What is the best approach to manage a 15-year-old male patient with new onset hypertension, 1st-degree atrioventricular (AV) block, inferior T-wave inversion (TWI), and peaked T waves?

Urgent Evaluation for Hyperkalemia and Secondary Hypertension

This 15-year-old with new-onset hypertension, peaked T waves, and ECG abnormalities requires immediate assessment for life-threatening hyperkalemia, followed by comprehensive evaluation for secondary causes of hypertension given his young age.

Immediate Priority: Rule Out Hyperkalemia

• Peaked T waves are the hallmark ECG finding of hyperkalemia and represent a medical emergency requiring immediate serum potassium measurement 1
• First-degree AV block can also occur with hyperkalemia as conduction abnormalities progress 1
• Draw stat basic metabolic panel including potassium, creatinine, and glucose before any other workup 1
• If hyperkalemia is confirmed, initiate emergency treatment protocols immediately before proceeding with further evaluation 2

Secondary Hypertension Workup (After Stabilization)

Given age <30 years, this patient requires comprehensive screening for secondary causes of hypertension, which affects 5-10% of hypertensive patients but is much more common in young patients 1

Essential Initial Laboratory Tests

• Paired morning plasma aldosterone and plasma renin activity (aldosterone-to-renin ratio) - primary aldosteronism is present in 8-20% of resistant hypertension cases and can present with hypokalemia 1
• Complete metabolic panel with attention to potassium (may be low in primary aldosteronism or high in renal disease) 1
• Serum creatinine and eGFR to assess for renal parenchymal disease 1
• Urinalysis and urinary albumin-to-creatinine ratio to detect proteinuria 1
• Fasting glucose and HbA1c 1
• Thyroid-stimulating hormone 1

Critical Physical Examination Findings to Assess

• Radio-femoral pulse delay - suggests aortic coarctation, an important consideration in young hypertensive patients 1
• Abdominal bruits - suggest renovascular disease 1
• Palpation for enlarged kidneys - polycystic kidney disease 1
• Features of Cushing syndrome (fatty deposits, colored striae) 1
• Skin stigmata of neurofibromatosis - associated with pheochromocytoma 1

ECG Findings Interpretation

The inferior T-wave inversion in this young patient warrants cardiac evaluation:

• In adolescents <16 years, anterior T-wave inversion can be a normal variant, but inferior T-wave inversion is not typically benign 2
• T-wave inversions developing with rapid blood pressure reduction can occur without myocardial ischemia 3, but given the clinical context, structural heart disease must be excluded
• Cardiac catheterization is indicated in adolescents with aortic stenosis who develop T-wave inversion at rest over the left precordium if Doppler mean gradient >30 mmHg 2

Recommended Cardiac Imaging

• Echocardiography is essential to evaluate for:
  • Aortic stenosis (given T-wave inversion and young age) 2
  • Left ventricular hypertrophy (common in hypertension) 1
  • Aortic coarctation 1
  • Structural abnormalities 2

Additional Targeted Testing Based on Initial Results

• If aldosterone-to-renin ratio >20 with elevated aldosterone and suppressed renin: proceed to confirmatory testing (saline infusion test) and adrenal CT imaging 1
• If renal dysfunction present: renal ultrasound with Doppler to evaluate for renovascular disease 1
• If episodic symptoms or labile blood pressure: 24-hour urinary metanephrines for pheochromocytoma 1
• Consider polysomnography if obesity and symptoms of obstructive sleep apnea present 1

Antihypertensive Management Approach

While completing diagnostic workup, initiate blood pressure treatment cautiously:

• Start with low-dose ACE inhibitor or ARB - these are preferred in young patients and have favorable effects on organ damage 2
• Add a dihydropyridine calcium channel blocker if needed for blood pressure control 2
• Avoid beta-blockers as first-line therapy in young patients with metabolic concerns 2
• Target systolic BP 120-129 mmHg if well tolerated 2
• Use single-pill combination therapy when multiple agents needed to improve adherence 2

Critical Pitfalls to Avoid

• Do not dismiss peaked T waves - this ECG finding mandates immediate potassium measurement as it can precede life-threatening arrhythmias 1
• Do not perform expensive imaging before completing basic laboratory screening 1
• Do not use short-acting nifedipine for rapid blood pressure reduction due to risk of precipitous drops 2
• Do not delay evaluation for secondary causes - in patients <30 years with hypertension, secondary causes are much more likely than essential hypertension 1
• Delayed diagnosis of secondary hypertension can lead to irreversible vascular remodeling and persistent hypertension even after treating the underlying cause 1