- See: V Tach 
- More than 6 per min, 3 in a row, or R on T is pathological; 
-Note if they are from the same focus; 
- P waves may be present be will have no relation to QRS wave of PVC; 
- QRS is usually > 0.12 seconds w/ Left bundle branch pattern; 
- look for compensatory pause following PVC; 
- Bigeminy: one normal sinus beat alternating w/ one PVC; 
- Trigeminy: two normal beats followed by one PVC; 
- Unifocal:: arises from one site in the ventricle; 
- Multifocal PVCs: arise from different sites, & have different shapes; 
- increased risk for V. fib; 
- PVC on T wave: 
- increased risk for V. fib; 
- PVCs ordinarily occur just after T wave of a normal cycle; 
Causes of PVCs: 
1) Ischemia: Angina/MI 
2) Valvular Heart Disease/Mitral Valve Prolapse; 
3) HTN 
4) Medication Toxicity: 
- Digitalis 
- Aminophylline
- Epinephrine 
- isoproterenol  
5) Hypokalemia: 
6 Hypomagnesemia 
7) Hypoxia 
8) Met. Acidosis 
9) Cardiomyopathy  
10) Mitral Valve Prolaspe; 
11) Meds: Digoxin 
12) Hyperthyroidism 
13) Caffeine 
14) Anxiety 
15) Anemia, 
16) Normal Varient