The Journal of Emergency Medicine, Vol. -, No. -, pp. 1–4, 2016 Ó 2016 Elsevier Inc. All rights reserved. 0736-4679/$ - see front matter
http://dx.doi.org/10.1016/j.jemermed.2016.05.006
Ultrasound in Emergency Medicine
LEFT ATRIAL COMPRESSION CAUSED BY AN INTRAPERICARDIAL HEMATOMA AFTER CORONARY ARTERY BYPASS GRAFT SURGERY Jeroen Walpot, MD and Masoud Sadreddini, MD Department of Cardiology, Admiraal De Ruyter Ziekenhuis, Vlissingen and Goes, The Netherlands Corresponding Address: Jeroen Walpot, MD, Department of Cardiology, Admiraal De Ruyter Ziekenhuis, Koudekerkseweg 88, Postbus 3200, 4380 DD Vlissingen, The Netherlands
, Abstract—Background: Left atrial compression (LAC) is an uncommon condition that causes left ventricular inflow obstruction. The clinical and pathologic features are similar to those of mitral stenosis. Impaired left ventricular filling may cause hypotension, syncope, or shock. The increased left atrial pressure causes retrograde increase of the pressure throughout the pulmonary circulation with subsequent signs of congestion. Case Report: An 84-year-old man presented with LAC caused by a focal tamponade related to a pericardial hematoma as a complication of coronary artery bypass graft (CABG) surgery. The formation of the hematoma occurred 3 weeks postsurgery. The echocardiographic study before discharge at day 12 after CABG surgery showed neither a focal hematoma nor a tamponade. The diagnosis was made 6 days later. Why Should an Emergency Physician Be Aware of This?: Intrapericardial tamponade caused by bleeding is a known complication of CABG surgery in the early postoperative stage. However, emergency physicians should be aware that a postoperative hematoma may also present as a focal tamponade because of postoperative adhesion by scar formation. The literature of LAC is limited. The most reported causes of LAC are compression caused by structures of the gastrointestinal tract, followed by thoracic aortic pathology. A Medline search for the terms
‘‘left atrial compression and hematoma’’ and ‘‘left atrial compression and intrapericardial hematoma’’ found only 31 and 4 hits, respectively. We also briefly discuss the import role of bedside echocardiography in the diagnostic process of LAC in the emergency medicine department. Ó 2016 Elsevier Inc. All rights reserved. , Keywords—echocardiography; focal pericardial tamponade; intrapericardial hematoma; left atrial compression
INTRODUCTION We describe an 84-year-old man who presented to the Department of Emergency Medicine because he was in cardiogenic shock. He had developed a focal tamponade caused by an intrapericardial hematoma in the third week after coronary artery bypass graft (CABG) surgery. The hematoma caused left atrial compression (LAC). Intrapericardial tamponade is a known complication of CABG in the early stages of the postoperative period. In a recent study, postoperative tamponade was identified as one of the causes of prolonged stay in the intensive care unit after CABG surgery (1). Postoperative tamponade after CABG surgery within the first weeks after discharge is encountered by most cardiologists a few times during their career. However, a local tamponade caused by a hematoma causing LAC is a rare condition. LAC causes left
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RECEIVED: 13 November 2015; FINAL SUBMISSION RECEIVED: 16 January 2016; ACCEPTED: 5 May 2016 1
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ventricular inflow obstruction. Consequently, it may mimic the symptoms of mitral stenosis. The diagnosis of LAC caused by an intrapericardial hematoma is often challenging. Our case shows the important role of echocardiography in the emergency department. CASE REPORT An 84-year-old man with a medical history of hypertension underwent CABG surgery because of unstable angina pectoris. His coronary angiographic study revealed 3-vessel disease with severe left main stenosis. The initial postoperative course was complicated by paroxysmal atrium fibrillation. His CHADSVASC score, to determine the embolic risk due to atrial fibrillation, was 4, and oral anticoagulant therapy was initiated. The postoperative recovery of this octogenarian was unremarkable. He was discharged at day 14 in good condition. However, he presented to the emergency department on postsurgery day 18 with complaints of chest pain and signs of shock. He mentioned an episode of interscapular chest discomfort that began the night before admission. The complaints began approximately 12 hours before arrival at the hospital. The physical examination revealed that his blood pressure was 89/54 mm Hg with a pulse of 64 beats/min. The patient was pale. There was neither a murmur nor pulsus paradoxus. The auscultation of the lungs was unremarkable and there was no edema on the limbs. The laboratory results were as follows: hemoglobin 6.0 mmol/L (6.5 mmol/L before discharge 5 days earlier), an international normalized ratio of > 8, preserved kidney function, a lactate level of 1.9 mmol/L, an N-terminal of
the prohormone brain natriuretic peptide of 425 pmol/L, and a C-reactive protein level of 25. An electrocardiogram revealed a sinus rhythm of 68 beats/min. There were mild intraventricular conduction disturbances. The repolarization was unchanged compared with previous electrocardiograms. A chest radiograph did not show pleural effusion. There were signs of mild congestion without pulmonary edema. A transthoracic echocardiogram (TTE) study performed by an experienced cardiac ultrasonographer revealed preserved left and right ventricular function and a large mass at the left atrial site of the heart (Figure 1). However, the TTE study could not accurately confirm whether the mass was located within the left atrium (LA) or within the pericardial cavity. In addition, dissection of the aorta could not be excluded. Given the patient’s medical history and international normalized ratio of >8, focal tamponade caused by an intrapericardial hematoma with left atrial obstruction was thought to be the most likely diagnosis. Nonetheless, it was felt that the aforementioned questions had to be answered correctly before referring the patient for cardiac surgery. The cardiologist was called for an urgent consultation. He proposed an urgent transesophageal echocardiography (TEE) study in the emergency department to provide a definite, quick bedside response to these important issues. TEE was performed without sedation by a cardiologist, was able to resolve the 2 questions. TEE allowed a clear delineation of mass from the atrial wall, confirming the intrapericardial localization of the hematoma (Figure 2; Videos 1 and 2, available online at www.jemjournal.com). The TEE study also excluded dissection of the ascending aorta.
Figure 1. (A) 5 chamber view 12 days after cardiac artery bypass graft surgery. Note the absence of the intrapericardial mass. (B) The same view on admission to the emergency department 6 days later. There is a mass (*) obliterating the left atrium. This image does not allow delineation of the mass from the atrial wall.
LAC Caused by Intrapericardial Hematoma after CABG
Figure 2. Transesophageal echocardiography at 143 shows compression of the intrapericardial mass (*) on the left atrium. This image allows delineation of the left atrial wall from the mass and therefore confirms intrapericardial localization of the hematoma. LV = left ventricle.
A computed tomography scan confirmed of the findings of the TEE study and excluded any other intrathoracic pathology (Figure 3). The patient was referred for urgent rethoracotomy, and a 250 cm2 hematoma was removed. The patient recovered well. DISCUSSION LAC is uncommon. The medical literature on this subject is limited (<360 articles). We report a case of LAC caused by an intrapericardial hematoma in the third week after CABG surgery. Most reports on LAC describe an extracardiac cause of compression of the left atrium. A Medline search for the terms ‘‘left atrial compression and hematoma’’ and ‘‘left atrial compression and intrapericardial hematoma’’ found only 31 and 4 hits, respectively. Three case reports have described a focal tamponade with LAC as a complication of a percutaneous coronary
Figure 3. A computed tomography scan of the chest after administration of radiologic contrast. Note the large mass obliterating the left atrial cavity.
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intervention (PCI) of the left circumflex artery (LCX) (2–4). A life-threatening cardiac tamponade caused by a coronary artery perforation is a rare complication of PCI. It has a reported incidence of 0.1% to 0.3% and accounts for 20% of all referrals for emergency coronary bypass surgery (4,5). It is noteworthy that in 1 of these cases, the PCI was performed 6 months after CABG surgery. The authors speculated that the atypical presentation of a focal tamponade instead of generalized pericardial effusion could have been a consequence of postoperative adhesion by scar formation. In the last few decades, the literature regarding LAC has been subjected to review twice. D’Cruz et al. proposed a classification of LAC based on the impact of LAC on the left atrial function and anatomy (6). A subdivision into 3 classes was postulated as follows: 1) proximity (i.e., a contiguous or adjacent structure without chamber deformation); 2) encroachment (i.e., distortion of the normal left atrial architecture without hemodynamic consequences); and 3) compression (i.e., where deformation of the left atrium leads to severe inflow obstruction with symptoms) (6). According to this classification system, our patient had to be classified in the compression group because there were symptoms of shock. In 2008, van Rooijen and van den Merkhof proposed a new classification according to the etiology of LAC (7). The affecting anatomic structures were divided into 4 groups: 1) gastrointestinal structures, such as hiatus hernia, achalasia, and esophageal hematoma, which are the most common causes of LAC; 2) mediastinal structures, such thymoma and lymphoma; 3) aorta and intrapericardial structures; and 4) pulmonary structures, such as long tumors and bronchogenic cysts (7). In hemodynamically unstable patients with LAC, determination of the etiology of LAC is mandatory because the treatment of severe symptomatic LAC requires relief of its cause. Therefore, the search for the etiology of LAC inevitably precedes its treatment. The diagnosis of LAC and its etiology is often challenging. This case shows the value and limitations of TTE in the emergency department. The patient presented with symptoms of shock 3 weeks after CABG surgery. The TTE study immediately diagnosed left ventricular inflow obstruction caused by a mass in the region of the left atrium. However, this TTE study could not definitively address an important question: was this a mass inside the left atrium or a pericardial hematoma compressing the left atrium? Given the patient’s medical history of recent CABG surgery, a local tamponade with LAC was considered the most likely diagnosis. Adhesion because of healing after surgery was thought to have caused a focal hematoma. Nonetheless, it was felt that definitive confirmation was needed.
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A TEE study was then performed in the emergency department. The TEE study accurately answered 2 main questions. First, it confirmed that the mass was localized within the pericardium and not the left atrium. Second, it definitively excluded dissection of the ascending aorta as the cause of intrapericardial hematoma. As the latter life-threatening diagnosis was eliminated, the patient was transported to the radiology department to perform a computed tomography scan of the thorax to rule out other pathology in the chest before referral to a hospital with facility for cardiac surgery. Of the 3 imaging modalities (i.e., TTE, TEE, and computed tomography), TEE was the only modality that could definitely delineate the left atrial wall from the mass and therefore confirm the intrapericardial localization of the mass in a beside approach. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS? Emergency physicians should be aware that a postoperative hematoma after CABG surgery may present as a focal tamponade instead of a generalized effusion as a consequence of postoperative adhesion by scar formation. We report the case of 84-year-old man with LAC caused by a local tamponade caused by an intrapericardial hematoma. LAC is a rare clinical entity, and local compression of the left atrium because of an intrapericardial cause is extremely rare. This case also shows the important role of echocardiography in the emergency department. The TTE study immediately diagnosed left
ventricular inflow obstruction caused by a mass in the region of the left atrium. TEE was able to accurate diagnose the intrapericardial localization of the mass. TEE also definitively excluded dissection of the ascending aorta as the cause the intracardiac hematoma.
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SUPPLEMENTARY DATA Supplementary data related to this article can be found at http://dx.doi.org/10.1016/j.jemermed.2016.05.006.
Streaming videos: Two brief real-time video clips that accompany this article are available in streaming video at www.journals.elsevierhealth.com/periodicals/jem. Click on Video Clips 1 and 2.