Atrial fibrillation laboratory tests

Overview
While many cases of AF have no definite cause, it may be the result of various other problems (Blood tests of thyroid function are required, especially for a first episode of AF, when the ventricular rate is difficult to control, or when AF recurs unexpectedly after cardioversion)

Hence, renal function and electrolytes are routinely determined, as well as thyroid-stimulating hormone (commonly suppressed in hyperthyroidism and of relevance if amiodarone is administered for treatment) and a blood count.

In acute-onset AF associated with chest pain, cardiac troponins or other markers of damage to the heart muscle may be ordered. Coagulation studies (INR/aPTT) are usually performed, as anticoagulant medication may be commenced.