the patient's overall health, but it is not directly relevant to the diagnosis of coarctation of the aorta.
• Option E) Observation and follow-up in 1 month is not appropriate, as the patient's high blood pressure and murmur require prompt evaluation and diagnosis 3.