As every medical resident knows who is studying for their board exam, the six common causes of wide QRS on electrocardiogram (ECG) are:
1. ventricular tachycardia
2. supraventricular tachycardia with aberrancy
3. drug-induced intraventricular conduction delay
4. right and left bundle branch block
5. pacemaker driven QRS
6. Wolff Parkinson White Syndrome
What about Myotonic Muscular Dystrophy?