Final answer:
In a patient with atrial fibrillation lasting more than 48 hours, direct current (DC) or chemical cardioversion to sinus rhythm is not recommended due to the risk of complications, particularly the formation of blood clots. Anticoagulant medications are often prescribed to minimize these risks.
Step-by-step explanation:
Direct current (DC) or chemical cardioversion to sinus rhythm is not recommended in a patient with atrial fibrillation lasting more than 48 hours because it carries an increased risk of complications, particularly the formation of blood clots. Atrial fibrillation can cause blood to pool in the heart, increasing the risk of clot formation. When the heart is reset to a normal sinus rhythm through DC or chemical cardioversion, there is a risk that these formed clots can be dislodged and travel to other parts of the body, causing a stroke or other serious complications.
In such cases, it is recommended to prescribe anticoagulant medications before attempting to restore sinus rhythm to minimize the risk of clot formation and potential complications.