Lown and Graboys proposed the grading system for premature<unk><unk>  which is used for prognostic purposes.
Premature ventricular contraction EKG examples
Intraventricular conduction delay EKG examples
Paroxysmal AV Block EKG examples
Atrial fibrillation EKG examples
Junctional bradycardia EKG examples
Wide complex tachycardia laboratory findings
Premature atrial contraction laboratory findings
Right bundle branch block laboratory findings