What condition is characterized by a “scooped out” ST segment on an ECG?

The presence of a “scooped out” ST segment on an ECG is most characteristic of digoxin toxicity. In this condition, the digitalis effect, which is seen with medications that are derived from the foxglove plant (digoxin being the most common), alters the repolarization phase of the cardiac cycle. The scooped appearance is due to changes in the action potential of myocardial cells that result from the effects of digoxin on the sodium-potassium ATPase pump.

Digoxin increases intracellular calcium concentration, which enhances myocardial contractility, but it also leads to characteristic ECG findings including the scooped ST segment and sometimes other changes in the T wave. Recognizing this specific alteration can be critical for clinicians, as it helps distinguish digoxin toxicity from other cardiac conditions that may also present with ST segment changes.

In contrast, conditions like acute myocardial infarction, ventricular hypertrophy, and myocardial ischemia exhibit different patterns on an ECG such as ST segment elevation or depression, T wave inversion, or modification of the QRS complex but do not typically create the distinct “scooped out” appearance associated with digoxin toxicity. Understanding these unique ECG patterns assists in proper diagnosis and treatment of various cardiovascular conditions.