Low Voltage

Definition

• less than 5mm on all limb leads QRS complex amplitude, or
  
• less than 10mm on all precordial leads
  or
• QRS amplitude I + II + III = less than 15mm
  or V1 + V2 + V3 = less than 30 mm
  

Differentials:

1. constrictive pericarditis
2. Large pericardial effusion
3. infitrative myocardial disease
4. End-stage CMP
5. prior massive MI
   
   
6. Myxedema
7. severe obesity
   
   
8. large pleural effusion
9. severe COPD
   
   
   
   
   
   
   (source: ECG for Emergency Physician -- Mattu and Brady)