What is the next step in managing an 18-year-old man with hypertension, decreased lower extremity pulses, and a systolic murmur?

Management of Suspected Aortic Coarctation in a Young Adult

The most appropriate next step in management for this 18-year-old man with suspected aortic coarctation is to obtain a cardiovascular MRI or CT scan of the thoracic aorta and intracranial vessels. 1

Clinical Presentation Analysis

The patient presents with classic findings of aortic coarctation:

• Hypertension (140/100 mmHg)
• Upper extremities appearing more muscular than lower extremities
• Decreased femoral, posterior tibial, and dorsalis pedis pulses compared to normal radial pulses
• Grade 2/6 systolic murmur heard over the precordium, anterior chest, and back
• ECG showing left ventricular hypertrophy

These findings strongly suggest aortic coarctation, which is a congenital narrowing of the aorta typically occurring near the ligamentum arteriosum, adjacent to the left subclavian artery origin.

Diagnostic Algorithm

1. Imaging of the thoracic aorta

   • Cardiovascular MRI or CT scan is the gold standard diagnostic test 1
   • This will provide complete evaluation of the thoracic aorta and intracranial vessels
   • Will help identify the exact location and severity of coarctation
   • Can also detect associated anomalies like bicuspid aortic valve or intracranial aneurysms

2. Echocardiography with Doppler

   • Should be performed to assess:
     • Coarctation gradient
     • Left ventricular size and function
     • Associated cardiac abnormalities (bicuspid aortic valve, VSD)
     • Forward diastolic flow in the descending aorta 1

3. Blood pressure measurements

   • Compare upper and lower extremity blood pressures
   • A systolic pressure difference >20 mmHg suggests significant coarctation 2

Treatment Considerations

Once diagnosis is confirmed, treatment options include:

1. Intervention criteria (Class I recommendations) 1:

   • Peak-to-peak coarctation gradient ≥20 mmHg
   • Peak-to-peak gradient <20 mmHg with significant anatomic narrowing and collateral flow

2. Intervention type:

   • Decision between percutaneous catheter intervention vs. surgical repair should be made by a team of ACHD (Adult Congenital Heart Disease) specialists 1
   • Factors influencing choice include:
     • Length of coarctation segment
     • Presence of aortic arch hypoplasia
     • Associated cardiac defects

3. Medical therapy:

   • Beta-blockers are first-line medications for hypertension control in coarctation 1
   • ACE inhibitors or ARBs are also appropriate first-line options
   • Choice may be influenced by aortic root size and presence of aortic regurgitation

Follow-up Requirements

After diagnosis and treatment:

• Lifelong cardiology follow-up is mandatory 1
• At least yearly cardiology evaluations
• Repeat MRI/CT imaging at intervals of 5 years or less
• Aggressive management of blood pressure and cardiovascular risk factors

Important Caveats

1. Don't miss associated conditions:

   • Bicuspid aortic valve (common association)
   • Intracranial aneurysms (require screening)
   • Ventricular septal defects
   • Mitral valve abnormalities

2. Avoid misdiagnosis:

   • Subclavian artery stenosis can present similarly with blood pressure differences 3
   • Ensure blood pressure is measured in both arms and legs

3. Complications to monitor:

   • Persistent hypertension (common even after repair)
   • Aortic aneurysm formation
   • Recurrent coarctation
   • Premature coronary artery disease

The diagnosis and management of aortic coarctation require specialized care. Early detection and appropriate intervention can significantly improve long-term outcomes and reduce morbidity and mortality associated with this condition.