A 67-year-old man comes to the emergency department due to progressive shortness of breath and chest tightness. He has had no lightheadedness or syncope. The patient takes lisinopril for hypertension and metformin for type 2 diabetes mellitus. He has smoked a pack of cigarettes daily for the last 40 years. The blood pressure cuff is inflated to 140 mm Hg and the pressure is released very slowly. At 120 mm Hg, intermittent Korotkoff sounds are heard only during expiration. At 100 mm Hg, Korotkoff sounds are heard throughout the respiratory cycle. This physical examination finding can be seen in which of the following conditions?

Question

A 67-year-old man comes to the emergency department due to progressive shortness of breath and chest tightness.  He has had no lightheadedness or syncope.  The patient takes lisinopril for hypertension and metformin for type 2 diabetes mellitus.  He has smoked a pack of cigarettes daily for the last 40 years.  The blood pressure cuff is inflated to 140 mm Hg and the pressure is released very slowly.  At 120 mm Hg, intermittent Korotkoff sounds are heard only during expiration.  At 100 mm Hg, Korotkoff sounds are heard throughout the respiratory cycle. This physical examination finding can be seen in which of the following conditions?

Quizplus · Accepted Answer

Systemic arterial pressure normally falls by <10 mm Hg during normal inspiration. Pulsus paradoxus refers to an exaggerated drop (>10 mm Hg) in systolic blood pressure during inspiration. It is detected by inflating a blood pressure cuff above systolic pressure and gradually deflating it. The difference between the systolic pressure at which Korotkoff sounds first become audible during expiration and the pressure at which they are heard throughout all phases of respiration quantifies pulsus paradoxus (20 mm Hg in this patient). Inspiration causes an increase in systemic venous return, resulting in increased right heart volumes. Under normal conditions, this results in expansion of the right ventricle into the pericardial space with little impact on the left side of the heart. However, in conditions that impair expansion into the pericardial space (eg, acute cardiac tamponade), the increased right ventricular volume occurring with inspiration leads to bowing of the interventricular septum toward the left ventricle. This leads to a decrease in left ventricular (LV) end-diastolic volume and stroke volume, with a resultant decrease in systolic pressure during inspiration. (Choice A) Fixed LV outflow tract obstruction (eg, valvular aortic stenosis) can cause pulsus parvus et tardus, which is palpable as a slow-rising, low-amplitude pulse due to diminished stroke volume (pulsus parvus) and prolonged LV ejection time (pulsus tardus). (Choice B) Patients with chronic severe mitral regurgitation have a bounding pulse with a brisk upstroke due to increased LV ejection volumes. Arterial pulses are overall reduced in amplitude in patients with mitral stenosis due to reduced stroke volume. (Choice C) Myocardial ischemia or infarction can lead to decreased systemic blood pressure or hypotension due to reduced cardiac output, but it would not be expected to cause pulsus paradoxus. (Choice E) Peripheral vascular disease causes decreased pulse amplitude within the affected extremities. This is most commonly observed in the lower extremities, which will have diminished or absent distal pulses caused by widespread peripheral arterial disease. Educational objective: Pulsus paradoxus is defined by a decrease in systolic blood pressure of >10 mm Hg with inspiration. It is most commonly seen in patients with cardiac tamponade but can also occur in severe asthma, chronic obstructive pulmonary disease, and constrictive pericarditis. __________ References: Pulsus paradoxus. (http://www.ncbi.nlm.nih.gov/pubmed/23222878)

A 67-Year-Old Man Comes to the Emergency Department Due to Progressive