A healthy 24-year-old male presents with a sore throat of 2 days’ duration. He reports mild congestion and a dry cough. On examination, his temperature is 37.2°C (99.0°F). His pharynx is red without exudates, and there are no anterior cervical nodes. His tympanic membranes are normal, and his chest is clear.
Which one of the following would you do?
Correct Answer A:
The Centers for Disease Control and Prevention (CDC) assembled a panel of national health experts to develop evidence based guidelines for evaluating and treating adults with acute respiratory disease. In clinical screening, the most reliable predictors of streptococcal pharyngitis are the Centor criteria. These include tonsillar exudates, tender anterior cervical lymphadenopathy, absence of cough, and history of fever.
Patients with four positive criteria should be treated with antibiotics, those with three positive criteria should be tested and treated if positive, and those with 0-1 positive criteria should be treated with analgesics and supportive care only. This patient has only one of the Centor criteria, and according to the panel should not be tested or treated with antibiotics.
For long-term therapy, the most effective control of heart rate in atrial fibrillation, both at rest and with exercise, occurs with which one of the following?
Correct Answer B:
For long-term therapy, beta-adrenergic antagonist drugs provide the most effective control of heart rate in atrial fibrillation, both at rest and during exercise. Although calcium channel blockers also lower heart rate both at rest and with exercise, they are not as effective as Beta-blockers. Digitalis is primarily effective in controlling the heart rate at rest, and often does not adequately control heart rate with exercise. The Class 1 antiarrhythmics are most useful in maintaining sinus rhythm and, in fact, may paradoxically increase heart rate.
Which one of the following diseases is most commonly associated with atrial fibrillation?
Correct Answer D:
Atrial fibrillation can be a cardiac sequela of primary noncardiac diseases. Systemic hypertension is present in 45% of patients with atrial fibrillation. Atrial fibrillation is also associated with diabetes mellitus, pulmonary diseases (specifically COPD, primary pulmonary hypertension, and acute pulmonary embolism), and acute ethanol ingestion. Atrial fibrillation is not commonly associated with Crohn's disease, tuberculosis, hypothyroidism (2% of patients), or rheumatoid arthritis.
Compared to patients with permanent atrial fibrillation, patients with paroxysmal atrial fibrillation have a risk of stroke that is:
Correct Answer E: Patients with paroxysmal atrial fibrillation (i.e., self-terminating) and persisting atrial fibrillation (i.e., that lasts more than 7 days or requires cardioversion) appear to have a risk of stroke that is similar to that of patients with permanent atrial fibrillation.
A 77-year-old male presents to your clinic in atrial fibrillation with a rate of 132 beats/min. He has hypertension, but no history of heart failure or structural heart disease. He is otherwise healthy and active.
The best initial approach to his atrial fibrillation would be:
Correct Answer E:
Regardless of the long-term management strategy chosen, control of ventricular rate is a critical component of management of new-onset atrial fibrillation (AF). Rate-controlling agents act primarily by increasing AV nodal refractoriness.
Beta-blockers and calcium channel blockers are first-line agents for rate control in AF. They are effective at rest and with exertion. Intravenous diltiazem or metoprolol are commonly used for AF with a rapid ventricular response. Caution should be exercised in patients with reactive airway disease who are given beta-blockers.
→ Digoxin can be used in the acute setting but does little to control the ventricular rate in active patients. As such, it is rarely used as monotherapy. Digoxin is indicated in patients with heart failure and reduced LV function.
→ Amiodarone is recommended for use as a rate-controlling agent for patients who are intolerant of or unresponsive to other agents, such as patients with CHF who may otherwise not tolerate diltiazem or metoprolol.
Several risk factor assessment algorithms have been developed to aid the clinician on decisions on anticoagulation for patients with AF. The CHADS2 index (Cardiac failure, Diabetes, Stroke [or S2 = transient ischemic attack]) is the most widely used of these algorithms. The CHADS2 index uses a point system to determine yearly thromboembolic risk. Two points are assigned for a history of stroke or transient ischemic attack (TIA), and one point is given for age older than 75 years or a history of hypertension, diabetes, or heart failure. This patient's CHADS2 score is 2 and therefore, anticoagulation therapy should be initiated.
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