Hypertension In Childhood

Introduction

Hypertension in childhood is a critical topic for MCCQE1 preparation, as it's becoming increasingly prevalent in Canadian pediatric populations. This comprehensive guide will cover essential aspects of childhood hypertension, focusing on Canadian guidelines and practices to help you excel in your MCCQE1 exam.

Epidemiology in Canada

• Prevalence of hypertension in Canadian children: 3-5%
• Higher rates observed in:
  • Indigenous populations
  • Children with obesity
  • Adolescents

Definition and Classification

Hypertension in children is defined differently from adults. In Canada, we follow these guidelines:

Classification

1. Primary (Essential) Hypertension

   • Most common in adolescents
   • Often associated with obesity and family history

2. Secondary Hypertension

   • More common in younger children
   • Underlying causes include renal, cardiovascular, or endocrine disorders

Etiology

Clinical Presentation

Children with hypertension may be asymptomatic or present with:

• Headaches
• Visual disturbances
• Fatigue
• Chest pain
• Shortness of breath

Diagnosis

Diagnostic Approach

1. Confirm hypertension with repeated measurements
2. Assess for end-organ damage
3. Evaluate for underlying causes
4. Consider 24-hour ambulatory BP monitoring

Management

Management of childhood hypertension in Canada follows a stepped approach:

1. Lifestyle modifications

   • Healthy diet (emphasize Canadian Food Guide)
   • Regular physical activity
   • Weight management

2. Pharmacological treatment

   • Indicated if BP remains elevated despite lifestyle changes
   • First-line agents in Canada:
     • ACE inhibitors
     • Angiotensin receptor blockers (ARBs)
     • Calcium channel blockers

Complications

• Left ventricular hypertrophy
• Retinopathy
• Cognitive impairment
• Progression to adult hypertension

Canadian Guidelines

The Canadian Hypertension Society provides specific guidelines for managing pediatric hypertension:

1. Annual BP screening for children ≥3 years old
2. Use of Canadian-specific BP percentile charts
3. Emphasis on non-pharmacological management as first-line treatment
4. Recommendation for specialist referral in complex cases

Key Points to Remember for MCCQE1

• Definition changes at age 13 in Canadian guidelines
• Secondary causes more common in younger children
• Asymptomatic presentation is frequent
• Routine BP screening is crucial
• Lifestyle modifications are first-line treatment
• Canadian-specific BP percentile charts should be used
• Consider ethnic variations in risk (e.g., Indigenous populations)

Sample Question

Question

A 14-year-old boy presents for a routine check-up. He is asymptomatic but has a family history of hypertension. His blood pressure is measured as 132/82 mmHg on three separate occasions. His BMI is at the 85th percentile for age and sex. Which one of the following is the most appropriate next step in management?

• A. Start ACE inhibitor therapy
• B. Order renal ultrasound
• C. Recommend lifestyle modifications
• D. Refer to a pediatric cardiologist
• E. No further action needed as BP is normal for age

Explanation

The correct answer is:

• C. Recommend lifestyle modifications

Explanation: According to Canadian guidelines, for children ≥13 years old, hypertension is defined as BP ≥130/80 mmHg. This patient's BP of 132/82 mmHg meets the criteria for hypertension. Given his age, asymptomatic presentation, and BMI at the 85th percentile, primary hypertension is likely. The most appropriate first step is to recommend lifestyle modifications, including diet changes, increased physical activity, and weight management. Pharmacological treatment (A) is not first-line without trying lifestyle changes. A renal ultrasound (B) is not immediately necessary without signs of secondary hypertension. Referral to a specialist (D) is not needed at this stage. The BP is not normal for age (E), so action is required.

References

1. Dionne, J. M., et al. (2020). Hypertension Canada's 2020 Guidelines for the Prevention, Diagnosis, Treatment, and Follow-up of Hypertension in Children and Adolescents. Canadian Journal of Cardiology, 36(12), 1974-1981.

2. Canadian Paediatric Society. (2018). Hypertension in children and adolescents. Paediatrics & Child Health, 23(1), 12-14.

3. Statistics Canada. (2019). Blood pressure of children and youth, 2012 to 2015. https://www150.statcan.gc.ca/n1/pub/82-625-x/2016001/article/14657-eng.htm (opens in a new tab)

4. Canadian Task Force on Preventive Health Care. (2020). Recommendations on screening for hypertension in children and adolescents. CMAJ, 192(41), E1182-E1191.

5. Health Canada. (2019). Canada's Food Guide. https://food-guide.canada.ca/en/ (opens in a new tab)