A 73-year-old man is brought to the emergency department after repeat episodes of lightheadedness. Yesterday, the patient felt lightheaded while jogging and sat down on the curb to prevent a fall. A similar episode occurred 6 weeks ago when he felt lightheaded while climbing stairs. He has had some exertional shortness of breath associated with chest discomfort for the past few months but has had no headache, blurry vision, or chest pain. Medical history includes hypertension. The patient takes hydrochlorothiazide and low-dose aspirin daily. He has a 20-pack-year history and occasionally drinks a glass of wine. Blood pressure is 142/90 mm Hg, pulse is 80/min, and respirations are 16/min. ECG shows normal sinus rhythm with left ventricular hypertrophy. Which of the following is most likely to diagnose this patient's condition?

Question

A 73-year-old man is brought to the emergency department after repeat episodes of lightheadedness.  Yesterday, the patient felt lightheaded while jogging and sat down on the curb to prevent a fall.  A similar episode occurred 6 weeks ago when he felt lightheaded while climbing stairs.  He has had some exertional shortness of breath associated with chest discomfort for the past few months but has had no headache, blurry vision, or chest pain.  Medical history includes hypertension.  The patient takes hydrochlorothiazide and low-dose aspirin daily.  He has a 20-pack-year history and occasionally drinks a glass of wine.  Blood pressure is 142/90 mm Hg, pulse is 80/min, and respirations are 16/min.  ECG shows normal sinus rhythm with left ventricular hypertrophy.  Which of the following is most likely to diagnose this patient's condition?

Quizplus · Accepted Answer

Explanation: 11ec25c8_d2d7_af02_bc81_490aa79c8af5_MD0003_00 This patient's clinical presentation is most suggestive of severe aortic stenosis (AS). Patients with AS are usually asymptomatic for a prolonged period, with classic symptoms typically occurring only after progression to severe AS (valve area usually <1 cm²). Classic symptoms of severe AS include the following: ² Exercise intolerance and exertional dyspnea: Severe valvular stenosis obstructs left ventricular outflow, preventing an increase in cardiac output during exercise. Exertional angina: Left ventricular hypertrophy (as seen on this patient's ECG) compensates for the increased afterload caused by the stenosed aortic valve. On exertion, oxygen delivery is inadequate (due to inability to appropriately increase cardiac output) to supply the increased oxygen requirements of the hypertrophied myocardium, resulting in angina. Presyncope (ie, lightheadness) or syncope: Cerebral perfusion pressure decreases during exercise because cardiac output cannot increase sufficiently to offset the decrease in systemic vascular resistance that occurs with exercise-induced peripheral vasodilation. Transthoracic echocardiography should be obtained in all patients with suspected AS to confirm the diagnosis, assess the severity of AS, and evaluate left ventricular size and function. Failure to treat severe AS can lead to irreversible heart failure and sudden death. Definitive treatment is surgical valve replacement. (Choice A) 24-hour ECG monitoring can detect paroxysmal arrhythmias (eg, ventricular tachycardia, atrial fibrillation with rapid ventricular response) that may cause presyncope. However, the consistent association of this patient's symptoms with exertion and left ventricular hypertrophy on ECG are more suggestive of AS than of intermittent arrhythmias. (Choice B) Carotid stenosis (which can be evaluated with carotid ultrasound) can lead to decreased cerebral perfusion, which rarely presents with lightheadedness on exertion. However, it would not explain this patient's exertional dyspnea and chest discomfort. (Choice D) Upright tilt table testing may be used to diagnose orthostatic or vasovagal syncope in patients with recurrent unexplained syncope. However, other more dangerous causes (eg, structural heart disease) of presyncope/syncope should be ruled out first. (Choice E) Exercise stress testing is considered when exertional symptoms (eg, angina, dyspnea) occur in the setting of known or suspected coronary artery disease. However, severe, symptomatic AS is a contraindication for exercise stress testing due to the risk of complications, including syncope and death; therefore, echocardiography should be performed first when severe AS is suspected. Educational objective: Symptoms of severe aortic stenosis include exercise intolerance, exertional dyspnea and angina, and exertional presyncope/syncope. Echocardiography should be obtained in all patients with suspected structural heart disease (eg, aortic stenosis). References: Evaluation of syncope. (http://www.ncbi.nlm.nih.gov/pubmed/16273816) Diagnostic patterns and temporal trends in the evaluation of adult patients hospitalized with syncope. (http://www.ncbi.nlm.nih.gov/pubmed/11493131)

A 73-Year-Old Man Is Brought to the Emergency Department After