The prevalence of myocardial involvement in influenza infection ranges from 0% to 11%
depending on the diagnostic criteria used to define myocarditis. Whether such an association
holds for the novel influenza A strain, pandemic-2009-H1N1, remains unknown. The clinical
presentation of myocarditis varies and often mimics myocardial infarction. Although history,
physical examination, laboratory data points, and electrocardiogram are helpful in distinguishing
myocarditis from myocardial infarction, differential diagnosis can sometimes be
difficult. Here, we present the first known report of acute myocarditis mimicking acute myocardial
infarction associated with the pandemic influenza A virus (H1N1) infection. (Cardiol J
2011; 18, 5: 552&#8211;555

Basar, Cengiz

Erden, Emine Çakcak

Erden, Ismail

Özhan, Hakan

Cardiology Journal

English

Via Medica Journals

CASE REPORTCardiology Journal2011, Vol. 18, No. 5, pp. 552–55510.5603/CJ.2011.0012Copyright © 2011 Via MedicaISSN 1897–5593552 www.cardiologyjournal.orgAddress for correspondence: Dr. Ismail Erden, Duzce Universitesi, Düzce Tip Fakültesi 81620 Konuralp Düzce, Turkey,tel: +90380 542 13 92-5766, fax: +903805421387, e-mail: iserdemus@yahoo.comReceived: 31.03.2010 Accepted: 27.04.2010Acute myocarditis mimicking acutemyocardial infarction associated withpandemic 2009 (H1N1) influenza A virusIsmail Erden1, Emine Çakcak Erden2, Hakan Özhan1, Cengiz Basar11Department of Cardiology, Duzce University, Düzce Medical School, Turkey2Department of Cardiology, Hayri Sivrikaya Hospital, TurkeyAbstractThe prevalence of myocardial involvement in influenza infection ranges from 0% to 11%depending on the diagnostic criteria used to define myocarditis. Whether such an associationholds for the novel influenza A strain, pandemic-2009-H1N1, remains unknown. The clinicalpresentation of myocarditis varies and often mimics myocardial infarction. Although history,physical examination, laboratory data points, and electrocardiogram are helpful in distin-guishing myocarditis from myocardial infarction, differential diagnosis can sometimes bedifficult. Here, we present the first known report of acute myocarditis mimicking acute myo-cardial infarction associated with the pandemic influenza A virus (H1N1) infection. (Cardiol J2011; 18, 5: 552–555)Key words: pandemic-2009-H1N1, myocarditis, mimics myocardial infarctionIntroductionAcute myocarditis is a well-recognized, albeitrare, manifestation of numerous viral infectionswith a broad spectrum of symptoms and clinical fea-tures [1]. The prevalence of myocardial involve-ment in influenza infection ranges from 0% to 11%,depending on the diagnostic criteria used to definemyocarditis [2, 3]. Whether such an associationholds for the novel influenza A strain, pandemic--2009-H1N1, remains unknown.A few case reports and series [4, 5] representthe incidental diagnoses of influenza-associatedacute  myocarditis with the pandemic 2009-H1N1influenza A virus infection, but the true prevalenceremains unknown.Although, there are many case reports of acutemyocarditis mimicking [6–9] acute myocardial in-farction, here we present the first known report ofacute myocarditis mimicking acute myocardial in-farction associated with the pandemic H1N1 influ-enza A virus infection.Case reportA 34 year-old woman was admitted to our hos-pital with moderate to severe retrosternal chestpain, emerging six hours before, radiating to back.The pain had an acute onset, progressive course anda compressing nature. She perceived no changes inthe quality of pain with position or on inspiration.Within the past week, she had experienced fever,cough, sore throat, nausea and shortness of breath.There was no history of smoking, diabetes, hyper-tension, dyslipidemia, family history of coronaryartery disease or cocaine abuse. Her initial heartrate was 92 beats/min; temperature 37.6°C, bloodpressure 112/72 mm Hg, and respiratory rate24 breaths/min with an oxygen saturation of 94% onroom air. Cardiac examination revealed normal S1,553Ismail Erden et al., Myocarditis pandemic H1N1 influenza A viruswww.cardiologyjournal.orgS2, with no additional sounds, murmurs or pericar-dial rub. The rest of the physical examination wasnormal. Electrocardiogram (ECG) on admission re-vealed sinus rhythm, normal QRS axis, a Q-waveat leads II, III, aVF and ST-segment elevation at leadsII, III, aVF with reciprocal ST segment depression atleads I, aVL (Fig. 1). On chest X-ray the heart sizewas normal and there were no signs of pulmonarypathology. Results of initial cardiac enzyme testsrevealed serum troponin I of 8.5 ng/mL (normal< 1 ng/mL), creatine kinase (CK) of 272 U/L (nor-mal 20–150 U/L), and CK-MB of 32.8 IU/L (normal< 25 IU/L). The laboratory investigations were oth-erwise normal except for elevated WBC (17200/mL)and ESR (68 mm/h). Echocardiography, which wasdone in the emergency department, showed a leftventricle with normal internal dimensions, an ap-parent regional hypokinesia of the posterior, mid-dle and basal segments of the inferior wall with anejection fraction of 45%. There was no evidence ofpericardial thickening or effusion. The patient wasstarted on aspirin, intravenous metoprolol, heparinand morphine therapy. The chest pain and ST ele-vation persisted despite sublingual and intravenousnitroglycerin administration, and she was taken asan emergency to the cardiac catheterization labo-ratory 30–35 min after admission. Coronary angio-graphy showed normal epicardial coronary arte-ries (Figs. 2, 3). The left ventricular end diastolicpressure was 17 mm Hg. Her chest pain resolvedspontaneously within a few hours.As the symptoms and clinical findings of thepatient fitted the criteria defined by World HealthOrganization for the influenza (H1N1) pandemia2009, we collected nasal wash specimens and thesewere sent to the University of Istanbul VirologyLaboratory working as the National Influenza Re-ference Laboratory (NIRL) in Turkey. Without wait-ing for the laboratory test results, the patient wastreated with oseltamivir (Tamiflu, Roche, Basle,Switzerland) 75 mg orally twice a day for five days. Overthe following days, a reverse-transcriptase polymerasechain reaction test of NIRL showed a postitive result.CK and CK-MB levels peaked on the 2nd day of hos-pitalization at 835 IU/L and 189 IU/L respectively.Over the following days, ST-segment elevationsgradually decreased and negative T-waves appearedat the same leads and precordial leads (Fig. 4).The patient was discharged on angiotensin-con-verting-enzyme inhibitor and beta-blocker therapyin good condition without chest pain. Two weekslater, she remained asymptomatic and echocardio-graphic assessment showed that the regional wallmotion abnormality was greatly improved.DiscussionInfluenza A virus-associated myocarditis israre, with only a few cases reported in the litera-ture [2]. Here, we present the first known reportof acute myocarditis mimicking acute myocardialinfarction associated with the 2009 pandemic influ-enza A virus (H1N1) infection.The prevalence of influenza-associated myo-carditis is not known because of a lack of compre-hensive screening, with only a handful of clinicalcases and autopsy findings reported in the litera-ture [2, 3]. Whether such an association holds forthe novel influenza A strain, pandemic-2009-H1N1,remains unknown.Martin et al. [4] reviewed 123 sequential cas-es of patients hospitalized with pandemic-2009--H1N1 influenza A at a single academic medical cent-er in the United States between April 1 and Octo-ber 31, 2009. They identified that 4.9% (6/123) ofpatients had either new or worsened left ventricu-lar dysfunction. Two thirds (4/6) of the cases hadfollow-up echocardiograms, and in all four left ven-tricular function improved. Therefore, they foundthat potentially reversible cardiac dysfunction isa relatively common complication associated withhospitalized pandemic-2009-H1N1 influenza. In ourcase, we also found that left ventricular function washighly improved in follow-up.Bratincsak et al. [5] documented four caseswithin a 30-day period in 2010. Comparing them totheir previous experience, they declared that it waspossible that H1N1 influenza A virus was more com-monly associated with a severe form of myocardi-tis than previously encountered influenza strains,and that those observations warranted a high indexof suspicion for myocarditis in children with H1N1influenza A infection.However,  there are many case reports of acutemyocarditis mimicking acute myocardial infarction[6–9]. A thorough and detailed history, examinationand ECG interpretation by an expert cardiologist ismandatory in this situation to avoid complicationsthat may arise from inaccurate diagnosis. Despitea low cardiac risk score supportinga diagnosis of myo-carditis in our patient, the localized dramatic infe-rior ST-segment elevation and segmental left ven-tricular dysfunction raised the possibility of an acutecoronary syndrome. Differential diagnosis often re-quires cardiac catheterization. Diagnosis in thesekinds of patients is difficult, as they may not havean acute coronary syndrome. A diagnosis of myo-carditis needs to be kept in mind. Unfortunately, theclinical diagnosis of myocarditis remains a challenge554Cardiology Journal 2011, Vol. 18, No. 5www.cardiologyjournal.orgFigure 1. A. Electrocardiogram on admission revealed Q-wave at leads II, III, aVF and ST-segment elevation at leadsII, III, aVF with reciprocal ST segment depression at leads I, aVL; B. Electrocardiogram on discharge revealedST-segment elevations gradually decreased and negative T-waves appeared at the same leads and precordial leads.AB555Ismail Erden et al., Myocarditis pandemic H1N1 influenza A viruswww.cardiologyjournal.orgFigure 2. A. Left coronary angiogram in a right anterior oblique-cranial projection shows no significant coronaryartery disease; B. Right coronary angiogram shows no significant coronary artery disease.owing to the non-specific pattern of the clinical pre-sentation and the lack of universally accepted andstandardized diagnostic criteria. Primary percuta-neous coronary intervention should always be thetreatment of choice, since all of the preliminarysigns and test results may be confused with acutemyocardial infarction.AcknowledgementsThe authors do not report any conflict of inte-rest regarding this work.References1. Lieberman EB, Hutchins GM, Herskowitz A, Rose NR,Baughman KL. Clinicopathologic description of myocarditis.J Am Coll Cardiol, 1991; 18: 1617–1626.2. Mamas MA, Fraser D, Neyses L. Cardiovascular manifestationsassociated with influenza virus infection. Int J Cardiol, 2008;130: 304–309.3. Onitsuka H, Imamura T, Miyamoto N et al. Clinical manifesta-tions of influenza a myocarditis during the influenza epidemic ofwinter 1998–1999. J Cardiol, 2001; 37: 315–323.4. Martin SS, Hollingsworth CL, Norfolk SG, Wolfe CR, Hollings-worth JW. Reversible cardiac dysfunction associated with pan-demic-2009-H1N1 influenza A. Chest, 2010; 137: 1195–1197.5. Bratincsak A, El-Said HG, Bradley JS, Shayan K, Grossfeld PD,Cannavino CR. Fulminant myocarditis associated with pandemicH1N1 influenza A virus in children. J Am Coll Cardiol, 2010; 55:928–929.6. Amini R, Nielsen R. Eosinophilic myocarditis mimicking acutecoronary syndrome secondary to idiopathic hyperosinophilicsyndrome: A case report. J Med Case Reports, 2010; 4: 40.7. Basic D, Gupta S, Kwong RY. Parvovirus B19-induced myocar-ditis mimicking acute myocardial infarction. Circulation, 2010;121: 40–42.8. Testani JM, Kolansky DM, Litt H, Gerstenfeld EP, Focalmyocarditis mimicking acute ST-elevation myocardial infarction.Tex Heart Inst J, 2006; 33: 256–259.9. Pomaraa C, Villanib A, D’Erricoa S, Riezzo I, Turillazzi E,Fineschi V. Acute myocarditis mimicking acute myocardialinfarction: A clinical nightmare with forensic implications. InterJ Cardiol, 2006; 112: 119–121.A B

Acute myocarditis mimicking acute myocardial infarction associated with pandemic 2009 (H1N1) influenza A virus

WOS: 000297189200012PubMed: 21947992The prevalence of myocardial involvement in influenza infection ranges from 0% to 11% depending on the diagnostic criteria used to define myocarditis. Whether such an association holds for the novel influenza A strain, pandemic-2009-H1N1, remains unknown. The clinical presentation of myocarditis varies and often mimics myocardial infarction. Although history, physical examination, laboratory data points, and electrocardiogram are helpful in distinguishing myocarditis from myocardial infarction, differential diagnosis can sometimes be difficult. Here, we present the first known report of acute myocarditis mimicking acute myocardial infarction associated with the pandemic influenza A virus (H1N1) infection. (Cardiol J 2011; 18, 5: 552-555

Erden, İsmail

Başar, Cengiz

Duzce University Open Access

https://journals.viamedica.pl/cardiology_journal/article/download/21209/16813

Acute myocarditis mimicking acute myocardial infarction associated with pandemic 2009 (H1N1) influenza A virus

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