In non-rheumatic atrial fibrillation, true is?
**Core Concept**
Atrial fibrillation (AF) is a common cardiac arrhythmia characterized by rapid and irregular heart rhythms, originating from the atria. In non-rheumatic AF, the underlying cause is not related to rheumatic heart disease, which is a major risk factor for AF in developing countries.
**Why the Correct Answer is Right**
The correct answer is related to the pathophysiology of AF, which involves abnormal electrical activity in the atria. In non-rheumatic AF, the increased risk of stroke is primarily due to the formation of blood clots in the left atrium, which can then embolize to the brain. This is because the irregular heart rhythm leads to stasis of blood in the atria, allowing clot formation to occur. The correct answer is related to the management of non-rheumatic AF, which typically involves anticoagulation therapy to prevent stroke.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because anticoagulation therapy is not the primary treatment for non-rheumatic AF, although it may be used in certain cases. The primary treatment for AF involves rate or rhythm control using medications or cardioversion.
**Option B:** This option is incorrect because the risk of myocardial infarction (MI) in non-rheumatic AF is not directly related to the arrhythmia itself, but rather to underlying cardiovascular disease.
**Option C:** This option is incorrect because the primary risk factor for stroke in non-rheumatic AF is not left ventricular dysfunction, but rather the formation of blood clots in the left atrium.
**Option D:** This option is incorrect because the primary treatment for non-rheumatic AF does not involve the use of beta blockers.
**Clinical Pearl / High-Yield Fact**
Anticoagulation therapy with warfarin or novel oral anticoagulants (NOACs) is recommended for patients with non-rheumatic AF who have a high risk of stroke, typically defined as a CHA2DS2-VASc score of 2 or greater.
**Correct Answer:** C.