Syncope
Dysrhythmias
PVCs (most common)
Bradycardia
SVT with AV block
Junctional escape
Increased Automaticity: atrial tachycardia, regularized atrial fibrillation
Ventricular dysrhythmias, including bidirectional V-tach (esp in chronic toxicity)
Bidirectional vtach is pathognomonic for<unk> 
Digitalis Effect (seen with therapeutic levels; not indicative of toxicity)
T wave changes (flattening or inversion)
QT interval shortening
Scooped ST segments with depression in lateral leads
Increased U-wave amplitude
PVCs (most common)
Bradycardia
SVT with AV block
Junctional escape
Increased Automaticity: atrial tachycardia, regularized atrial fibrillation
Ventricular dysrhythmias, including bidirectional V-tach (esp in chronic toxicity)
Bidirectional vtach is pathognomonic for<unk> 
Bidirectional vtach is pathognomonic for<unk> 
T wave changes (flattening or inversion)
QT interval shortening
Scooped ST segments with depression in lateral leads
Increased U-wave amplitude
Often the earliest manifestation of toxicity
Nausea/vomiting
Abdominal Pain
Nausea/vomiting
Abdominal Pain
Confusion
Weakness
Visual disturbances
Yellow halos
Scotomas
Delirium
Yellow halos
Scotomas
Hyperkalemia (acute poisoning)
Hypokalemia
Hypomagnesemia
Worsens toxicity
Worsens toxicity
Digoxin toxicity
Cardiac
Beta-blocker toxicity
Inferior MI 
Amiodarone pulmonary toxicity
Sick sinus syndrome
Clonidine toxicity
Neurocardiogenic/reflex-mediated