Phenylalkylamines and benzothiazepines toxicity may result in sinus bradycardias, varying degrees of atrioventricular block, bundle branch block, junctional rhythms and prolonged QT.
Dihydropyridines toxicity can result in a reflex sinus tachycardia.
Blood glucose
Hyperglycaemia is a marker of severity of toxicity
Arterial blood gas
May show a metabolic acidosis and hyperlactatemia
U&Es
Creatinine may be raised due to impaired end organ perfusion