title: Non-invasive detection of tako-tsubo cardiomyopathy vs. acute anterior myocardial infarction by transthoracic Doppler echocardiography.
abstract: OBJECTIVE
  Typical tako-tsubo cardiomyopathy (TTC) mimics acute anterior myocardial infarction (AMI) and the differential diagnosis is challenging before coronary angiography (CA) is performed; it demonstrates reduced or absent antegrade flow in the left anterior descending artery (LAD) in AMI, whereas there is no such flow limiting in TTC. At the acute phase, we tested the usefulness of the distal LAD flow visualization by transthoracic Doppler echocardiography (TDE) to distinguish between these two diseases. For this purpose, we prospectively enrolled 28 consecutive patients with TTC (75 ± 10 years, 93% females) who were compared with 28 consecutive patients with AMI treated successfully by primary angioplasty (66 ± 12 years, 79% females). All the patients underwent the assessment of the distal LAD flow just before CA, using colour and pulsed-wave TDE. In addition, the symmetric involvement of wall motion abnormalities (WMAs) based on the extent of the disease far beyond one coronary territory in TTC was searched by TDE. Non-invasive coronary flow reserve (CFR) by TDE, in the distal LAD, was also performed within 1 day after admission.
  
  
  RESULTS
  Before CA, the distal LAD flow was visible in 38 of 56 cases (68%) in the whole population, in all cases with TTC and in 10 cases with AMI (36%). The sensitivity (Se) and specificity (Sp) of the LAD flow visualization for the diagnosis of TTC were 100 and 64%, respectively, with a diagnostic accuracy of 82%. In comparison, the pattern of WMA yielded a Se of 75% and Sp of 86%, and a diagnostic accuracy of 80%. With the combination of both tools, the Se and Sp to detect TTC were 75 and 96% respectively, with a diagnostic accuracy of 86%. After CA, the acute CFR was less severely impaired in the TTC group when compared with the AMI group (2.2 ± 0.5 vs. 1.7 ± 0.6, P < 0.01) despite a worse LV systolic dysfunction.
  
  
  CONCLUSIONS
  Non-invasive evaluation of the distal LAD flow could be helpful to differentiate TTC from AMI, and its combination with the pattern of WMA improved slightly its diagnostic accuracy. Furthermore, the acute CFR is less severely impaired in TTC compared with AMI despite poorer LV systolic dysfunction, suggesting that other mechanisms than direct microcirculatory damage are also involved in the pathogenesis of WMAs in TTC.
authors.affiliation: Department of Cardiology, Centre Hospitalier De Compiegne, 8 Rue Henri Adnot, Compiegne 60200, France. patrickmeimoun.md@gmail.com
authors.forename: Patrick
authors.initials: P
authors.lastname: Meimoun
authors.forename: Jerome
authors.initials: J
authors.lastname: Clerc
authors.forename: Charles
authors.initials: C
authors.lastname: Vincent
authors.forename: Florent
authors.initials: F
authors.lastname: Flahaut
authors.forename: Anne Laure
authors.initials: AL
authors.lastname: Germain
authors.forename: Frederic
authors.initials: F
authors.lastname: Elmkies
authors.forename: Hamdane
authors.initials: H
authors.lastname: Zemir
authors.forename: Anne
authors.initials: A
authors.lastname: Luycx-Bore
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D056988:Anterior Wall Myocardial Infarction / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000401:mortality; D015331:Cohort Studies; D017023:Coronary Angiography / Q000379:methods; D003326:Coronary Circulation / Q000502:physiology; D003937:Diagnosis, Differential; D004452:Echocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation; D011446:Prospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D012737:Sex Factors; D015996:Survival Rate; D054549:Takotsubo Cardiomyopathy / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000401:mortality; D014057:Tomography, X-Ray Computed / Q000379:methods