What kind of arrhythmia is generally associated with digitalis toxicity?

What kind of arrhythmia is generally associated with digitalis toxicity?

• A. Atrial fibrillation
• B. Paroxysmal atrial tachycardia (PAT)
• C. Supraventricular tachycardia (SVT)
• D. Premature ventricular contractions

Answer: (B)

Paroxysmal atrial tachycardia (PAT) is a type of arrhythmia that is specifically associated with digitalis toxicity. When digitalis is taken, it can enhance vagal tone, leading to increased automaticity in the atria, which can trigger episodes of PAT. This results in a rapid heart rate due to the reentry circuits or triggered activity within the atria.

Digitalis works by slowing down conduction through the atrioventricular (AV) node and can also increase the contractility of the heart muscle by inhibiting the sodium-potassium ATPase pump. However, its effects on the atrial circuitry are what predispose an individual to develop PAT during periods of digitalis toxicity.

Understanding the specific mechanisms of how digitalis interacts with cardiac tissue helps clarify why PAT is the most likely arrhythmia to observe in cases of overdose or toxicity. This knowledge is crucial for identifying potential risks in patients taking digitalis and for managing their treatment effectively.