Madhav Menon

Spectrum and Significance of Electrocardiographic Patterns, Troponin Levels, and Thrombolysis in Myocardial Infarction Frame Count in Patients With Stress (Tako-tsubo) Cardiomyopathy and Comparison to Those in Patients With ST-Elevation Anterior Wall Myocardial Infarction

Stress (takotsubo) cardiomyopathy (SC) is a recently recognized syndrome with clinical and electrocardiographic (ECG) presentation resembling ST elevation anterior myocardial infarction. As experience with this condition has evolved, a more diverse spectrum of 12-lead ECG patterns has emerged that may affect differential diagnosis. Fifty-nine consecutive patients with SC were prospectively identified at a large community-based cardiology practice. All were women aged 32 to 90 years (mean 66+/-13) with acute chest pain triggered by emotional or physical incidents and with akinesia of the mid-distal left ventricle; each patient recovered and was discharged within a median of 4 days. On electrocardiography, anterior ST elevation was most common (33 [56%]), with magnitudes less than in controls with left anterior descending coronary artery occlusions (1.4+/-1.5 vs 2.4+/-2.2 mm, p<0.001), with considerable overlap. ECG findings in 26 other patients (44%) without ST elevation revealed diffuse T-wave inversion (10 [17%]) and healed anterior infarctions (6 [10%]) or were nonspecific (5 [8.5%]) or normal (5 [8.5%]). Troponin elevations occurred in 56 patients with SC (95%). The mean peak troponin T level was significantly lower in patients with SC (0.64+/-0.86 ng/ml) than in those with left anterior descending coronary artery occlusions (3.88+/-4.9 ng/ml) (p<0.0001). Patients with SC with or without ST elevation did not differ with respect to the ejection fraction (29+/-9% vs 34+/-9%, respectively, p=NS) or Thrombolysis In Myocardial Infarction (TIMI) frame counts. During recovery, diffuse T-wave inversion evolved in 49 patients with SC (83%). In conclusion, patients with SC present with diverse ECG findings, and no single pattern alone can reliably distinguish this condition from acute coronary syndromes. The diagnosis of SC requires heightened awareness of its unique clinical profile as well as coronary arteriography and left ventriculography.