An antiarrhythmic drug used to treat bradycardia inadvertently creates tachycardia.The most likely reason is that this drug causes _____ of the ______.

Question

Quizplus · Accepted Answer

An antiarrhythmic drug used to treat bradycardia would be expected to inhibit the heart rate by decreasing the rate of firing of the sinoatrial (SA) node. Therefore, if the drug inadvertently causes tachycardia, it suggests that the drug is stimulating the SA node instead of inhibiting it. Choice B correctly identifies this mechanism of action. The other options (A, C, D, and E) either do not involve the SA node or do not provide an explanation for why the drug would cause tachycardia.

An Antiarrhythmic Drug Used to Treat Bradycardia Inadvertently Creates Tachycardia