Peds Ch 41 - Heart: Common acquired cardiovascular disorders

Kawasaki disease, rheumatic fever, cardiomyopathy, ineffective endocarditis, hypertension, obesity/hyperlipidemia

Kawasaki Disease

• Acute febrile illness with systemic vasculitis (inflammation of blood vessels)

• Affects all vessels, especially coronary arteries

• Major risk: coronary artery aneurysms → thrombosis → myocardial infarction

• aka = Mucocutaneous Lymph Node Syndrome

Kawasaki Disease - Etiology & Risk Factors

• Unknown cause

• Likely:

  • Genetic predisposition

  • Possible infectious trigger

• Not contagious

• More common:

  • < 5 years old (76%)

  • Males

  • Winter & spring

  • Asian/Pacific Island descent

Kawasaki Disease - Diagnosis

• Diagnosis of exclusion (no specific test)

Required Criteria

• Fever ≥ 5 days (>100.4°F / 39°C)
  PLUS 4 of the following:

1. Extremity changes (redness, swelling, peeling)

2. Polymorphous rash

3. Bilateral conjunctivitis (no pus)

4. Oral changes (strawberry tongue, cracked lips)

5. Cervical lymphadenopathy (>1.5 cm)

Kawasaki Disease - Acute Phase (Week 1)

• High fever

• Irritability

• Inflammation → joint pain

Kawasaki Disease - Subacute Phase (Weeks 2–3)

• Peeling skin (hands/feet)

• ↑ Platelets (thrombocytosis) → ↑ clot risk

• Risk of:

  • Coronary aneurysms

  • Thrombus → MI

Kawasaki Disease - Lab Findings (Supportive, not diagnostic)

• ↑ WBC (leukocytosis)

• ↑ Platelets (thrombocytosis)

• ↑ ESR & CRP (inflammation)

• ↑ liver enzymes

• Mild anemia

Kawasaki Disease - Complications

• Coronary artery aneurysms (15–25%)

• Thrombosis

• Myocardial ischemia/infarction

Kawasaki Disease - Treatment

Main Goals

• Reduce inflammation

• Prevent coronary damage

Primary Treatments

1. IVIG (Intravenous Immunoglobulin)

   • Dose: 2 g/kg

   • May repeat if fever persists

2. Aspirin Therapy

   • High dose: 80–100 mg/kg/day (acute phase)

   • Then low dose: 3–5 mg/kg/day

   • Continued 6–8 weeks or longer if coronary involvement

Kawasaki Disease - Supportive Care

• Antipyretics (fever control)

• IV fluids (hydration)

• Monitor intake (child often irritable)

Kawasaki Disease - Prognosis

• With treatment:

  • ~90% have normal coronary arteries by 6–18 months

• Without treatment:

  • High risk of cardiac complications

Rheumatic Fever

• Autoimmune inflammatory disease

• Occurs after untreated group A beta-hemolytic streptococcal (GAS) pharyngitis

• Causes inflammation in:

  • Heart (most serious)

  • Joints

  • Brain

  • Blood vessels

Rheumatic Fever - Cause & Pathophysiology

• Trigger: strep throat infection

• Occurs about ~10 days after infection

• Immune system overreacts → attacks body tissues

• Leads to progressive damage to heart valves (especially left side)

Rheumatic Fever - Who Is Affected

• Ages: 6–15 years (peak ~8 years)

• Higher risk:

  • Genetically susceptible children

  • Limited access to healthcare (untreated strep)

Rheumatic Fever - Diagnosis: Jones Criteria (

Diagnosis requires:

• 2 major OR

• 1 major + 2 minor

Rheumatic Fever - Major Manifestations

• Carditis (most serious)

  • Often mitral valve insufficiency

• Polyarthritis

  • Painful, swollen joints (migratory)

• Sydenham chorea

  • Involuntary movements

  • Facial grimacing, poor coordination

• Erythema marginatum

  • Pink, non-itchy rash (trunk)

• Subcutaneous nodules

  • Firm nodules over bony areas

Rheumatic Fever - Minor Manifestations

• Fever (>38.5°C)

• Arthralgia (joint pain)

• ↑ ESR / CRP

• Prolonged PR interval (ECG)

Rheumatic Fever - Key Clinical Features

• Polyarthritis → common first sign

• Carditis (~50%) → can cause permanent damage

• Chorea (~10%) → worsens with stress

• Rash (rare but specific) → erythema marginatum

Rheumatic Fever - Lab & Diagnostic Findings

• ↑ ASO titer → confirms recent strep infection

• ↑ ESR, CRP (inflammation)

• Echocardiogram → essential

  • Evaluates heart valve damage

Rheumatic Fever - Complications

• Chronic rheumatic heart disease

• Valve damage (mitral most common)

• Possible need for:

  • Valve repair

  • Valve replacement

Rheumatic Fever - Antibiotics

• Penicillin (IM or oral for 10 days)

• Started immediately after labs obtained

Rheumatic Fever - Anti-inflammatory Therapy

• NSAIDs → reduce joint pain & inflammation

• Steroids → for severe carditis (controversial)

Rheumatic Fever - Chorea Management

Medications:

• Phenobarbital

• Diazepam

Rheumatic Fever - Prognosis

• Depends on heart involvement

• Valve damage may:

  • Progress over time

  • Appear later even if absent initially

• Requires lifelong cardiology follow-up

Cardiomyopathy

• Disease of the heart muscle

• Major cause of heart failure (HF) in children

• #1 cause of heart transplant in children >1 year

• Causes:

  • Primary: genetic, neuromuscular

  • Secondary: infection, toxins, structural disease, metabolic disorders

Dilated Cardiomyopathy

• Enlarged (dilated) left ventricle

• ↓ systolic function (weak contraction)

• Often → mitral valve regurgitation

Dilated Cardiomyopathy - Key Causes

• Genetic (up to 50%)

• Myocarditis (usually viral) → most common inflammatory cause

• Cardiotoxic drugs (chemotherapy)

• Radiation therapy

Dilated Cardiomyopathy - Pathophysiology

• Weak heart muscle → poor pumping

• Blood backs up → heart failure symptoms

• LV dilation → valve stretching → regurgitation

Dilated Cardiomyopathy - Children CM

• Exercise intolerance

• Dyspnea on exertion

• Chest pain

• Palpitations

• Syncope

• Severe Cases

  • Cardiogenic shock (rapid onset)

Dilated Cardiomyopathy - Infants CM

• Respiratory distress

• Poor feeding

• Fatigue

Dilated Cardiomyopathy - Diagnostic Findings

• CXR:

  • Cardiomegaly

  • Pulmonary congestion/edema

• ECG:

  • Sinus tachycardia

• Echocardiogram (KEY):

  • Dilated ventricle

  • ↓ systolic function

Dilated Cardiomyopathy - Medication

• ACE inhibitors

• Beta-blockers

• RAAS inhibition
  → Goal: manage heart failure symptoms

Dilated Cardiomyopathy - Advanced Therapy

• ECMO (temporary support)

• VAD (ventricular assist device)

• Heart transplant (if severe, refractory)

Dilated Cardiomyopathy - Prognosis

• ~50% recover within first year (if survival occurs)

• Remaining:

  • 25% → improved but abnormal function

  • 25% → severe persistent dysfunction

• Outcome depends on:

  • Age

  • Cause

  • Overall health

Hypertrophic Cardiomyopathy

• Thickened (hypertrophied) left ventricle

• Small (nondilated) ventricular cavity

• Hypercontractile systolic function

• Impaired relaxation (diastolic dysfunction)

Hypertrophic Cardiomyopathy - Key Feature

In ~20%:

• Left ventricular outflow tract (LVOT) obstruction

• Caused by mitral valve moving toward septum

• → Called Hypertrophic Obstructive Cardiomyopathy (HOCM)In ~20%:

  • Left ventricular outflow tract (LVOT) obstruction

  • Caused by mitral valve moving toward septum

  • → Called Hypertrophic Obstructive Cardiomyopathy (HOCM)

Hypertrophic Cardiomyopathy - Etiology

• Autosomal dominant genetic disorder

• Most common inherited cardiac condition

• Up to 80% have a family history
  → Family screening required

Hypertrophic Cardiomyopathy - Major Risk

• Most common cause of sudden cardiac death in healthy children/athletes

• Death usually due to:

  • Arrhythmias

  • ↑ myocardial oxygen demand

Hypertrophic Cardiomyopathy - Special Case

Infants of diabetic parents:

• Develop temporary HCM due to hyperinsulinism

• Usually resolves within 1 year

Hypertrophic Cardiomyopathy - CM

• Exercise intolerance

• Syncope (fainting)

• Dyspnea

• Chest pain

Infants

• Signs of heart failure

Important

• Many children are asymptomatic

Hypertrophic Cardiomyopathy - Diagnosis

Echocardiogram (KEY)

• Shows LV hypertrophy

• May show obstruction

Hypertrophic Cardiomyopathy - Beta-blockers

(FIRST LINE)

• Example: metoprolol

• Effects:

  • ↓ heart rate

  • ↓ contractility

  • ↓ oxygen demand

  • ↑ ventricular filling

Hypertrophic Cardiomyopathy - Calcium Channel Blockers

• Example: verapamil

• Improve diastolic filling

Hypertrophic Cardiomyopathy - Advanced Treatment

• Surgical removal of obstruction (if severe)

• Implantable Cardioverter-Defibrillator (ICD)

  • For high-risk patients

  • Prevents sudden cardiac death

Hypertrophic Cardiomyopathy - Nursing / Safety Considerations

• Avoid dehydration

  • ↓ preload → worsens obstruction

• Monitor for:

  • Syncope

  • Arrhythmias

• Encourage family screening

Restrictive Cardiomyopathy

• Stiff (noncompliant) ventricles

• Impaired filling during diastole

• Normal (or near normal) systolic function

• Normal wall thickness

Restrictive Cardiomyopathy - Key Pathophysiology

• Heart cannot relax properly

• ↓ ventricular filling → ↓ preload

• → ↓ cardiac output

• Leads to heart failure (HF)

Restrictive Cardiomyopathy - Causes

• Idiopathic (unknown)

• Can be associated with:

  • Other systemic diseases

• Rare

  • Accounts for ~2.5–5% of cardiomyopathies

Restrictive Cardiomyopathy - CM

(Often related to poor filling & HF)

• Exercise intolerance

• Fatigue

• Dyspnea

• Signs of heart failure

  • May resemble right-sided HF:

    • Hepatomegaly

    • Edema

Restrictive Cardiomyopathy - Key Concept

• “Normal squeeze, poor filling”
  → opposite problem of dilated cardiomyopathy

Restrictive Cardiomyopathy - Diagnosis

Echocardiogram (KEY)

• Normal systolic function

• Impaired diastolic filling

Prognosis

• Poor

• ~50% mortality within 2 years

Restrictive Cardiomyopathy - Management

• Mainly supportive

• Focus on:

  • Managing HF symptoms

• May ultimately require:

  • Heart transplant

Arrhythmogenic Right Ventricular Cardiomyopathy

• Rare inherited heart disease

• Characterized by:

  • Fibrofatty replacement of the right ventricle

• Leads to:

  • Electrical instability → ventricular arrhythmias

Arrhythmogenic Right Ventricular Cardiomyopathy - Key Pathophysiology

• Heart muscle cells die and are replaced with fat & fibrous tissue

• Disrupts electrical conduction

• → Causes ventricular tachyarrhythmias

• Often triggered by exercise

Arrhythmogenic Right Ventricular Cardiomyopathy - Major Risk

• Sudden cardiac death, especially in:

  • Young people

  • Athletes

Arrhythmogenic Right Ventricular Cardiomyopathy - CM

• Palpitations

• Syncope (fainting)

• Chest pain

• Sudden cardiac arrest (especially during exercise)

⚠ RED FLAG:

• Any symptoms during exercise → must be evaluated immediately

Arrhythmogenic Right Ventricular Cardiomyopathy - Diagnosis

• Patient & family history

• 12-lead ECG

• Echocardiogram

• Cardiac MRI (important for structural changes)

Arrhythmogenic Right Ventricular Cardiomyopathy - Management

(No cure — focus on prevention of death)

Lifestyle

• Restrict physical activity/exercise

Prognosis

• Variable but risk of sudden death is significant

• Requires lifelong monitoring

Arrhythmogenic Right Ventricular Cardiomyopathy - Medications

• Beta-blockers

• Antiarrhythmic drugs

Arrhythmogenic Right Ventricular Cardiomyopathy - Device Therapy

• Implantable Cardioverter-Defibrillator (ICD)

  • Most important intervention

  • Prevents sudden cardiac death

Cardiomyopathy Comparison Table

Feature	Dilated (DCM)	Hypertrophic (HCM)	Restrictive (RCM)	ARVC
Main Problem	Weak, stretched heart	Thick, stiff heart	Stiff, noncompliant heart	Electrical instability
Ventricle Size	Dilated (enlarged)	Thick, small cavity	Normal size	RV replaced by fat
Systolic Function	↓ Decreased	↑/Normal (hypercontractile)	Normal	Variable
Diastolic Function	↓	↓	↓ (MAIN issue)	Variable
Key Patho	Poor contraction	Poor relaxation + obstruction	Poor filling	Fibrofatty RV replacement
Most Common Cause	Genetic, myocarditis	Genetic (autosomal dominant)	Idiopathic/systemic	Genetic
Classic Symptoms	HF, fatigue, dyspnea	Syncope, chest pain, exercise intolerance	HF symptoms	Palpitations, syncope
Infant Symptoms	Poor feeding, fatigue	HF symptoms	HF symptoms	Rare early
Hallmark Clue	Big weak heart	Thick heart + sudden death	Normal squeeze, poor filling	Exercise → arrhythmia
Major Risk	Heart failure	Sudden cardiac death	Severe HF, high mortality	Sudden cardiac death (athletes)
Diagnosis	Echo: dilated LV	Echo: thick LV	Echo: stiff ventricles	ECG + MRI
Treatment	HF meds, transplant	Beta-blockers, ICD	Supportive, transplant	ICD, avoid exercise
Prognosis	Variable	Risk of sudden death	Poor (50% in 2 yrs)	Variable, high risk death

DCM = “DILATED = DEAD PUMP”

• Big heart

• Weak squeeze

• → Heart failure

HCM = “HUGE HEART = HARD TO FILL”

• Thick muscle

• Sudden death in athletes

• → Think syncope during exercise

RCM = “RESTRICTED FILLING”

• Normal squeeze

• Can’t fill

• → worst prognosis

ARVC = “ARRHYTHMIA + ATHLETE”

• Exercise-triggered

• Sudden death

• → ICD needed

Infective Endocarditis

• Infection + inflammation of the endocardium (inner heart lining) and valves

• Often occurs in children with:

  • Congenital heart disease (CHD)

  • Indwelling lines (e.g., PICC)

Infective Endocarditis - Causes

Most common organisms:

• Staphylococcus aureus

• Streptococcus viridans

Infective Endocarditis - Pathophysiology

1. Endothelial damage (CHD or catheter)

2. Platelets + fibrin deposit → clot forms

3. Bacteria enter bloodstream

4. Bacteria stick to clot → vegetation forms

5. Valve damage + infection spreads

Infective Endocarditis - Acute IE (FAST & SEVERE) CM

• High fever

• Toxic/very ill appearance

• Heart failure symptoms

• New or worsening murmur

Infective Endocarditis - Subacute IE (SLOW) CM

• Low-grade fever

• Fatigue

• Weight loss

• Malaise

• Joint pain

• Night sweats (diaphoresis)

Infective Endocarditis - Diagnostic Findings

• Positive blood cultures

• Echocardiogram:

  • Vegetations

  • Valve damage

Labs:

• ↑ ESR

• Leukocytosis

• Anemia

• Hematuria / proteinuria

Infective Endocarditis - Treatment

• V antibiotics for 4–6 weeks

  • Given via PICC line

• Based on culture sensitivity

Severe cases:

• Valve damage → surgery or valve replacement

Infective Endocarditis - Complications

• Heart valve destruction

• Heart failure

• Emboli → kidneys (renal damage)

• Chronic valve disease

Infective Endocarditis - Prophylaxis

Antibiotics BEFORE dental procedures if:

• Prosthetic heart valve

• Previous IE

• High-risk CHD:

  • Unrepaired cyanotic CHD

  • Recent repair (<6 months)

  • Residual defects

• Heart transplant with valve disease

Hypertension

• Elevated blood pressure based on:

  • Age

  • Gender

  • Height percentile

• Must be confirmed on 3 separate occasions

Hypertension - Risk Factors

• Overweight / abdominal obesity

• High salt intake

• Male sex

• Older age (adolescents)

• Family history

• Social determinants of health

Hypertension - Primary Hypertension

• Most common in older children/adolescents

• Causes:

  • Genetics

  • Lifestyle (diet, inactivity)

Hypertension - Secondary Hypertension

Caused by underlying condition:

• Renal disease (most common cause in kids)

• Cardiac disorders

• Pulmonary disorders

• Neurologic conditions

• Medications

Hypertension - Classification

Ages 1–13 years

• Normal: <90th percentile

• Prehypertension: 90th–<95th percentile

• Hypertension: ≥95th percentile

≥13 years (use adult values)

• Normal: <120/80

• Prehypertension: 120–129/<80

• Stage 1 HTN: 130–139 / 80–89

• Stage 2 HTN: ≥140/90

Hypertension - Assessment & Diagnosis

Proper BP Measurement

• Use correct cuff size:

  • Width = 40% of arm

  • Length = covers full circumference

• Measure in right arm

• Arm at heart level

• If high reading → repeat manually

Additional Evaluation

• History + family history

• Physical exam

• Possible tests:

  • Labs (renal function)

  • Imaging if secondary cause suspected

  • 24-hour ambulatory BP monitoring (more accurate)

Hypertension - Complications

• Early cardiovascular disease

• Left ventricular hypertrophy

• Early atherosclerosis

Hypertension - Management

First-line (LIFESTYLE CHANGES)

• Weight reduction

• Regular physical activity

• Healthy diet (↓ salt)

• Sleep hygiene

• Avoid smoking/alcohol

• Family-based interventions ↑ success

Hypertension - Medications

• ACE inhibitors

• ARBs

• Beta-blockers

• Calcium channel blockers

• Diuretics

• Vasodilators

👉 Monitor for side effects

Dyslipidemia

• Abnormal levels of:

  • Cholesterol

  • LDL (bad fat)

  • HDL (good fat)

  • Triglycerides

• Leads to early atherosclerosis → future cardiovascular disease

Dyslipidemia - Risk Factors

• Obesity

• Diabetes

• Hypertension

• Family history of early heart disease:

  • Male <55 years

  • Female <65 years

• Renal disease

• Some congenital heart diseases

• Why It Matters

  • Atherosclerosis begins in childhood

  • Risk factors in kids → adult heart disease

Dyslipidemia - Screening Guidelines

Universal Screening

• Ages 9–11

• Ages 17–21

Early Screening (Ages 2–8) if:

• Family history of dyslipidemia/early CVD

• Obesity (BMI >95th percentile)

• Diabetes or hypertension

Dyslipidemia - Diet Therapy

CHILD-1 Diet

• Low fat

• Low saturated fat

• Low cholesterol

→ If no improvement after 3 months:

CHILD-2 Diet

• More restrictive diet

Dyslipidemia - Medications

• Statins (if ≥10 years old)

Monitoring on Statins:

• Liver enzymes (hepatic transaminases)

• Creatine kinase (CK)

• Watch for muscle toxicity

Overweight & Obesity in Children

• Overweight: ≥85th percentile

• Obesity: ≥95th percentile

• ~1 in 3 children in the U.S. are overweight or obese

• Prevalence has:

  • Tripled (ages 2–5, 12–19)

  • Quadrupled (ages 6–11)

Obesity - Why It Matters

• Major risk factor for:

  • Cardiovascular Disease

  • Hypertension

  • Dyslipidemia

• Leads to lifelong complications:

  • Physical (diabetes, heart disease)

  • Psychological (low self-esteem, depression)

  • Social + economic impact

Obesity - Causes (Multifactorial)

• Poor diet (high fat, high sugar)

• Sedentary lifestyle

• Excess screen time

• Family habits

• Genetic predisposition

Obesity - Management (FIRST-LINE = Lifestyle)

Nutrition

• Low-fat diet

• Eliminate sugary drinks

• Reduce processed/sugary foods

Activity

• Increase daily physical activity

• Reduce sedentary behavior

Screen Time

• Limit TV, phones, gaming

Family-Based Approach

• Whole family must participate

• Improves long-term success