Electrical Alternans: An Echocardiographic Visual Reference
Version of Record online: 14 MAY 2010
© 2010 by the Society for Academic Emergency Medicine
Academic Emergency Medicine
Volume 17, Issue 6, pages e48–e49, June 2010
How to Cite
Sisson, C. A. (2010), Electrical Alternans: An Echocardiographic Visual Reference. Academic Emergency Medicine, 17: e48–e49. doi: 10.1111/j.1553-2712.2010.00769.x
- Issue online: 2 JUN 2010
- Version of Record online: 14 MAY 2010
A 57-year-old male was brought to the emergency department with a chief complaint of left flank and left-sided chest pain. The pain was described as sharp or stabbing in nature and had been present for 1 week. The patient had a history of coronary artery disease but described the pain as “different” than his typical angina. Pertinent associated symptoms included shortness of breath and an increase in pain with inspiration and position changes. His pain was nonradiating, and there was no increased pain with exertion. This patient’s past medical history included hypertension, hepatitis C, tobacco use, alcoholism, and previous cardiac catheterization with stent placement.
On arrival, the patient was in no acute distress. His vital signs were heart rate 104 beats/min, blood pressure 101/77 mm Hg, and respiratory rate 20 breaths/min, with a room air oxygen saturation of 100%. His physical examination showed mild bibasilar rales, jugular venous distension, and distant heart sounds. An electrocardiogram (Figure 1) was performed immediately upon arrival and showed total electrical alternans. Within the same lead, the variation in QRS magnitude was obvious (Figure 2), but the P-wave and T-wave variation was much more subtle (Figure 3).
At this time, bedside echocardiography was performed and revealed a large pericardial effusion (Figure 4). The heart was seen to dramatically “swing” within the pericardial fluid, giving an excellent visual reference for the observed electrocardiographic findings (Video Clip S1). Also visualized on this bedside echocardiogram was obvious abnormal right ventricular collapse suspicious for tamponade physiology. At this point, an M-mode interrogation line was placed through the right ventricular free wall and mitral valve leaflets using the long-axis parasternal window. Using M-mode, right ventricular free wall collapse was noted to occur at the same time as mitral valve opening (diastole), confirming tamponade physiology (Video Clip S2).
Given that the patient was stable, cardiology was consulted and took the patient to undergo pericardiocentesis and placement of a drainage catheter. Roughly 800 mL of fluid was removed from the pericardial space on initial drainage. A computed tomography scan of the chest revealed a left upper lobe lung carcinoma later diagnosed as Stage 4 non–small cell lung cancer. The drain was eventually removed and the patient was discharged with the diagnosis of lung cancer and malignant pericardial effusion.
Video Clip S1. Bedside echocardiography demonstrating “swinging” of the heart within the pericardial fluid that produces the electrocardiographic pattern of electrical alternans.
Video Clip S2. Bedside echocardiography demonstrating the diagnosis of cardiac tamponade using the M-mode function on the ultrasound machine.
The video clips are in QuickTime.
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