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