What is a common ECG finding in digoxin toxicity?

In cases of digoxin toxicity, one of the hallmark ECG changes is the presence of ST depression and T wave inversion, particularly noted in the lateral leads such as V5 and V6. This specific pattern correlates with the effects of digoxin on the cardiac myocyte action potential. Digoxin increases intracellular calcium levels, which affects repolarization and can lead to these distinctive changes in the ST segment and the T wave on an ECG tracing.

The mechanism behind this involves the alteration of cardiac electrical activity due to digoxin’s role as a cardiac glycoside, which enhances the force of myocardial contractions but also affects the conduction system of the heart. Therefore, ST depression with accompanying T wave inversion is a significant indicator that could suggest digoxin toxicity in a patient.

The other options do not accurately reflect the typical ECG changes associated with digoxin toxicity. For instance, ST elevation is more suggestive of acute myocardial infarction rather than digoxin effects, flat T waves can have various causes unrelated to digoxin, and a prolonged QT interval primarily points towards other arrhythmia risks rather than digoxin specifically. Understanding these specific patterns is crucial in diagnosing and managing patients who may be experiencing digoxin toxicity.