text: Lown and Graboys proposed the grading system for premature<unk><unk>  which is used for prognostic purposes.
option_0: Premature ventricular contraction EKG examples
option_1: Intraventricular conduction delay EKG examples
option_2: Paroxysmal AV Block EKG examples
option_3: Atrial fibrillation EKG examples
option_4: Junctional bradycardia EKG examples
option_5: Wide complex tachycardia laboratory findings
option_6: Premature atrial contraction laboratory findings
option_7: Right bundle branch block laboratory findings