Diagnosis of Pulmonary Embolism Using Emergency Department Bedside Echocardiogram

A previously healthy 88-year-old female presented to the emergency department (ED) with a 4-day history of progressive shortness of breath, dyspnea on exertion, nonproductive cough, weakness, fatigue, and episodic fever. She had experienced mild, left-sided chest discomfort early in the course of her illness, which had resolved prior to presentation. Initial examination revealed a comfortable-appearing, pleasant, elderly woman. Her vital signs were notable for heart rate of 108 beats/min and oxygen saturation on room air of 84%. She was placed on 4 L of supplemental oxygen via nasal cannula, with improved oxygen saturation to 98%. The physical examination was remarkable only for mild tachycardia and bilateral, symmetric, chronic lower extremity edema. She had clear breath sounds with good air movement. The electrocardiogram (ECG) demonstrated sinus tachycardia with Q waves in leads V1-V3, and no old ECGs were available for comparison. A complete blood count, metabolic panel, and troponin were unremarkable, but B-type natriuretic peptide (BNP) was elevated at 9623 pg/mL. A chest radiograph did not show signs of acute cardiopulmonary disease. The bedside echocardiography performed by the emergency physician at this point was largely unremarkable; no pericardial effusion was evident, chamber size was appropriate, and there was normal global contractility (Figure 1, Video Clip S1, available as supporting information in the online version of this paper). The inferior vena cava was normal in size and contracted physiologically with inspiration (Figure 2, Video Clip S2, available as supporting information in the online version of this paper). Over the next hour, the patient deteriorated clinically, becoming cool, pale, diaphoretic, hypotensive, and increasingly tachycardic. She was given a 500-mL normal saline fluid bolus and the bedside echocardiogram was repeated. On this examination, the right atrium and ventricle were markedly enlarged and the septum was noted to bow into the left ventricle (Figure 3, Video Clip S3, available as supporting information in the online version of this paper). In addition, the inferior vena cava was dilated and noncollapsible on inspiration (Figure 4, Video Clip S4, available as supporting information in the online version of this paper). Based on these findings, a presumptive diagnosis of pulmonary embolism (PE) with acute cor pulmonale was made. A computed tomography angiogram of the chest demonstrated multiple bilateral filling defects consistent with PE. Thrombi were visualized in the lobar arteries of the left upper lobe, left lower lobe, lingula, right upper lobe, right middle lobe, and right lower lobe of the lung. After a fluid bolus, vital signs improved and systemic anticoagulation was initiated. The patient was admitted for continued treatment of PE and was successfully discharged several days later. In this case, early ultrasound evaluation in the setting of clinical deterioration led to prompt diagnosis and medical management of PE and acute cor pulmonale.

Figure 1.  Early apical four-chamber view. LA = left atrium; LV = left ventricle; RA = right atrium; RV = right ventricle.

Figure 2.  Early inferior vena cava view. IVC = inferior vena cava; RA = right atrium.

Figure 3.  Late apical four-chamber view showing right atrial and ventricular dilatation and septal deviation. RA = right atrium; RV = right ventricle.

Figure 4.  Late inferior vena cava (IVC) view showing IVC dilatation.

Emergency echocardiography has important clinical utility in the diagnosis and management of PE, particularly in hemodynamically unstable patients with unexplained shortness of breath, syncope, chest pain, or evidence of right heart failure.¹ In patients with large pulmonary emboli, abnormalities commonly seen on ultrasound include right ventricular dilatation and hypokinesis, right atrial enlargement and tricuspid regurgitation, paradoxical septal shift into the left ventricle, and diastolic left ventricular impairment.² Clinicians should remember, however, that a normal bedside echocardiogram in patients with a suspected PE cannot effectively rule out the diagnosis.^1,2 Small pulmonary emboli may not yield the characteristic ultrasound findings of acute cor pulmonale. As such, judicious use of bedside ultrasonography can provide a vital diagnostic tool to guide management in patients with suspected PE.