Pulmonary Embolism Presenting with Evolving Electrocardiographic Abnormalities Mimicking Anteroseptal Myocardial Infarction: A Case Report

Objectives: To report a case with dynamic ST segment elevation suggestive of anteroseptal acute myocardial infarction (AMI) that proved to be bilateral pulmonary thromboembolism (PTE). Clinical Presentation and Intervention: A 50-year-old woman with syncope was transferred to the emergency department. Findings from the admission electrocardiogram were suggestive of anteroseptal AMI; however, coronary angiography revealed that the patient had normal coronary arteries. On further evaluation, the patient was found to have massive bilateral PTE. Conclusion: This report emphasizes the role of evolving electrocardiographic changes in the diagnosis of PTE, particularly in patients with chest pain and ST segment elevation suggestive of acute coronary syndrome. Copyright © 2011 S. Karger AG, Basel Received: August 19, 2010 Accepted: February 22, 2011 Uğur Canpolat Department of Cardiology Hacettepe University TR–06100 Sihhiye, Ankara (Turkey) Tel. +90 312 305 1780, E-Mail dru_canpolat @ yahoo.com © 2011 S. Karger AG, Basel 1011–7571/11/0206–0577$38.00/0 Accessible online at: www.karger.com/mpp Özer/Yorgun/Canpolat/Ateş/Aksöyek Med Princ Pract 2011;20:577–580 578 on the right lower lobe of lung and a 2/6 systolic murmur in the mesocardiac area. Complete blood count, cardiac troponins and blood chemistry were within normal limits except the serum glucose level indicating hyperglycemia (270 mg/dl). Initial arterial blood gas analysis revealed a pH of 7.51, an oxygen pressure of 65 mm Hg, carbon dioxide pressure of 36 mm Hg, oxygen saturation of 90% and a bicarbonate concentration of 24 mmol/l. The electrocardiogram of the patient had been in sinus rhythm without right bundle branch block (RBBB) 2 weeks previously ( fig. 1 a). ECG showed sinus tachycardia (112/min), RBBB with ST segment elevation on precordial leads V 1–3 and DII, DIII, aVF and reciprocal changes in DI and aVL ( fig. 1 b). Right precordial leads revealed ST segment elevations (2 mm) and q waves (2 mm) in V 4–6 R ( fig. 1 c). As a result, therapy for acute coronary syndrome was initiated (aspirin, clopidogrel, unfractionated heparin, atorvastatin), and arrangements were made for emergency coronary angiography for suspected acute coronary occlusion; however, the coronary angiogram revealed normal coronary arteries. During the course an atrial tachycardia with a ventricular rate of 164/min was observed, and afterwards sinus tachycardia resumed spontaneously. After cardiac catheterization, transthoracic echocardiography revealed right ventricular dilatation, severe tricuspid insufficiency, pulmonary hypertension (60 mm Hg) and displacement of the interventricular septum into the left ventricle; however, left ventricular systolic function was normal. Also, the patient demonstrated ‘McConnell’s sign’, which is known as ventricular freewall hypokinesia with preservation of right ventricular apical motion and was reported in case of massive PTE [4] . Multidetector computed tomography pulmonary angiography (Somatom Definition, Siemens, Erlangen, Germany) showed bilateral pulmonary arterial thrombus with dilated right ventricle and displaced interventricular septum into the left side, but lower extremity venography did not show any finding compatible with deep venous thrombosis. Intravenous heparin was resumed by an infusion of 1,000 U/h, and the infusion was adjusted according to a previously established activated thromboplastin time. In the second hour of unfractionated heparin infusion, the patient was stabilized, felt better and ECG showed sinus rhythm with RBBB without ST segment elevation ( fig. 2 a). Twenty-four-hour ECG revealed sinus rhythm, and RBBB disappeared with ST segment depression in V 1–3 , consistent with a right ventricular strain pattern ( fig. 2 b). The remaining hospital stay of the patient was uneventful. Anticoagulation with warfarin was initiated before discharge from the hospital; the patient is doing well at 1 month of followup.