A 46-year-old man with a 30-pack-year smoking history develops right leg pain and swelling after returning from an overseas trip. He is diagnosed with a lower extremity deep venous thrombosis and is started on intravenous heparin. Shortly after being hospitalized, he develops right-sided weakness and facial droop. CT scan of the head reveals a left middle cerebral artery stroke. Which of the following physical examination findings is most likely to be present in this patient?

Question

A 46-year-old man with a 30-pack-year smoking history develops right leg pain and swelling after returning from an overseas trip.  He is diagnosed with a lower extremity deep venous thrombosis and is started on intravenous heparin.  Shortly after being hospitalized, he develops right-sided weakness and facial droop.  CT scan of the head reveals a left middle cerebral artery stroke.  Which of the following physical examination findings is most likely to be present in this patient?

Quizplus · Accepted Answer

A cerebrovascular event (eg, transient ischemic attack, stroke) in the setting of known venous thromboembolic disease is suspicious for paradoxical embolism. Paradoxical emboli originate in the systemic venous circulation (lower or upper extremities) and enter the systemic arterial circulation via an intracardiac or intrapulmonary shunt. They can occur in patients with patent foramen ovale, atrial septal defects, ventricular septal defects, or large pulmonary arteriovenous malformations. Atrial septal defects with left-to-right shunting typically cause wide and fixed splitting (no change with respiration) of the second heart sound (S2). Patients may also have a mid-systolic ejection murmur over the left upper sternal border resulting from increased flow across the pulmonic valve and a mid-diastolic rumble due to increased flow across the tricuspid valve. Importantly, a paradoxical embolism can occur even in patients with net left-to-right shunting due to transient reversal of the shunt during periods of elevated right-sided pressure (eg, early ventricular systole, straining during coughing or defecation). (Choice A) An early diastolic decrescendo murmur is characteristic of aortic regurgitation. Inhaled amyl nitrite produces marked vasodilatation, which reduces systemic arterial pressure and regurgitant flow (lessening the murmur). (Choice B) A systolic ejection murmur that increases in intensity with standing can be heard in patients with hypertrophic cardiomyopathy (due to a decrease in left ventricular outflow tract size). In contrast, the murmur of valvular aortic stenosis decreases in intensity upon standing. (Choice C) Mitral or tricuspid valve stenosis can cause a diastolic murmur with presystolic accentuation due to atrial contraction. With mild stenosis, the murmur may only be audible during the accentuation phase in late diastole; atrial fibrillation may cause the murmur to disappear completely. (Choice D) The midsystolic click of mitral valve prolapse occurs earlier with inspiration due to the reduced left ventricular volume caused by decreased venous return to the left heart. Educational objective: Paradoxical embolism occurs when a thrombus from the venous system crosses into the arterial circulation via an abnormal connection between the right and left cardiac chambers (eg, patent foramen ovale, atrial septal defect, or ventricular septal defect). Atrial left-to-right shunts cause wide and fixed splitting of S2 and can facilitate paradoxical embolism due to periods of transient shunt reversal (eg, during straining or coughing). __________ References: Paradoxical embolism. (http://www.ncbi.nlm.nih.gov/pubmed/25060377)

A 46-Year-Old Man with a 30-Pack-Year Smoking History Develops Right