<unk>  is a sudden collapse into unconsciousness due to a disorder of heart rhythm causing heart blocks in which there is a slow or absent pulse resulting in decreased blood flow to the brain causing syncope (fainting) with or without convulsions. High grade arrhythmias often lead to abrupt decrease in cardiac output and transient loss of consciousness.
Adams-Stokes syndrome
COACH syndrome
Jerusalem syndrome
DRESS syndrome
MOMO syndrome
Decompression sickness
IMAGE syndrome
Hennekam syndrome