II. Definition
- Sudden unexpected nocturnal death
- Includes only idiopathic cases of Sudden Cardiac Death
III. Epidemiology
-
Incidence: Uncommon
- Accounts for <5% of Sudden Cardiac Death cases
- Family History of sudden death events often present
- Most common in men
- Greater Incidence in Southeast asia
- Northeastern Thailand (40/year per 100,000)
- Japan
- Philipines
IV. Pathophysiology
- J Wave Syndrome
- Inherited disorder of myocardial Sodium channels
- No structural abnormalities
V. Symptoms
- Often asymptomatic until terminal event (40%)
- Exertional Syncope history may be present
- Agonal Respirations may be present during sleep
VI. Diagnostics: EKG findings
- Prolonged QT Interval
- Right Bundle Branch Block
- Brugada Sign
- Seen best in the right precordial leads (V1-V3)
- End of QRS marked by significant upward deflection (J Point Elevation)
- ST Segment Elevation (leads v1-v3)
- Types
- Type 1 (coved-type, wide and large J Wave)
- Type 2 (saddleback pattern)
- J-Wave amplitude >2 mm (or mV) at peak AND
- ST Elevation >1 mm above baseline, gradually down-sloping AND
- Positive or biphasic T Wave
- Type 3
- Right precordial ST Elevation
VII. Diagnosis
- Shanghai Scoring System
VIII. Labs
- Genetic Test is available
IX. Management
- Symptomatic, type I Brugada morphology is most concerning
- Treatment Options
- Management decisions are based on symptomatic versus asymptomatic Brugada findings
- Internal Cardiac Defibrillator (ICD)
- Quinidine
-
Exercise and sports participation are not contraindicated
- However avoid significant Hypothermia or hyperthermia
- Avoid provocative factors
X. Complications
- Ventricular Tachycardia
- Cardiac Arrest with Ventricular Fibrillation
-
Sudden Cardiac Death
- Mean age of onset 41 years old (but range of onset varies from newborns to elderly)
XI. Prognosis
- Mortality: 10% (without ICD placement)
XII. References
- Krishnan (2018) Cardiac Arrhythmias Conference, UMN, Minneapolis, MN
- Joshi and Dermark (2016) Crit Dec Emerg Med 30(8):3-12
- Antzelevitch (2003) J Am Coll Cardiol 41(10):1665-71 [PubMed]
- Brugada (1992) J Am Coll Cardiol 20(6):1391-6 [PubMed]
- Littmann (2003) Am Heart J 145(5):768-78 [PubMed]
- Meyer (2003) Am Fam Physician 68(3):483-8 [PubMed]