Systemic Hypertension in Children
Introduction to Systemic Hypertension in Children
Systemic hypertension in children is defined as persistently elevated blood pressure (BP) above the 95th percentile for age, sex, and height. It is an increasingly recognized problem in pediatrics, with significant long-term health implications.
Key points:
- Definition: BP ≥95th percentile for age, sex, and height on three or more occasions
- Classification: Primary (essential) or Secondary hypertension
- Importance: Risk factor for cardiovascular disease in adulthood
- Challenges: Often asymptomatic, requiring active screening for detection
Epidemiology of Pediatric Hypertension
The prevalence of hypertension in children and adolescents has been increasing in recent years, largely due to the obesity epidemic.
1. Prevalence
- Overall prevalence: 3-5% in children and adolescents
- Higher in certain populations: obese children (prevalence up to 25%)
2. Age Distribution
- Infants and young children: More likely to have secondary hypertension
- Adolescents: Increasing prevalence of primary hypertension
3. Risk Factors
- Obesity
- Family history of hypertension
- Low birth weight
- Ethnic background (higher prevalence in African American children)
- Sedentary lifestyle
- High sodium intake
4. Trends
- Increasing prevalence over the past few decades
- Parallels the rise in childhood obesity rates
- Growing awareness and improved screening practices
Etiology of Pediatric Hypertension
The causes of hypertension in children can be broadly categorized into primary and secondary hypertension:
1. Primary (Essential) Hypertension
- Most common in adolescents and older children
- Often associated with obesity and family history
- Multifactorial: genetic predisposition, environmental factors
2. Secondary Hypertension
More common in younger children and infants. Causes include:
Renal Causes
- Renal parenchymal diseases (e.g., glomerulonephritis, polycystic kidney disease)
- Renal artery stenosis
- Congenital renal anomalies
Cardiovascular Causes
- Coarctation of the aorta
- Aortic stenosis
Endocrine Causes
- Cushing syndrome
- Pheochromocytoma
- Congenital adrenal hyperplasia
- Hyperthyroidism
Other Causes
- Medications (e.g., corticosteroids, oral contraceptives)
- Central nervous system tumors
- Sleep-disordered breathing
Diagnosis of Pediatric Hypertension
Diagnosing hypertension in children requires careful measurement and interpretation of blood pressure values:
1. Blood Pressure Measurement
- Use appropriate cuff size: bladder width should cover 40% of arm circumference
- Multiple measurements on different occasions
- Consider ambulatory blood pressure monitoring (ABPM) for confirmation
2. Classification
- Normal: <90th percentile
- Elevated: ≥90th to <95th percentile or 120/80 mmHg to <95th percentile (whichever is lower)
- Stage 1 hypertension: ≥95th percentile to <95th percentile + 12 mmHg, or 130/80 to 139/89 mmHg (whichever is lower)
- Stage 2 hypertension: ≥95th percentile + 12 mmHg, or ≥140/90 mmHg (whichever is lower)
3. Diagnostic Workup
- Complete history and physical examination
- Laboratory tests: CBC, electrolytes, BUN, creatinine, lipid profile, urinalysis
- Imaging: Renal ultrasound, echocardiogram
- Additional tests based on suspected etiology: plasma renin activity, aldosterone, thyroid function tests
4. Evaluation for Target Organ Damage
- Echocardiogram: Left ventricular hypertrophy
- Retinal examination: Retinopathy
- Urine microalbumin: Early renal damage
Clinical Presentation of Pediatric Hypertension
Hypertension in children is often asymptomatic and discovered during routine check-ups. However, some children may present with symptoms:
1. Common Symptoms
- Headache
- Fatigue
- Blurred vision
- Epistaxis (nosebleeds)
2. Symptoms Suggestive of Secondary Causes
- Failure to thrive (renal disease)
- Sweating, palpitations (pheochromocytoma)
- Weak femoral pulses (coarctation of aorta)
- Cushingoid features (Cushing syndrome)
3. Signs of Hypertensive Emergency
- Severe headache
- Confusion
- Seizures
- Visual changes
4. Physical Examination Findings
- Elevated blood pressure
- Obesity
- Acanthosis nigricans (insulin resistance)
- Cafe-au-lait spots (neurofibromatosis)
- Abdominal masses
- Heart murmurs
Management of Pediatric Hypertension
The management of hypertension in children involves both non-pharmacological and pharmacological approaches:
1. Non-pharmacological Management
- Weight reduction in obese children
- Increased physical activity
- Dietary modifications: DASH diet, sodium restriction
- Stress reduction techniques
- Smoking cessation (in adolescents)
2. Pharmacological Management
Indications for drug therapy:
- Symptomatic hypertension
- Secondary hypertension
- Hypertensive target-organ damage
- Diabetes (types 1 and 2)
- Persistent hypertension despite lifestyle modifications
Commonly used medications:
- ACE inhibitors: e.g., Lisinopril, Enalapril
- Angiotensin receptor blockers (ARBs): e.g., Losartan
- Calcium channel blockers: e.g., Amlodipine
- Beta-blockers: e.g., Metoprolol
- Diuretics: e.g., Hydrochlorothiazide
3. Management of Hypertensive Emergency
- Immediate hospitalization
- Gradual reduction of blood pressure
- Intravenous antihypertensive medications: e.g., Labetalol, Nicardipine
4. Follow-up and Monitoring
- Regular blood pressure measurements
- Monitoring for medication side effects
- Periodic assessment of target organ damage
- Adjusting treatment based on growth and development
Complications of Pediatric Hypertension
Untreated or poorly controlled hypertension in children can lead to various complications:
1. Cardiovascular Complications
- Left ventricular hypertrophy
- Accelerated atherosclerosis
- Increased risk of coronary artery disease in adulthood
2. Renal Complications
- Microalbuminuria
- Progressive renal dysfunction
3. Neurological Complications
- Cognitive impairment
- Increased risk of stroke
4. Ocular Complications
- Hypertensive retinopathy
5. Metabolic Complications
- Insulin resistance
- Dyslipidemia
6. Long-term Consequences
- Persistent hypertension into adulthood
- Increased cardiovascular morbidity and mortality
Objective QnA: Heart Failure in Children
- Question: What is the most common cause of heart failure in infants? Answer: Congenital heart defects
- Question: Which sign is most specific for heart failure in infants? Answer: Hepatomegaly
- Question: What is the gold standard for assessing ventricular function in pediatric heart failure? Answer: Echocardiography
- Question: Which medication class is the cornerstone of treatment for systolic heart failure in children? Answer: ACE inhibitors
- Question: What is the most common cause of acquired heart failure in children in developed countries? Answer: Cardiomyopathy
- Question: Which biomarker is used to diagnose and monitor heart failure in children? Answer: B-type natriuretic peptide (BNP) or NT-proBNP
- Question: What is the primary goal of treatment for acute heart failure in children? Answer: To improve cardiac output and tissue perfusion
- Question: Which inotropic agent is commonly used in acute heart failure in children? Answer: Milrinone
- Question: What is the most common type of cardiomyopathy in children? Answer: Dilated cardiomyopathy
- Question: Which electrolyte abnormality should be closely monitored and corrected in children with heart failure? Answer: Hypokalemia
- Question: What is the role of beta-blockers in pediatric heart failure? Answer: To improve long-term ventricular function and survival
- Question: Which imaging modality is used to assess for myocardial fibrosis in pediatric heart failure? Answer: Cardiac MRI with late gadolinium enhancement
- Question: What is the New York Heart Association (NYHA) equivalent used to classify heart failure in young children? Answer: Ross classification
- Question: Which viral infection is a common cause of myocarditis leading to heart failure in children? Answer: Coxsackievirus B
- Question: What is the first-line diuretic used in pediatric heart failure? Answer: Furosemide
- Question: Which nutritional supplement is often recommended for children with heart failure? Answer: Vitamin D
- Question: What is the definition of cardiogenic shock in children? Answer: Inadequate tissue perfusion due to cardiac dysfunction despite adequate intravascular volume
- Question: Which device is used for mechanical circulatory support in children as a bridge to transplantation? Answer: Ventricular assist device (VAD)
- Question: What is the most common indication for heart transplantation in children? Answer: Cardiomyopathy
- Question: Which medication is used to reduce pulmonary vascular resistance in children with heart failure? Answer: Sildenafil
- Question: What is the role of cardiac resynchronization therapy in pediatric heart failure? Answer: To improve ventricular synchrony and cardiac output in select patients
- Question: Which genetic syndrome is associated with hypertrophic cardiomyopathy in children? Answer: Noonan syndrome
- Question: What is the most common arrhythmia associated with heart failure in children? Answer: Atrial tachycardia
- Question: Which scoring system is used to prioritize pediatric patients for heart transplantation? Answer: The Berlin Heart Institute score
- Question: What is the role of angiotensin receptor-neprilysin inhibitors (ARNI) in pediatric heart failure? Answer: Emerging therapy for select patients with systolic dysfunction
- Question: Which congenital heart defect commonly leads to right ventricular failure? Answer: Tetralogy of Fallot with pulmonary regurgitation
- Question: What is the recommended daily fluid intake for children with heart failure? Answer: Restricted to 75-100% of normal daily requirements
- Question: Which imaging modality is used to assess cardiac iron overload in children with thalassemia? Answer: T2* cardiac MRI
- Question: What is the most common cause of death in children with heart failure? Answer: Progressive pump failure
- Question: Which medication is used to treat protein-losing enteropathy in children with heart failure? Answer: Budesonide
Further Reading
- Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents
- Pediatric Hypertension: Diagnosis, Evaluation, and Treatment
- Hypertension in children and adolescents: epidemiology and natural history
- Hypertension in Children and Adolescents: Definition, Pathophysiology, Risk Factors, and Long-Term Sequelae
- The Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents