3-lead and 5-lead ECG monitoring are bedside cardiac monitoring systems used mainly in hospitals (ICU, ED, CCU, telemetry) to continuously observe heart rhythm—not for full diagnostic ECGs like a 12-lead. 

3-Lead ECG Monitoring 

Purpose: Basic rhythm monitoring 

Leads & Placement 
RA (Right Arm): below right clavicle 
LA (Left Arm): below left clavicle 
LL (Left Lower): left lower chest


What it shows 
One bipolar lead at a time (Lead I, II, or III) 
Most commonly Lead II for rhythm observation 

Uses 
Heart rate monitoring 
Detecting arrhythmias (AF, VT, bradycardia, tachycardia) 

Limitations 
No reliable ST-segment analysis 
Limited view of cardiac electrical activity 

 
5-Lead ECG Monitoring 

Purpose: Rhythm monitoring plus ischaemia/ST monitoring 

Leads & Placement 
(Mnemonic: Ride Your Green Bike Well (Red, Yellow, Green, Black, White))
RA: right clavicle area 
LA: left clavicle area 
RL: right lower chest (ground) 
LL: left lower chest 
V (Chest lead): usually V1 or V5 

What it shows 
Limb leads (I, II, III, aVR, aVL, aVF) 
One precordial (chest) lead 

Uses 
Continuous rhythm monitoring 

ST-segment monitoring 
Better detection of ischemia and ventricular arrhythmias 

Advantages over 3-lead 
More accurate rhythm interpretation 
Early detection of myocardial ischemia 
 
Quick Comparison