Sensation of rapid or irregular heart rate
Cardiac disease
Known ECG abnormality
Syncope/pre-syncope
Exertional<unk> 
Hypotension or relative hypotension
Heart failure symptoms
Palpitations
Arrhythmias:
Chest pain 
Narrow-complex tachycardias
Heart murmurs
Wide-complex tachycardias
Hypopyon
AV blocks