1. Identify children with Kawasaki disease (KD) who are at high risk for life-threatening events.

2. Develop a management plan for patients with KD, based on current guidelines.

3. Describe indications for prophylaxis against development of infective endocarditis.

4. Recognize signs and symptoms of coronary artery anomalies in children and adolescents.

5. Evaluate patients for suspected middle airway obstruction.

Kawasaki Disease from a Cardiac Perspective
Mary B. Mehta, MD, Chair, Department of Pediatric Medicine, Nemours Children’s Clinic, Pensacola, FL

Epidemiology: worldwide, Kawasaki disease (KD) most common vasculitis in childhood; peak incidence at 12 mo of age (in 80% of cases, <5 yr of age)

Diagnostic criteria: fever >5 days (usually >102°F); plus ≥4 of the following—bilateral conjunctival injection; cervical adenitis; rash; inflamed oral mucosa (eg, strawberry tongue); inflammation on hands and feet (periungual peeling); caveat—fever plus 3 of 5 additional criteria diagnostic when coronary abnormalities present; bulbar injection—no exudate and area around pupil clear; supplemental criteria (American Heart Association [AHA])—albumin ≤3.0 g/dL; anemia; elevated alanine aminotransferase (ALT); platelet count ≥450,000/µL after 7 days; white blood cell count >15,000/µL; pyuria

KD in patients <1 yr of age: infants at high risk for coronary abnormalities (boys <6 mo of age at highest risk); incomplete KD—does not meet all criteria (presentation may be subtle)

Acute treatment: initiate treatment 5 to 10 days after onset; intravenous immune globulin (IVIG) 2 g/kg over 8 to 12 hr and aspirin 80 to 100 mg/kg per day until fever subsides; decrease aspirin dose for 6 to 8 wk, unless coronary involvement present; cardiac evaluation—echocardiography recommended in acute phase and at 6 to 8 wk posttreatment

Cardiac complications: early—myocarditis; peripheral ischemia (especially at <1 yr of age); pericardial effusion; 14 days to 3 mo—coronary artery (CA) aneurysm with or without thrombosis; late—coronary stenosis or thrombosis with ischemia; valvar leak; red flags—age ≤1 yr (especially boys ≤6 mo of age); prolonged recurrent fevers; early cardiac dysfunction; thrombocytopenia; anemia; hypoalbuminemia

Monitoring children and adolescents with heart disease who are receiving stimulant medications

Background: ≤50% incidence of attention-deficit/hyperactivity disorder (ADHD) in children with heart disease; from 1999 to 2003—25 people (19 children) died suddenly while taking medication for ADHD, and 43 people (19 children) had cardiovascular events; from 1992 to 2005—11 sudden deaths with methylphenidate reported, and 13 sudden deaths with amphetamines; in 2007—Food and Drug Administration (FDA) directed drug manufacturers to notify patients of these episodes

Causes of sudden cardiac death: hypertrophic cardiomyopathy; long QT syndrome; cardiomyopathy; arrhythmogenic right ventricular (RV) dysplasia

Prevention of sudden cardiac death: techniques—screening by electrocardiography (ECG); defibrillator use; ECG screening in athletes successful in Europe; AHA recommendations (2007)—for any patient receiving stimulant medications for ADHD, obtain personal history, family history, and ECG reading by pediatric cardiologist; clarification (American Academy of Pediatrics [AAP] and AHA, 2008)—obtain class I evidence (personal history, family history, physical examination [PE]); class II evidence (ECG reasonable, not mandatory); do not withhold medical therapy pending ECG results

Prophylaxis for Subacute Bacterial Endocarditis: New Guidelines
Dr. Mehta

Principles driving 1997 AHA guidelines: infective endocarditis (IE; also known as bacterial endocarditis) uncommon but can be life-threatening; certain conditions (eg, congenital heart disease) predispose patients to IE; prevention better than treatment; IE caused by bacteremia caused by infective organisms which are introduced by procedures; prophylaxis proven effective in laboratory (animal studies); subacute bacterial endocarditis prophylaxis (SBEP) “seems to work” in humans; validity of the following assertion questioned—“antimicrobial prophylaxis is effective in humans for prevention of infectious endocarditis associated with dental, gastrointestinal (GI), or genitourinary (GU) procedures”

Reasons for AHA 2007 revisions: bacteremia more common with daily activities than with dental procedures; prophylaxis prevented few cases of IE; risk for adverse events from antibiotic use; good oral hygiene more likely to prevent bacteremia; rationale for SBEP—Streptococcus viridans and enterococci susceptible to antibiotics; dental procedures can cause bacteremia; case reports of dental procedures causing IE; antibiotic reactions rarely fatal; IE associated with high morbidity and mortality

Risk factors for bacteremia: dental procedures—tooth extraction (accounts for 10%-100% of cases of bacteremia related to dental procedures); teeth cleaning; endodontic procedures; periodontal surgery; daily activities—brushing teeth; toothpicks; water pics; chewing food; AHA—emphasis on oral hygiene more likely to improve outcomes than antibiotic prophylaxis

Cardiac risk factors for IE: highest risks—cardiac valve replaced for native-valve IE; previous IE; cardiac valve replaced for infected prosthetic valve

Indications for SBEP (AHA)

Overview: prophylaxis recommended for cardiac conditions associated with highest risk for adverse outcome from IE, and in which procedures thought to be related

Cardiac risk factors: unrepaired cyanotic heart disease with shunts or conduits; repair of congenital heart defect (using prosthetic material) within last 6 mo; repaired congenital heart defect, with residual defect at site of prosthetic material; development of cardiac valvopathy after cardiac transplantation; caveats—SBEP not indicated for other types of congenital heart disease; >6 mo after surgery, SBEP not indicated if no evidence of residual defects present

Patients with cardiac risk factors: SBEP recommended for dental procedures involving gingiva, perforate mucosa, or periapical region of tooth; administer single dose before procedure (if missed, administer within 2 hr)

Patients with GU or GI conditions: in most procedures, SBEP not recommended (no studies support prophylaxis); treat infection with appropriate antibiotics before procedure; enterococcal coverage important

Medical history: if patient already on antibiotic used for SBEP, add second; if infection present, delay procedure and treat infection if possible

Summary: antibiotic prophylaxis recommended for all dental procedures involving manipulation of gingival tissue or periapical region of teeth (but not for routine anesthesia, dental x-rays, or orthodontic procedures) in patients who have underlying cardiac conditions associated with highest risk for adverse outcomes from IE

Coronary Artery Anomalies
William J. Ravekes, MD, Assistant Professor of Pediatrics, Division of Pediatric Cardiology, Johns Hopkins University School of Medicine, and Staff Member, the Helen B. Taussig Children’s Heart Center, Baltimore, MD

Case 1: 10-yr-old boy collapsed while playing basketball; avid athlete; resuscitated on site, with ongoing cardiac arrest; extracorporeal membrane oxygenation (ECMO) administered upon arrival at pediatric intensive care unit; initially, troponin I markedly elevated; no family history; severe heart dysfunction detected on transthoracic echocardiography; transesophageal echocardiography revealed aberrant origin of left coronary artery (LCA) from right coronary sinus of Valsalva; hospital course—serial physical examinations (PEs) and echocardiography showed no improvement; patient put on list for transplantation and sent to cardiac catheterization laboratory to stent anomalous LCA (no improvement in ventricular function); patient developed large subdural hematoma and herniation on ECMO; life support withdrawn

Case 2: 8-yr-old brother of boy in case 1; history of small atrial septal defect (ASD); also athlete; parents requested screening; on PE, short early systolic murmur (alone, not significant); on echocardiography, right coronary artery (RCA) arising from left sinus; slit-like orifice to RCA; left coronary system normal; small ASD; cardiac computed tomography (CT) confirmed RCA course

Causes of sudden death in young athletes: hypertrophic cardiomyopathy; CA abnormalities; other

Natural history: <50% of survivors of acute event had preceding symptoms (most commonly, previous syncopal event or chest pain [especially with activity]); often, no symptoms preceding cardiac arrest or sudden death; phenotype rarely develops before puberty (average age at time of death 16 yr); RCA from left sinus more likely to have no preceding symptoms

Pathology of CA anomalies: slit-like lumen and kinking of CA; flap-like closure of coronary os; intramural course; CA compressed between aorta and main pulmonary artery (theoretic) repeated ischemic events

Clinical evaluation: symptoms—chest pain, syncope, or near-syncope during exercise (especially during exercise [not during recovery]); patients frequently asymptomatic; family history—other case reports of familial clustering of CAs; PE—typically normal; 12-lead ECG not diagnostic (normal ECG does not rule out problem); stress ECG (yield only ≈30%); diagnostic imaging—in experienced hands, proximal LCA and RCA seen on transthoracic echocardiography in ≈95% of young athletes; if echocardiography equivocal, consider other imaging studies

Treatment: restriction from sports and vigorous activities; surgical repair—no medical therapy for anomalous CA; excellent short- and mid-term results

Case 2 revisited: because of high risk for sudden death, patient underwent unroofing procedure; now doing well with normal exercise capacity

Summary: anomalous CA rare, but mortality rate high; consider possibility of diagnosis in patients with exertional chest pain, fatigue, or syncope during physical activity; benign PE and ECG do not exclude diagnosis (refer to pediatric cardiologist); if CA anomaly suspected, perform echocardiography and other imaging studies as necessary; screen first-degree relatives; patient with anomalous CA at increased risk for sudden death during exercise; surgical treatment associated with excellent outcomes

Middle Airway Obstruction
Michael Light, MD, Professor of Clinical Pediatrics, University of Miami Miller School of Medicine, Miami, FL

Stridor

Characteristics: harsh vibratory sound of variable pitch; supraglottic obstruction—produces inspiratory stridor (usually high-pitched); extrathoracic tracheal obstruction—includes glottis and subglottis; may cause biphasic stridor (sound heard on inspiration and expiration); usually intermediate pitch; intrathoracic tracheal obstruction—causes expiratory or biphasic stridor; stertor—snoring sound

Evaluation (Rudman, 2003): comparison of direct laryngoscopy and bronchoscopy with nasopharyngoscopy, airway fluoroscopy, and plain films; conclusion—airway fluoroscopy quick noninvasive dynamic study of entire airway; with airway fluoroscopy, sensitivity 80% for detecting subglottic obstruction (73% for tracheal, 80% for bronchial sites); less sensitive for supraglottic and glottic obstruction (33% and 14%, respectively; nasopharyngoscopy most useful technique for defining pathology at those sites)

Congenital hemangioma: subglottic hemangioma most common soft tissue mass obstructing upper airway; infants present with stridor and cough within few weeks after birth; ≈50% of tracheal hemangiomas associated with cutaneous hemangiomas; infantile hemangiomas tend to regress spontaneously

Subglottic stenosis (SGS): congenital or acquired narrowing of subglottic airway (located at cricoid cartilage); subglottic airway narrowest part; can affect glottis, subglottis, and trachea; signs include scarring or fibrosis; endotracheal intubation in newborn period most common cause of laryngotracheal stenosis; other causes include blunt trauma to neck, high tracheotomy, cricothyrotomy, extrinsic compression of airway, and gastroesophageal reflux

Recurrent respiratory papillomatosis: uncommon but potentially life-threatening benign tumor of respiratory tract; tends to recur; caused by human papillomavirus (types 6 and 11; symptoms include dyspnea, cough, and stridor; best treatment CO2 laser excision; interferon not helpful

Tracheomalacia: if lesion extrathoracic, collapse and airway sounds occur primarily during inspiration (if intrathoracic, during expiration); because most of trachea intrathoracic, most affected children have asthma rather than croup phenotype

Tracheobronchomalacia (TBM): symptoms include stridor (inspiratory, expiratory, or biphasic); barking cough (croup phenotype), and wheeze (asthma phenotype); paradoxic response to β-adrenergics not uncommon (makes obstruction worse); more severe problems include anoxic spells and cyanosis; recurrent pulmonary infections not uncommon; etiologies of primary TBM—prematurity; congenital anomalies of cartilage; Ehlers-Danlos syndrome; mucopolysaccharidosis; tracheoesophageal (TE) fistula; etiologies of secondary TBM—prolonged intubation; tracheostomy; compression from vascular ring; scoliosis; pectus excavatum; tumors and cysts (especially bronchogenic; rare in children); lymphoma

Tracheal stenosis: single tracheal ring, multiple rings, or entire length of trachea involved; symptoms (which include dyspnea, biphasic stridor, and prolonged expiration) may be present at birth or delayed for several months; associated with vascular slings, TE fistulae, pulmonary hyperplasia, and trisomy 21

Bacterial tracheitis: signs and symptoms—onset follows croup or viral upper respiratory infection; in second week of illness, patients present with high fever and toxic appearance; tracheal secretions copious and purulent; diagnosis confirmed by endotracheal intubation; pathogens—atypically staphylococcal; other organisms include Pseudomonas and anaerobes; treatment—use of smaller endotracheal tube; often, frequent suctioning needed

Bronchogenic cyst: possibly life-threatening in infants and young children (particularly when right mainstem bronchus compressed); management controversial and varies; malignant transformation main concern; if asymptomatic, leave cyst in place; Takeda 1999 —all patients <1 yr of age had respiratory distress but no episodes of infection; patients >1 yr of age tended to have infection without respiratory distress

Foreign body aspiration: >10,000 emergency department visits/yr related to children ≤14 yr of age choking on food; hot dogs most common (followed by hard candy, peanuts, other nuts, and seeds); when lodged in middle airway, foreign body can produce stridor and significant respiratory distress; special circumstances—coins normally stay in esophagus but may erode through it