A 65-year-old man comes to the emergency department because of a 2-hour history of palpitations and lightheadedness. He has no chest pain or dyspnea. He has had 3 episodes of symptomatic atrial fibrillation that self-terminated within last week. He has hypertension treated with lisinopril. He is 183 cm (6 ft 0 in) tall and weighs 100 kg (220 lb); BMI is 30 kg/m2. Temperature is 37.0°C (98.6°F), pulse is 150/min, and blood pressure is 130/85 mm Hg. Cardiac examination demonstrates tachycardia with irregularly irregular heartbeats. ECG confirms atrial fibrillation. The patient's ventricular rate is controlled with beta blocker therapy, but the arrhythmia fails to resolve as in previous episodes. Which of the following factors is most likely involved in the progression of this patient's arrhythmia?

Question

A 65-year-old man comes to the emergency department because of a 2-hour history of palpitations and lightheadedness. He has no chest pain or dyspnea. He has had 3 episodes of symptomatic atrial fibrillation that self-terminated within last week. He has hypertension treated with lisinopril. He is 183 cm (6 ft 0 in) tall and weighs 100 kg (220 lb); BMI is 30 kg/m2. Temperature is 37.0°C (98.6°F), pulse is 150/min, and blood pressure is 130/85 mm Hg. Cardiac examination demonstrates tachycardia with irregularly irregular heartbeats.  ECG confirms atrial fibrillation.  The patient's ventricular rate is controlled with beta blocker therapy, but the arrhythmia fails to resolve as in previous episodes.  Which of the following factors is most likely involved in the progression of this patient's arrhythmia?

Quizplus · Accepted Answer

Eductional Objective: Atrial remodeling is the major pathogenic contributor to atrial fibrillation.  Age and comorbidities that cause atrial dilation (eg, hypertension, heart failure, mitral valve disease) cause atrial structural changes that predispose to atrial fibrillation development.  In addition, age and previous atrial fibrillation cause atrial conduction system changes that further propagate atrial fibrillation.

A 65-Year-Old Man Comes to the Emergency Department Because of a 2-Hour