A 62-Year-Old Woman Is Complaining of Palpitations and Feeling Dizzy

A 62-year-old woman is complaining of palpitations and feeling dizzy. She said this happened yesterday, and she sat down and it went away. She has a history of hypertension and is taking irbesartan (an angiotensin receptor blocker) . Her vital signs are as follows: temperature, 98.8 ºF; pulse irregular, 110 beats per minute; respiratory rate, 20 per minute; and blood pressure, 110/70 mm/Hg. An electrocardiogram will likely reveal:

A) ventricular tachycardia.
B) sinus tachycardia.
C) atrial fibrillation.
D) second-degree atrioventricular block.