Milrinone-Induced Bidirectional Ventricular Tachycardia

Report:

Atrial fibrillation with rapid response

VEBs, some in dimorphic couplets

Four-beat run of bidirectional ventricular tachycardia 126/min

Comment:

The VT obviously consists of two dimorphic couplets in a row; its significance in the absence of digoxin therapy (i.e., toxicity) is unknown. For 48 hours, AF and frequent VEBs such as shown here were accepted because of the improvement in cardiac output with milrinone. Oddly enough, there was no progression to sustained or hypotensive VT; the ventricular response to AF (and perhaps VT as well) was controlled by amiodarone. If required, milrinone-related ventricular ectopic activity could have been controlled by beta-blockers95.

This patient had a very large infarction, true cardiogenic shock and eventually died in multiple organ failure. His ECG (Fig 107a) showed infarction through loss of R waves and ST depression only. Unlike anterior ones, inferior infarcts do not seem to indicate their size through electrocardiography.

A previous episode of VT is shown in Fig 107b. The inferior infarct pattern is clearly discernible.