The following Potassium channel opener is used in angina
**Core Concept**
The question is testing the student's knowledge of potassium channel openers, which are a class of drugs used to treat angina by increasing potassium efflux from cardiac cells, leading to a decrease in the action potential duration and a subsequent reduction in myocardial oxygen demand.
**Why the Correct Answer is Right**
The potassium channel opener used in angina is pinacidil. It works by opening ATP-sensitive potassium channels (K ATP channels) in the cardiac cell membrane. This leads to an increase in potassium efflux, which shortens the action potential duration and reduces the contractility of the heart. This reduction in contractility decreases the myocardial oxygen demand, thus alleviating angina symptoms.
**Why Each Wrong Option is Incorrect**
* **Option A:** is incorrect because it is not a potassium channel opener used in angina.
* **Option B:** is incorrect because it is actually a potassium channel blocker, which would have the opposite effect of increasing myocardial oxygen demand.
* **Option C:** is incorrect because it is a beta-blocker, which decreases heart rate and contractility through a different mechanism.
**Clinical Pearl / High-Yield Fact**
Potassium channel openers are a class of drugs that can be used to treat angina by reducing myocardial oxygen demand. They work by increasing potassium efflux from cardiac cells, leading to a decrease in action potential duration and contractility.
**Correct Answer:** C.