A 55-year-old male with a past medical history of hypertension, hyperlipidemia, and obesity presents to the outpatient internal medicine clinic with a 3-day history of fatigue and decreased exercise tolerance. He used to be able to walk 2 blocks without shortness of breath, but now he gets winded even walking in from the parking garage. He feels as though his heart is beating fast but denies palpitations. He has no chest pain, dizziness, visual changes, edema, or orthopnea. His medications include chlorthalidone, lovastatin, and aspirin.
On physical examination, his blood pressure is 120/60 mm Hg, pulse is 100 bpm, respiratory rate is 16/min, and pulse oximetry is 96% on room air. He is alert and answers questions appropriately. His lungs are clear to auscultation. His cardiac examination reveals an irregularly irregular rhythm that is tachycardic. Extremities reveal no edema. EKG is shown in Figure 10-1.
1. What is your diagnosis?
Atrial fibrillation, a form of supraventricular tachycardia (SVT).
A thorough clinical history and physical examination, as in any other case, are very important. Clinically significant tachyarrhythmias may produce symptoms of palpitations, lightheadedness, syncope, or dyspnea. Look for any triggering factors such as infection, inflammation, myocardial ischemia, drug toxicity, excess use of caffeine, tobacco, excessive alcohol intake, thyroid abnormalities, catecholamine excess, or electrolyte imbalances as potential causes.
A reasonable way to organize arrhythmias is into the following categories: supraventricular tachyarrhythmias, ventricular tachyarrhythmias, bradyarrhythmias, and conduction blocks.
- Quick recognition of arrhythmias is important and comes with practice and experience.
- Anticoagulation with warfarin has significant risks, so should be reserved for patients with high CHADS2 scores.
- Mortality outcomes are similar for patients with atrial fibrillation who are treated with rhythm control compared with those treated with rate control.
Ahya SN, Flood K, Paranjothi S. Cardiac Arrhythmias. The Washington Manual of Medical Therapeutics. 30th ed. Philadelphia: Lippincott Williams & Wilkins; 2001:153–167.
Cheng A, Kumar K. Overview of atrial fibrillation. In: Zimetbaum P, Saperia G, eds. UpToDate. 2012.
Phang R. Overview of the evaluation and management of atrial flutter. In: Zimetbaum P, Saperia G, eds. UpToDate. 2012.