Report:

Atrial fibrillation

VEBs, bigeminal, multiform

Nonspecific ST/T changes

Comment:

Multiform bigeminy is quite characteristic of digoxin toxicity. The VEBs are relatively narrow and may be of fascicular origin. The last 6 beats are all ventricular; the last 5 alternate in polarity and would, at a faster rate, constitute bidirectional VT – a rare entity with much greater specificity for digoxin toxicity than mere bigeminy.

As often happens, the supraventricular beats that precede the VEBs are ‘regularised’ by the latter, despite AF.

The patient had rising creatinine (90 to 101 mmol/L) and digoxin (1.6 to 2.2 nmol/L) levels as well as falling potassium ( 3.8 to 3.3 mEq/L) level before this trace was obtained; there is little doubt that she was toxic even though the last recorded digoxin level was within the therapeutic range [1.0 – 2.6 nmol/L]. An echocardiogram showed dilated left atrium, with moderate mitral incompetence and normal left ventricular systolic function.

One of her previous traces is shown below (Fig 185a).