1. Sudden Cardiac Death in Children & Young Adults
Rebecca A. Steinmann, RN, APN, MS, CEN, CCRN, CCNS
Clinical Educator, Emergency Department
Children’s Memorial Hospital, Chicago, Il

2. Sudden Cardiac Death
Abrupt, unexpected death due to cardiac causes in a person with known or unknown cardiac disease in whom no previously diagnosed fatal conditions is apparent
75% of deaths are due to an abnormal heart rhythm
VT/VF

3. Background
young people die suddenly and unexpectedly from cardiac dysrhythmias/month
Average age of collapse: 17 years of age
Most die from congenital/hereditary structural or functional cardiovascular abnormalities

4. Causes of SCD in the Young

5. Sudden Cardiac Death Anatomic Substrate Trigger Electrical instability
Underlying structural/functional abnormality
Trigger
Transient  in blood flow to the heart
Systemic factors
 BP,  O2, electrolyte imbalances
Altered levels of hormones and chemical transmitters
Toxic effects of drugs
Electrical instability

6. Objectives Identify four common causes of
sudden cardiac arrest in children and
young adults.
Discuss the identification and
management of patient’s with
hypertrophic cardiomyopathy.
Describe the identification and
management of patient’s with Long QT
Syndrome.

7. Hypertrophic Cardiomyopathy
Epidemiology
Affects % of population
Most common cause of SCD in athletes
Most common cause of SCD in individuals < 30 years of age
Symptoms commonly present during 2nd decade of life
> 50% of cases inherited
Autosomal dominant genetic disorder

8. Hypertrophic Cardiomyopathy
Epidemiology
Incidence of SCD
4-6%/year in children and adolescents
2-4%/year in adults
Most episodes of SCD occur at rest or with mild exertion
Progressive disorder that worsens over time

9. Hypertrophic Cardiomyopathy
Pathophysiology
Disorganization of muscle fibers  LV hypertrophy
Most commonly the septum just below the aortic valve  outflow tract obstruction

10. Hypertrophic Cardiomyopathy
Pathophysiology
LV stiff  impaired filling
Mitral valve dysfunction
Mitral regurgitation
Cardiac ischemia and malignant arrhythmias
VF (80% of cases)

11. Hypertrophic Cardiomyopathy
Presentation
Most patients are asymptomatic until a cardiac event occurs
SCD
Syncope/pre-syncope (15-25%)
Dizziness*
Angina*
Palpitations
Dyspnea* (90% of cases)
Systolic murmur

12. Hypertrophic Cardiomyopathy
Diagnosis
ECG
LV hypertrophy, ST-T wave abnormalities
CXR: cardiomegaly

13. Hypertrophic Cardiomyopathy
Diagnosis
2-Dimensional echocardiogram

14. Hypertrophic Cardiomyopathy
Patient Management
Medications
Beta-blockers
Calcium Channel blockers
Antidysrhythmics: Amiodarone
Pacemaker
ICD

15. Hypertrophic Cardiomyopathy
Patient Management
Septal ablation (ethanol ablation)
Creates small septal AMI
Left ventricular myomectomy

16. Hypertrophic Cardiomyopathy
Patient Management
Family CPR
Evaluation of first-degree relatives
Avoid inotropes, nitrates, strenuous activity

17. Coronary Artery Anomalies
2nd leading cause of SCD in young athletes
Accounts for % of all congenital heart defects
85% of cases present with
signs of CHF within
1-2 months of age
90% mortality in 1st
year of life

18. Coronary Artery Anomalies
Pathophysiology
Results from an embryologic “glitch” in which the LCA arises from an abnormal origin
Pulmonary artery, coronary sinuses

19. Coronary Artery Anomalies
Pathophysiology
Left ventricle is perfused with desaturated blood
Myocardial ischemia with activity
Anterolateral infarct in neonate VF
Collateral circulation may develop between right & left coronary artery

20. Coronary Artery Anomalies
Presentation
Neonate/infant
Poor feeding
 heart rate
 respiratory rate
Failure to thrive
Older children/young adults often asymptomatic
Vigorous exercise myocardial ischemia  VF  SCD

21. Coronary Artery Anomalies
Diagnosis
ECG: Anterolateral infarct/ischemia

22. Coronary Artery Anomalies
Diagnosis
2-Dimensional echocardiogram with Doppler color flow mapping
TEE
MRI
Angiography

23. Coronary Artery Anomalies
Management
Surgical revascularization to a 2 coronary artery system

24. Ion Channelopathies
Long QT syndrome
Brugada syndrome

25. Long QT Syndrome
Disorder characterized by prolongation of the QT interval  VT (torsades)

26. Long QT Syndrome Congenital Acquired long QT:
Occurs in 1:3,000-5,000 individuals
Males have a higher rate of cardiac events
Leading cause of SCD in young females
Linked to 5% of SIDS cases
Acquired long QT:
Scarring
Medications

27. Long QT Syndrome Pathophysiology Mutations in cardiac ion channels
Overload of positively charged ions in the myocardial cells during repolarization
Prolonged recovery from excitation increases the likelihood of a premature beat initiating a reentry rhythm
VT (torsades de pointes)  VF

28. Long QT Syndrome Diagnosis/Presentation Symptomatic (60%)
Syncope  adrenergic arousal
Intense emotions (42%)
Vigorous physical exercise (41%)
Awakening (19%)
Swimming (15%)
Auditory stimuli (8%)
Seizures
Palpitations

29. Long QT Syndrome Diagnosis/Presentation Asymptomatic (40%)
Usually diagnosed after a cardiac event has occurred
Syncope
Sudden Cardiac Death

30. Long QT Syndrome Diagnosis: 12 Lead ECG
QTc > 0.46 seconds in child < 15 years
QTc > 0.45 seconds in adult male
QTc > 0.46 seconds in adult female
T wave alternans
QTc = __QT__
√RR

31. Long QT Syndrome

32. Long QT Syndrome Patient Management: Beta-blockers
High thoracic left sympathectomy
Implanted cardiac defibrillator

33. Long QT Syndrome Patient Management:
Avoidance of QT prolonging drugs (
Anesthetics
Asthma medications
Antihistamines
Antibiotics
Antidysrhythmics
Antipsychotics
Catecholamines
Avoiding hypokalemia

34. Long QT Syndrome Patient Management: CPR
Family education:
CPR
Testing of first-degree relatives

35. Brugada Syndrome Congenital genetic mutation
Occurs in 5:10,000 individuals
Autosomal dominant transmission
Endemic in Southeast Asia
2nd leading cause of death in males < 40 years of age with structurally normal hearts
VF/SCD usually occurs at night or rest

36. Brugada Syndrome Dysfunction of sodium ion channels
Polymorphic VT  VF
Supraventricular arrhythmias in 20% of cases
Lethal dysrhythmias associated with
Febrile illness
Hypokalemia
Myocardial ischemia
Bradycardia

37. Brugada Syndrome
Usually diagnosed after an aborted SCD event or syncope
Characteristic ECG findings
Coved ST segment elevation in V1-V3 followed by negative
T wave

38. Brugada Syndrome Patient Management: Pacer/ICD
Pharmacologic agents have proven
largely ineffectual
Quinidine?
Avoidance of medications that induce Brugada-like ECG patterns
Family CPR

39. Commotio cordis Epidemiology
Occurs most commonly in males < 20 years
Majority < 12 years of age
Why are children more vulnerable?
Narrow chest cage
Undeveloped chest wall muscles
Greater compliance of chest wall

40. Commotio cordis Epidemiology
62% of events occurred at organized sporting events
Baseball
Ice hockey
Football
50% suffer immediate collapse
84% fatalities

41. Commotio cordis Pathophysiology
Impact directly over the heart during the peak of the T wave  VF

42. Commotio cordis
Presentation
Sudden collapse after impact to the chest

43. Commotio cordis Patient Management
Outcome directly related to length of time to defibrillation
AED

44. Commotio cordis-type presentation
Tasers??

45. Aortic Rupture Epidemiology Congenital abnormality of
the connective tissues
Marfan’s syndrome
Vascular Ehlers-Danlos
Syndrome (ED IV)

46. Aortic Rupture Pathophysiology Collagen defect in walls of vessels
Mechanical stress dilatation of the wall of the aorta  rupture
Valves may also be affected

47. Aortic Rupture: Marfan’s Syndrome
Physical findings:
Characteristic physical findings
Long lanky frame
Hypermobile joints
Funnel chest
Scoliosis
Thin narrow face
Small lower jaw
Hypotonia
Near-sightedness

48. Aortic Rupture: Vascular Ehlers-Danlos Syndrome (EDS IV)
Physical findings
Thin, transparent skin
Prominent venous patterns on chest and abdomen
Easy bruising
Only 16% diagnosed before presentation with vascular complication

49. Aortic Rupture Diagnosis: CXR Echocardiogram Genetic testing
Fibrilin-1 mutation (Marfan’s)

50. Aortic Rupture Patient Management Beta-blockers
Minimize dilatation of the aortic root
Yearly evaluation of aortic root by echocardiogram
Surgical repair of dilated aorta

51. Miscellaneous causes of SCD
Wolff-Parkinson-White Syndrome
Incidence: 0.1% of population
Embryonic “glitch”
Risk of SCD 0-4%
Accessory AV pathway that permits rapid heart rates
Reentry tachycardia
A. Fib/flutter (11-38%)

52. Miscellaneous causes of SCD
Wolff-Parkinson-White Syndrome

53. Miscellaneous Causes of SCD
Wolff-Parkinson-White Syndrome
Palpitations most common sign
Heart rates in the range of 250 are common
A Fib/flutter may degenerate to VF

54. Miscellaneous Causes of SCD
Wolff-Parkinson-White Syndrome
Characteristic 12 Lead ECG
Short PR, widened QRS, delta wave

55. Miscellaneous Causes of SCD
Wolff-Parkinson-White Syndrome
Management:
Stable: Amiodarone, Procainamide, Over-drive pacing
Unstable: Cardioversion
Long-term:
Medication therapy to control
rate
Radiofrequency ablation
of accessory pathway

56. Miscellaneous Causes of SCD
Arrythmogenic RV dysplasia
Progressive cardiomyopathy characterized by partial replacement of the RV myocardium with fibrous/fatty tissue
Patchy distribution

57. Miscellaneous Causes of SCD
Arrythmogenic RV dysplasia
Incidence 1:5,000 persons
Risk of SCD 2%/year
30-50% of cases familial disorder
Autosomal-dominant inheritance
Viral??

58. Miscellaneous Causes of SCD
Arrythmogenic RV dysplasia
Characteristics
Thinning and enlargement of the RV wall
Poor RV contractility

59. Miscellaneous Causes of SCD
Arrythmogenic RV dysplasia
Characteristics
Sustained monomorphic or polymorphic VT with LBBB morphology  VF

60. Miscellaneous Causes of SCD
Arrythmogenic RV dysplasia
Presentation:
Palpitations
Syncope
SCD
Congestive heart failure

61. Miscellaneous Causes of SCD
Arrythmogenic RV dysplasia
Diagnosis:
ECG
Epsilon wave V1-V3
Widening of QRS in V1-V3
T wave inversion in anterior leads
2-D echocardiogram
MRI

62. Miscellaneous Causes of SCD
Arrythmogenic RV dysplasia
Patient Management:
Antiarrythmic agents
ICD
Catheter ablation
Ventriculostomy
Management of CHF

63. Miscellaneous Causes of SCD
Coronary Artery Disease
Kawasaki disease
Leading cause of acquired heart disease in children < 5 years of age (U.S.)
An acute, self-limiting, multisystem disorder characterized by microvascular inflammation
Unknown etiology
Thought to be infectious or autoimmune

64. Miscellaneous Causes of SCD
Coronary Artery Disease
Kawasaki disease
15-25% of untreated patients develop cardiovascular sequelae
Coronary artery aneurysms  thrombosis, MI, sudden death
Risk of SCD highest 4-8 weeks after onset of symptoms

65. Miscellaneous Causes of SCD
Coronary Artery Disease
Kawasaki disease
Fever > 38.5 C. (101.3  F.)
for 5 or more days 5 days +
4 of the 5 following clinical signs:
Changes in extremities
Edema, erythema, generalized desquamation

66. Miscellaneous Causes of SCD
Coronary Artery Disease
Kawasaki disease
Bilateral conjunctivitis
Not associated with exudates
Polymorphous rash

67. Miscellaneous Causes of SCD
Coronary Artery Disease
Kawasaki disease
Changes in lips and oral cavity
Cervical lymphadenopathy with one node > 1.5 cm

68. Miscellaneous Causes of SCD
Coronary Artery Disease
Kawasaki disease
Supportive care (fluids, antipyretics)
Anti-inflammatory therapy
Aspirin:  inflammation, lowers fever, prevents blood clots
Intravenous immune gamma globulin (IVIG)
Treatment within first 10 days of illness reduces rate of cardiac sequelae from 20-25% to 2-4%

69. Miscellaneous Causes of SCD
Coronary Artery Disease
Acute Coronary Syndrome
High-risk:
Hemoglobinopathies: Sickle cell anemia
Leukemia/cancer survivors
Congenital heart disease/repairs
Familial history of hyperlipidemia
Smokers
Obesity
Hypertension
Diabetics

70. Miscellaneous Causes of SCD
Coronary Artery Disease
Acute Coronary Syndrome
Occlusion of coronary artery  myocardial ischemia  development of ventricular dysrhythmias
Diagnosis: ECG, cardiac enzymes
Management:
“MONA”
Adjunctive medications
Reperfusion strategies

71. Warning Signs Exertional syncope Near-syncope, dizziness
Excessive, unexpected, unexplained dyspnea or fatigue associated with exercise
Exertional chest pain/discomfort
Past detection of heart murmur with  systolic BP
Family history of premature death
< 40 years

72. Screening Complete and careful personal and family history
Physical exam
Precordial auscultation
Lying and standing
Assessment of femoral pulses
Brachial BP

73. Discussion/Questions