Which condition can digitalis toxicity lead to?

Digitalis toxicity can lead to a variety of cardiac arrhythmias, and one notable effect is paroxysmal atrial tachycardia with a 2:1 block. This is primarily due to the effects of digoxin on the atrial tissues, which can increase automaticity and lead to such a rhythm.

In digitalis toxicity, the increased vagal tone and the enhancement of atrial ectopic activity can result in a situation where the atria may fire rapidly but only every other impulse is conducted to the ventricles, hence the term “2:1 block.” This phenomenon is often observed in patients already predisposed to atrial dysrhythmias, such as those with underlying heart disease or electrolyte imbalances.

This unique arrhythmia occurs due to the dual actions of digitalis: it enhances parasympathetic tone while also promoting depolarization in cardiac tissues. Recognizing paroxysmal atrial tachycardia with a 2:1 block as a manifestation of digitalis toxicity allows for timely intervention to restore a normal rhythm and manage the toxicity effectively.