The following correctable secondary causes of a<unk> <unk>  should be ruled out:
Hypercalcemia
Digoxin
Acidosis
Hyperkalemia
Short QT syndrome laboratory findings
Atrial fibrillation laboratory findings
Atrioventricular block laboratory findings
Right bundle branch block laboratory findings
Atrial flutter laboratory findings
AVNRT laboratory findings
Noonan syndrome ECG findings
Premature atrial contraction laboratory findings