Exertional Syncope in an Athlete

HomeCirculation: Cardiovascular ImagingVol. 13, No. 4Exertional Syncope in an Athlete Free AccessCase ReportPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissionsDownload Articles + Supplements ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toSupplemental MaterialFree AccessCase ReportPDF/EPUBExertional Syncope in an AthleteThe Answer is in the History and Exam Madeline K. Mahowald, MD, Erin A. Fender, MD, MS, Abhiram Prasad, MD and Rick A. Nishimura, MD Madeline K. MahowaldMadeline K. Mahowald Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN (M.K.M., A.P., R.A.N.). , Erin A. FenderErin A. Fender Division of Cardiology, Department of Internal Medicine, Christiana Care Health System, Newark, DE (E.A.F.). , Abhiram PrasadAbhiram Prasad Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN (M.K.M., A.P., R.A.N.). and Rick A. NishimuraRick A. Nishimura Rick A. Nishimura, MD, Department of Cardiovascular Diseases, Mayo Clinic, 200 1st St SW, Rochester, MN 55905. Email E-mail Address: [email protected] Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN (M.K.M., A.P., R.A.N.). Originally published25 Mar 2020https://doi.org/10.1161/CIRCIMAGING.119.009992Circulation: Cardiovascular Imaging. 2020;13:e009992A 52-year-old male amateur athlete presented with exertional syncope after 10 years of progressive angina. He had previously been evaluated at another institution for these symptoms with an exercise positron emission scan scan that showed ST-segment depression on the ECG at peak exercise (Figure 1) but no exercise-induced arrhythmias or evidence of ischemia on perfusion imaging. Computed tomography of the coronary arteries, transthoracic echocardiogram, and eventually angiography were all unrevealing, and he was referred to our institution for further care.Download figureDownload PowerPointFigure 1. Exercise stress test showed 4-mm ST-segment depression on ECG at peak exercise, but perfusion imaging and later coronary angiogram showed no ischemia or significant stenosis.Upon examination, there was a normal cardiac examination, and no murmur was present at rest or elicited with Valsalva. However, due to his history of symptoms on exertion, repetitive squats were performed for 30 seconds, and a loud 3/6 systolic crescendo-decrescendo murmur became appreciable on auscultation. Labs were normal. An echocardiogram revealed normal left ventricle dimensions and ejection fraction; there was a mild sigmoid bulge at the basal septum with maximal thickness of 12 mm. There was a nightcap mitral valve due to elongation of the leaflets resulting in excessive coaptation during systole (Figure 2). There was no outflow gradient at rest, but Valsalva maneuver unmasked dynamic outflow tract obstruction mediated by systolic anterior motion of the mitral valve (Figure 3) with a maximum gradient of 46 mm Hg (Figure 4, middle), which increased to 61 mm Hg following administration of amyl nitrate (Figure 4, right; Movies I through III in the Data Supplement, showing mitral valve at rest and with amyl nitrate).Download figureDownload PowerPointFigure 2. A nightcap mitral valve, here shown during isovolumic contraction, is characterized by leaflets protruding beyond the mitral annulus. The elongated mitral valve leaflets often present in hypertrophic cardiomyopathy make them more susceptible to drag forces and subsequent obstruction. Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.Download figureDownload PowerPointFigure 3. Inhaled amyl nitrate unmasks systolic anterior motion of the mitral valve leading to left ventricular outflow tract obstruction. Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.Download figureDownload PowerPointFigure 4. Left ventricular outflow tract Doppler flow at rest (left), during Valsalva maneuver (middle) and during inhalation of amyl nitrate and concomitant Valsalva maneuver (right). There was no subaortic gradient at rest. Maximum instantaneous Doppler gradient during Valsalva was 46 mm Hg and increased to 61 mm Hg with the addition of inhaled amyl nitrate.Cardiac magnetic resonance imaging was notable for a maximum septal diameter of 11 mm and no delayed gadolinium enhancement. The patient is currently minimally symptomatic following initiation of metoprolol, fludrocortisone, and hydration.Hypertrophic cardiomyopathy is characterized by myocardial hypertrophy and is frequently associated with abnormalities of the mitral valve. Such abnormalities include anteriorly displaced papillary muscles, anomalous insertion of the chordae, and elongation of mitral leaflets.1,2 Mitral valve elongation can cause left ventricular outflow tract obstruction due to systolic anterior motion of the mitral valve leaflets even with only mild left ventricular hypertrophy (Figure 5).3 In this case, obstruction only developed with significant exertion. Symptoms of systolic anterior motion include syncope or presyncope, exertional dyspnea, and angina.Download figureDownload PowerPointFigure 5. Detailed illustration of the movement of the mitral valve leaflets during ventricular systole.Left, Early systole. Upper right, Late systole at rest. Mitral valve leaflets do not cause significant obstruction of the outflow tract. Lower right, Afterload reduction and increased cardiac contractility cause mitral valve leaflets to be swept toward the anterior septum, obstructing outflow during late systole. Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.Here, we demonstrate the importance of the mitral valve in obstructing the left ventricular outflow tract, even in the absence of significant septal hypertrophy. Provocative maneuvers on physical exam can elicit essential clues to establishing a diagnosis.DisclosuresNone.FootnotesThe Data Supplement is available at https://www.ahajournals.org/doi/suppl/10.1161/CIRCIMAGING.119.009992.Rick A. Nishimura, MD, Department of Cardiovascular Diseases, Mayo Clinic, 200 1st St SW, Rochester, MN 55905. Email nishimura.[email protected]eduReferences1. Klues HG, Maron BJ, Dollar AL, Roberts WC. Diversity of structural mitral valve alterations in hypertrophic cardiomyopathy.Circulation. 1992; 85:1651–1660. doi: 10.1161/01.cir.85.5.1651LinkGoogle Scholar2. Klues HG, Proschan MA, Dollar AL, Spirito P, Roberts WC, Maron BJ. Echocardiographic assessment of mitral valve size in obstructive hypertrophic cardiomyopathy. Anatomic validation from mitral valve specimen.Circulation. 1993; 88:548–555. doi: 10.1161/01.cir.88.2.548LinkGoogle Scholar3. Sherrid MV, Balaram S, Kim B, Axel L, Swistel DG. The mitral valve in obstructive hypertrophic cardiomyopathy: a test in context.J Am Coll Cardiol. 2016; 67:1846–1858. doi: 10.1016/j.jacc.2016.01.071CrossrefMedlineGoogle Scholar Previous Back to top Next FiguresReferencesRelatedDetails April 2020Vol 13, Issue 4 Advertisement Article InformationMetrics © 2020 American Heart Association, Inc.https://doi.org/10.1161/CIRCIMAGING.119.009992PMID: 32208734 Originally publishedMarch 25, 2020 Keywordssyncopesystolic murmursechocardiographymiddle agedmitral valvecardiomyopathystress testhypertrophicPDF download Advertisement SubjectsEchocardiographyHypertrophyValvular Heart Disease