Electrical Alternans: An Echocardiographic Visual Reference

Abstract

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). Presenting 12-lead electrocardiogram. Leads V2 and V3, showing obvious variation in the amplitude and direction of the QRS complexes. Lead V1 showing subtle changes in P-wave and T-wave morphology; red arrows and blue arrows correspond to separate cardiac cycles. 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). Large pericardial effusion. 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. Please note: Wiley Periodicals Inc. is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing material) should be directed to the corresponding author for the article. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.