Cardiovascular-mediated syncope
Dysrhythmias:
WPW (pre-excitation)
Long<unk>  Syndrome/QT<unk> 
Brugada Syndrome
Catecholaminergic polymorphic ventricular tachycardia
2nd/3rd AV Block
Afib/aflutter
Vtach/torsades
Sick sinus syndrome
Arrhythmogenic right ventricular dysplasia
Short<unk>  syndrome
Cardiovascular disease
Valvular Disease (AS, MS, tricuspid stenosis)
Aortic Dissection
Myocardial Infarction
CHF
Hypertrophic Cardiomyopathy
PE
Pericardial Tamponade
Myxoma
Pulmonary Hypertension
Pacemaker malfunction
Neurally mediated syncope
Vasovagal:
Fear, pain, emotion, valsalva, breath-holding spell
Situational (associated with):
Coughing, micturition, defecation, vomiting, swallowing, postexercise
Carotid sinus stimulation
Orthostatic hypotension-mediated syncope:
Volume depletion:
Dehydration (vomiting, diarrhea)
Hemorrhage, (Ectopic Pregnancy, Upper GI Bleed/Lower GI Bleeding, Abdominal Aortic Aneurysm)
Sepsis
Autonomic Dysreflexia
Autonomic failure due to meds
Other serious causes
Stroke
SAH
TIA
Vertebrobasilar Insufficiency
Subclavian steal
Heat syncope
Hypoglycemia
Hyperventilation
Asphyxiation
Seizure
Narcolepsy
Psychogenic (anxiety, conversion disorder, somatic symptom disorder)
Toxic (drugs, carbon monoxide, etc.)
Dysrhythmias:
WPW (pre-excitation)
Long<unk>  Syndrome/QT<unk> 
Brugada Syndrome
Catecholaminergic polymorphic ventricular tachycardia
2nd/3rd AV Block
Afib/aflutter
Vtach/torsades
Sick sinus syndrome
Arrhythmogenic right ventricular dysplasia
Short<unk>  syndrome
Cardiovascular disease
Valvular Disease (AS, MS, tricuspid stenosis)
Aortic Dissection
Myocardial Infarction
CHF
Hypertrophic Cardiomyopathy
PE
Pericardial Tamponade
Myxoma
Pulmonary Hypertension
Pacemaker malfunction
WPW (pre-excitation)
Long<unk>  Syndrome/QT<unk> 
Brugada Syndrome
Catecholaminergic polymorphic ventricular tachycardia
2nd/3rd AV Block
Afib/aflutter
Vtach/torsades
Sick sinus syndrome
Arrhythmogenic right ventricular dysplasia
Short<unk>  syndrome
Valvular Disease (AS, MS, tricuspid stenosis)
Aortic Dissection
Myocardial Infarction
CHF
Hypertrophic Cardiomyopathy
PE
Pericardial Tamponade
Myxoma
Pulmonary Hypertension
Pacemaker malfunction
Vasovagal:
Fear, pain, emotion, valsalva, breath-holding spell
Situational (associated with):
Coughing, micturition, defecation, vomiting, swallowing, postexercise
Carotid sinus stimulation
Fear, pain, emotion, valsalva, breath-holding spell
Coughing, micturition, defecation, vomiting, swallowing, postexercise
Carotid sinus stimulation
Volume depletion:
Dehydration (vomiting, diarrhea)
Hemorrhage, (Ectopic Pregnancy, Upper GI Bleed/Lower GI Bleeding, Abdominal Aortic Aneurysm)
Sepsis
Autonomic Dysreflexia
Autonomic failure due to meds
Dehydration (vomiting, diarrhea)
Hemorrhage, (Ectopic Pregnancy, Upper GI Bleed/Lower GI Bleeding, Abdominal Aortic Aneurysm)
Sepsis
Stroke
SAH
TIA
Vertebrobasilar Insufficiency
Subclavian steal
Heat syncope
Hypoglycemia
Hyperventilation
Asphyxiation
Seizure
Narcolepsy
Psychogenic (anxiety, conversion disorder, somatic symptom disorder)
Toxic (drugs, carbon monoxide, etc.)
QT prolongation
Cardiovascular-mediated syncope
T wave changes
Dysrhythmias:
ST segment elevation
WPW 
ST segment depression
Long QT Syndrome/QT prolongation