who needs cardiac monitoring, and for how long?

almost certainly need cardiac monitoring

condition	duration
possible cardiac chest pain	until 2nd trop is normal unless high risk features mandate further monitoring
hyperkalaemia	until K+ < 6.5
acute pulmonary oedema
acute coronary syndrome	24hrs from onset of pain and then reassess
STEMI or non-STE-ACS
life threatening arrhythmias:	24hrs from onset
post cardiac arrest
VF / V flutter
asystole
VT
accessory pathway (eg. WPW) with rapid vent. response tachycardias
syncope or tachycardia or bradycardia with haemodynamic compromise possibly due to primary cardiac condition	excl. vasovagal, hypovolaemia, etc
temporary cardiac pacing
Mobitz II or 3rd degree AV blocks
Long QTc syndrome with ventricular arryhythmia
new RAF in pts with certain heart diseases (eg. HOCM) where new onset AF may be lethal
pharmacologic
IV cardiac drug Rx such as inotropes, vasoactive drugs, type I/III antiarrhythmic agents (amiodarone, sotalol, quinidine, procainamide, lignocaine, phenytoin, flecainide, propafenone)
overdose of substance with potential pro-arrhythmic effects (eg. VT, prolonged QTc) as per toxicologist or cardiologist

condition	duration
delayed presentation NSTEMI	cease once troponins negative or after 24hrs whichever is earlier
post-op patients at high risk of ischaemia
AF with rapid ventricular response	until HR < 120
syncope with no obvious cause, especially in the elderly or with either: LBBB; RBBB+fasc. block; QRS >= 0.12sec; Mobitz I; HR < 50; sinus pause > 3sec; pre-excited QRS complexes; Brugada syndrome; Q waves suggesting AMI; possible arrhythmogenic RV dysplasia (neg. T waves R precordial leads, epsilon waves, ventricular late potentials); vent. dysplasia	excl. vasovagal, postural, micturition, carotid sinus syncope, POTS, autonomic failure, hypovolaemic
significant risk of resp. or cardiac arrest

pericarditis
large perocardial effusion
suspected cardiac blunt trauma
stable patients with PVCs
very high voltage electrocution
electrocution with abnormal ECG or cardiac symptoms
chronic AF with haemodynamic compromise

chronic AF on iv digoxin loading

chronic AF without haemodynamic compromise

asymptomatic 1st degree heart block

patients with a stable, functioning ICD or PPM which has been checked

raised troponin due to non-coronary ischaemia (although these patients may need ICU/HDU for undelying issue)

household voltage or lower voltage electrocution / electrical injury with normal ECG and no cardiac symptoms