What are heart conditions in kids?

Heart Conditions in Children: A Comprehensive Overview

Heart conditions in children encompass both congenital heart disease (present at birth) and acquired cardiac conditions, with congenital heart disease being the most common form affecting approximately 1.3% of U.S. children currently and representing a leading cause of morbidity and mortality in the pediatric population. 1, 2

Categories of Pediatric Heart Disease

Congenital Heart Disease (CHD)

Congenital heart disease represents structural abnormalities of the heart present from birth and is the most prevalent form of heart disease in children. 3, 4

• Simple lesions include conditions like patent ductus arteriosus (PDA), atrial septal defects, and ventricular septal defects 5, 6
• Complex lesions involve single-ventricle physiology, transposition of the great arteries, and tetralogy of Fallot requiring staged surgical palliation 1, 4
• Left-sided obstructive lesions such as aortic stenosis and coarctation of the aorta carry increased risk of sudden cardiac death 1

Acquired Heart Conditions

Acquired heart disease develops after birth and includes several distinct categories with varying mortality risks. 1, 6

• Cardiomyopathies (hypertrophic, dilated, restrictive) represent a leading indication for heart transplantation in children 1, 7
• Kawasaki disease can cause coronary artery aneurysms and represents a Tier I (high-risk) condition when current aneurysms are present 1
• Myocarditis presents with acute inflammation of the heart muscle and can progress to fulminant heart failure 1, 6
• Infective endocarditis occurs with bacterial or fungal infection of heart valves or endocardium, presenting indolently with fever and constitutional symptoms 1
• Arrhythmias including supraventricular tachycardia, long-QT syndrome, and ventricular arrhythmias can cause sudden cardiac death 1, 8

Life-Threatening Conditions with Sudden Death Risk

Several pediatric heart conditions can present with sudden cardiac death as the initial manifestation, making early detection critical for mortality reduction. 1

High-Risk Conditions

• Hypertrophic cardiomyopathy is the most common cause of sudden cardiac death in young athletes 1
• Coronary artery anomalies cause sudden death during vigorous exercise 1
• Long-QT syndrome predisposes to lethal ventricular arrhythmias 1
• Commotio cordis results from blunt chest trauma causing ventricular fibrillation, with 5-10 cases reported annually nationwide 1

The estimated risk of sudden cardiac arrest in high school athletes is 0.5 to 1.0 per 100,000 athletes per year, representing 25-50 episodes nationwide annually. 1

Clinical Presentations by Age Group

Infants

Infants with heart disease present with feeding difficulties, failure to thrive, tachypnea, diaphoresis with feeding, and signs of congestive heart failure. 7, 3

• Critical congenital heart disease may present in the first days to weeks of life with cyanosis or cardiovascular collapse as the ductus arteriosus closes 1, 5
• Supraventricular tachycardia in infants requires medical treatment due to difficulty recognizing symptoms and risk of heart failure 8
• Modified Ross Class II (mild heart failure) manifests as mild tachypnea or diaphoresis with feeding 7
• Modified Ross Class III (moderate heart failure) shows marked tachypnea, prolonged feeding times, and growth failure 7

School-Age Children and Adolescents

Older children may be asymptomatic until catastrophic events occur, or present with exercise intolerance, chest pain, palpitations, or syncope. 1, 3

• Syncope during tachycardia indicates severe fall in cardiac output from extremely rapid heart rate and represents a life-threatening presentation 8
• Dyspnea on exertion progressing from moderate (Class II) to minimal exertion (Class III) indicates worsening heart failure 7
• Indolent presentations with prolonged low-grade fever, fatigue, weakness, and weight loss suggest infective endocarditis 1

Cardiovascular Risk Stratification

The American Heart Association has established a three-tier risk stratification system for pediatric populations with accelerated atherosclerosis risk. 1

Tier I (High Risk) - Manifest coronary artery disease before age 30

• Homozygous familial hypercholesterolemia 1
• Type 1 diabetes mellitus 1
• Chronic kidney disease/end-stage renal disease 1
• Post-heart transplantation 1
• Kawasaki disease with current coronary aneurysms 1

Tier II (Moderate Risk) - Accelerated atherosclerosis with pathophysiological evidence

• Heterozygous familial hypercholesterolemia 1
• Kawasaki disease with regressed coronary aneurysms 1
• Type 2 diabetes mellitus 1
• Chronic inflammatory disease 1

Tier III (At Risk) - High-risk setting with epidemiological evidence

• Post-cancer treatment survivors 1
• Congenital heart disease 1
• Kawasaki disease without detected coronary involvement 1

Heart Failure in Children

Heart failure in pediatric patients with congenital heart disease represents a major contributor to ongoing morbidity and mortality, with staging adapted from adult ACC/AHA guidelines. 7, 4

Staging System

• Stage A (At Risk): No symptoms, structural disease, or biomarkers but at risk for heart failure 7
• Stage B (Pre-HF): No symptoms but evidence of structural heart disease, increased filling pressures, or elevated cardiac biomarkers 7
• Stage C (Symptomatic HF): Structural heart disease with current or previous heart failure symptoms 7
• Stage D (Advanced HF): Symptoms interfering with daily life and recurrent hospitalizations despite optimal medical therapy 7

Clinical Assessment

Assessment must include respiratory symptoms (tachypnea, retractions), cardiovascular signs (sinus tachycardia, hepatomegaly), feeding difficulties, and evaluation of biomarkers (BNP, NT-proBNP) with echocardiographic parameters. 7

Special Populations Requiring Intensive Management

Single-Ventricle Physiology

Children with single-ventricle physiology require specialized post-operative management with attention to balancing systemic and pulmonary blood flow. 1, 9

• After stage 2 palliation (superior cavopulmonary anastomosis), mild hypoventilation with hypercarbia improves systemic perfusion by increasing cerebral blood flow and venous return 1
• After Fontan completion, hypoventilation and acidosis must be avoided as they increase pulmonary vascular resistance and decrease cardiac output 1
• Stroke risk is 2.4 per 1000 patient-years with antithrombotic treatment versus 13.4 per 1000 patient-years without treatment 1

Pulmonary Hypertension

Pulmonary hypertension is present in up to 2% of postoperative patients and increases cardiac arrest risk, with pulmonary hypertensive crises triggered by pain, anxiety, suctioning, hypoxia, and acidosis. 1, 9

• Children with VSD, pulmonary atresia, and ductal stenting are at particularly high risk for pulmonary hypertensive crises 9
• Crisis management requires increased FiO2, ventilatory support, acidosis correction, and consideration of inhaled nitric oxide 9

Healthcare Utilization and Special Needs

Sixty percent of children with current heart conditions have one or more special health care needs, representing a 3.1-fold increased prevalence compared to children without heart conditions. 2

• Functional limitations are 6.3 times more common in children with current heart conditions (30.7%) versus those without (4.6%) 2
• Males, children with lower family income, and those in non-two-parent households have increased prevalence of special health care needs among those with heart conditions 2
• Approximately 900,000 U.S. children currently have heart conditions, with an additional 755,000 having past heart conditions 2

Critical Pitfalls in Management

Many screening programs for pediatric heart disease fail to consider needed infrastructure, staffing costs, and impact of false-positive or false-negative results. 1

• Routine ECG or echocardiography screening is not recommended for mass screening of young athletes, with emphasis instead on risk assessment questionnaires and physical examination 1
• Oral hygiene and prevention of oral disease should receive disproportionately greater focus than antibiotic prophylaxis for dental procedures, as prophylaxis efficacy remains unproven 1
• Many cardiac conditions are not detected during routine school physicals or sports screenings, making sudden cardiac arrest the first presentation 1
• Extracardiac manifestations of infective endocarditis (petechiae, Roth spots, Janeway lesions, Osler nodes) are considerably less common in children than adults 1

Stroke Risk and Prevention

Twenty-three percent of children with ischemic stroke have cardiac disorders, with stroke considered secondary to illness or procedures in 82% of cases. 1

• Surgical procedures account for 40% of stroke events, with catheterization (5%), ECMO (5%), and cardiac arrest (8%) representing additional risks 1
• Prothrombotic abnormalities including elevated lipoprotein(a), anticardiolipin antibodies, and protein C deficiency increase stroke risk in children with heart disease 1
• Stroke recurrence risk is 2.7% at median 44-month follow-up, with greater risk in children having one or more prothrombotic factors 1

Transplantation Considerations

Heart transplantation is indicated for children with end-stage heart disease refractory to maximal medical therapy when no surgical procedure can restore productive life. 1

• Cardiomyopathy and complex congenital heart disease without myocardial failure represent the two main diagnoses leading to transplantation 1
• Pediatric transplantation comprises 10% of all heart transplantations performed annually, with numbers continuing to increase 1
• Pretransplantation noncompliance history is highly associated with post-transplantation noncompliance, representing the major cause of late graft loss 1