In the absence of diagnostic imaging, chest pain can represent a diagnostic dilemma, especially, if the patient\u27s condition requires immediate action. We present a case of a patient with signs of obstructive shock that turned out to result from an acute aortic dissection (AAD) and consequent cardiac tamponade. Before the correct diagnosis was made, myocardial infarction and/or pulmonary embolism were suspected and the patient was treated with antithrombotic and anticoagulant drugs, which are contraindicated in AAD. We discuss the correct procedures and treatment in suspected AAD

Jana Makuc

Martin Tretjak

English

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35www.signavitae.comMisdiagnosed acute aortic dissection type AABSTRACTIn the absence of diagnostic imaging, chest pain can represent a diagnostic dilemma, especially, if the patient’s condition requires immediate action. We present a case of a patient with signs of obstructive shock that turned out to result from an acute aortic dissection (AAD) and consequent cardiac tamponade. Before the correct diagnosis was made, myocardial infarction and/or pulmonary embolism were suspected and the patient was treated with antithrombotic and anticoagulant drugs, which are contraindicated in AAD. We discuss the correct procedures and treatment in suspected AAD.CASE REPORT   SIGNA VITAE 2010; 5(2): 35 - 37Key words: acute aortic dissection, Stanford type A, misdiagnosisIntroductionAcute aortic dissection (AAD) is a medi-cal emergency with a high mortality rate, rising by approx. 1% per hour. It usually presents with severe, unrelent-ing chest pain of sudden onset. Pain can be described as ripping or tear-ing in nature, or stabbing or sharp in character. It can migrate as the dis-section extends down the aorta (17%). Less common signs and symptoms are related to organ hypoperfusion and include peripheral ischemic syndromes (19%), syncope (13%), myocardial inf-arction (13%), heart failure (8.8%) and neurologic symptoms (6.1%). (1-3) Cases of painless AAD have also been described. (4,5) Because of such heter-ogeneous clinical presentations, many incorrectly diagnosed cases escape notice. Approx. one third of patients ultimately diagnosed with AAD are first thought to have another diagnosis. The true incidence of AAD is therefore dif-ficult to determine, but is estimated to be 5-20/1,000,000. (6)AAD is classified based on the location and extent of dissection. The two most commonly used classification systems are the DeBakey system, which catego-rizes aortic dissection based on where the original intimal tear is located and the extent of the dissection (type I – III), and the functional Stanford system, dividing dissections into those involv-ing the ascending aorta (type A, more common) and those distal to the outlet of the left subclavian artery (type B). In general, type A dissections have a high-er in-hospital mortality rate (30%) and require immediate surgical treatment, whereas type B dissections have a bet-ter prognosis (10% in-hospital mortal-ity) and may be managed medically. The clinical outcome of AAD is eventu-ally determined by dissection type and timing of presentation, patient-related factors and the quality and experience of the individuals and institution provid-ing care. (1) Case reportA 52-year old male, previously healthy, was brought to our hospital because of sudden severe chest pain, fol-lowed by loss of consciousness few minutes later. The patient’s wife had witnessed the event and immediately called the rescue team. She told them the patient was feeling bad the whole day and had vomited a couple of times. On their arrival (within ten minutes), the patient showed signs of obstruc-tive shock: he was soporous, pale and sweaty, had cyanotic lips and evidently full neck veins. During initial assess-ment his heart rate was normocardic, but was continuously rising during treatment (from 90 to 112 bpm); his blood pressure stayed low (RR 60/35 mm Hg). Besides intravenous fluids, he immediately received oxygen via an Ohio oxygen mask, resulting in a rise in peripheral blood saturation from 82% to 91%. Because of suspected acute myocardial infarction (AMI) acetylsali-cylic acid (500 mg) was administered to the patient. This diagnosis seemed less probable later, when a normal ECG was recorded. Lacking diagnostic imaging, the physician in charge was left wavering between a diagnosis of acute aortic dissection and massive pulmonary embolism and decided for the latter. The patient therefore received 5000 IU of heparin intravenously and was rushed to our facility (a regional 36 www.signavitae.comREFERENCES1. Weigang E, Nienaber CA, Rehders TC, Ince H, Vahl CF, Beyersdorf F. Management of patients with aortic dissection. Dtsch Arztebl Int 2008;105(38):639-46.2. No M. Sudden excruciating chest pain - prehospital management. In: Grmec Š, Tušek-Bunc K, Kupnik D, editors. Acute conditions: signs, symptoms, syndromes, differential diagnosis and management: proceedings and algorithms. Maribor: Slovene Family Medicine Society SZD; 2003. p. 21-4.3. Benko D, Tretjak M, Rainer S. Cardiac tamponade resulting from acute aortic dissection type A – case report and diagnostic approach. In: Bruan A, Griar M, Klanar S, Fink A, editors. Emergency medicine: selected topics 6. Ljubljana: Slovenian Society for Emergency Medicine; 2000. p. 441-6.4. Ayrik C, Cece H, Aslan O, Karcioglu O, Yilmaz E. Seeing the invisible: painless aortic dissection in the emergency setting. Emerg Med J 2006;23(3):24.5. Nadour W, Goldwasser B, Biederman RW, Taffe K. Silent aortic dissection presenting as transient locked-in syndrome. Tex Heart Inst J 2008; 35(3):359-61.6. Auer J, Berent R, Eber B. Aortic dissection: incidence, natural history and impact of surgery. J Clin Basic Cardiol 2000;3:151-4.hospital). There, the patient’s clinical condition was unchanged, except for a pulse deficit on the left side of his body. Heart sounds were quiet, but there was no murmur. While waiting for computed tomography angiography (CTA), fast transthoracic echocardiography (TTE) examination was performed, showing a massive inhomogeneous pericar-dial effusion, most probably partially coagulated blood. CTA confirmed the high suspicion of a haemopericar-dium, resulting from rupture of a type A aortic dissection. Dissection extend-ed throughout the ascending aorta, also comprising the aortic arch and descending aorta above the branch-ing of the left renal artery. Because the patient’s blood pressure and heart rate seemed stable, no additional drugs were given (incl. protamine sulphate) and pericardiocentesis was not per-formed. The patient was urgently trans-ferred to a tertiary medical centre for operative treatment. There were no changes in his clinical condition dur-ing transport, but while being placed on the operating table, he went into cardiac arrest. After successful resus-citation a Bentall operation was per-formed, but had to be revised because of profuse postoperative haemorrhag-ing. Two weeks later the patient was discharged from hospital, subjectively feeling very well (except for a mild left arm paresis).DiscussionStudies show that 31-39% of AAD’s are initially misdiagnosed, most com-monly as AMI, which is said to be “a catastrophe in disguise” because of inappropriate treatment. Exposure to antithrombotic agents in misdiag-nosed AAD is associated with signifi-cantly higher rates of major bleeding, hemodynamic instability and greater in-hospital mortality. (7-10) Therefore, if AAD is highly suspected drugs influ-encing blood coagulation should not be administered until diagnosis is exclud-ed. Nevertheless, if an anticoagulant is given anyway, unfractionated heparin (in comparison to low molecular weight heparins) has the advantage of quick and complete reversal by protamine sulphate.While waiting for an appropriate imag-ing method (computed tomography angiography - CTA, magnetic reso-nance imaging (MRI), transoesopha-geal echocardiography (TEE) to confirm or exclude the diagnosis, it is neces-sary to control pain and reduce systolic blood pressure to values between 100 and 120 mmHg. Patients with profound hemodynamic instability need to be intubated and ventilated without delay. It remains controversial whether peri-cardiocentesis should be performed in the case of pericardial tamponade; this may be harmful as it lowers peri-cardial pressure and can cause recur-rent bleeding. When urgent surgery is needed, TEE in combination with TTE can be used as the sole diagnostic procedure. If more spatial resolution is necessary, CTA or MRI is used in addition. Some authors also recom-mend coronary angiography for all sta-ble patients, because chronic coronary atherosclerotic disease (present in 25% of patients) may worsen the surgical outcome, but this remains undeter-mined. (11)The aims of surgical intervention in type A (type I and II) AAD are to prevent aortic rupture and pericardial effusion leading to cardiac tamponade, to relieve aortic regurgitation and to prevent myocardial ischemia. A large variability of surgical techniques exists, depending on the anatomic conditions and the condition of the aortic valve. (11)Although the clinical outcome is deter-mined by a variety of factors, the key in management of AAD is to maintain a high level of suspicion for this diag-nosis.37www.signavitae.com7. Hansen MS, Nogareda GJ, Hutchison SJ. Frequency of and inappropriate treatment of misdiagnosis of acute aortic dissection. Am J Cardiol 2007;99(6):852-6.8. Luo JL, Wu CK, Lin YH, Kao HL, Lin MS, Ho YL, et al. Type A aortic dissection manifesting as acute myocardial infarction: still a lesson to learn. Acta Cardiol 2009;64 (4):499-504.9. Asouhidou I, Asteri T. Acute aortic dissection: be aware of misdiagnosis. BMC Res Notes 2009;2:25.10. Marek D, Nemec P, Herman M, Gwozdziewicz M, Troubil M, Lukl J. Mistakes in dealing with aortic dissection. Lessons from three warning cases. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2008;152(2):283–27.11. Erbel R, Alfonso F, Boileau C, Dirsch O, Eber B, Haverich A, et al. Recommendations of the Task Force on Aortic Dissection, European Society of Cardiology. Diagnosis and management of aortic dissection. Eur Heart J 2001;22:1642–81.

Misdiagnosed acute aortic dissection type A

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