title: Cardiogenic shock accompanied by dynamic left ventricular outflow tract obstruction and myocardial bridging after transient complete atrioventricular block mimicking ST-elevation myocardial infarction: a case report.
abstract: BACKGROUND
  Dynamic left ventricular outflow tract obstruction with or without mitral regurgitation is typically observed in hypertrophic cardiomyopathy, but is also occasionally seen without left ventricular hypertrophy. In this report, we present a case of cardiogenic shock that mimics ST-elevation myocardial infarction, due to dynamic left ventricular outflow tract obstruction with transient mitral regurgitation and myocardial bridging after transient complete atrioventricular block.
  
  
  METHODS
  A 65-year-old man with hypertension presented himself at the emergency department with syncope after chest pain. His initial electrocardiography showed inferior ST elevation with profound precordial ST depression and transient complete atrioventricular block. Due to sustained hypotension, an intra-aortic balloon pump was applied. His coronary angiography revealed almost normal right coronary artery and left circumflex artery and only a severe myocardial bridge in the mid-segment of his left anterior descending artery. Instead, severe mitral regurgitation was found without regional wall motion abnormality both in the left ventriculography and the portable echocardiography. However the severe mitral regurgitation completely disappeared in follow up echocardiography the day after. The pressure gradient across the left ventricular outflow tract was measured at 8.95 mmHg during the resting state, and was increased to 38.95 mmHg during the Valsalva state.
  
  
  CONCLUSIONS
  The patient presented with a case of cardiogenic shock that mimicked ST-elevation myocardial infarction due to dynamic left ventricular outflow tract obstruction combined with myocardial bridging in the mid-left anterior descending artery.
authors.forename: Seonghui
authors.initials: S
authors.lastname: Kang
authors.forename: Sanghee
authors.initials: S
authors.lastname: An
authors.forename: Hyung Min
authors.initials: HM
authors.lastname: Yu
authors.forename: Jiwan
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea. shkim@kuh.ac.kr.
authors.forename: Sung Hea
authors.initials: SH
authors.lastname: Kim
authors.forename: Hyun-Joong
authors.initials: HJ
authors.lastname: Kim
authors.forename: Sang Man
authors.initials: SM
authors.lastname: Chung
mesh_terms: D000368:Aged; D054537:Atrioventricular Block / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D003937:Diagnosis, Differential; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D054084:Myocardial Bridging / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D009203:Myocardial Infarction / Q000175:diagnosis / Q000473:pathology; D012770:Shock, Cardiogenic / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D014463:Ultrasonography