Macroscopic T-wave alternans preceding torsades de pointes in Takotsubo cardiomyopathy

A man in his 60s presented with acute heart failure and striking repolarization abnormalities on admission ECG, including deep diffuse T-wave inversion, marked QT prolongation, and macroscopic T-wave alternans. Coronary angiography revealed unobstructed vessels, and cardiac magnetic-resonance imaging demonstrated mid-to-apical myocardial edema, confirming Takotsubo cardiomyopathy. Continuous Holter monitoring captured progressive alternans followed by a pause-dependent short-long-short sequence and an R-on-T premature ventricular complex triggering torsades de pointes. This case illustrates how catecholamine surge and acute myocardialedema create calcium-handling impairment, ionic instability, and temporal-spatial repolarization dispersion, forming a substrate for malignant arrhythmias. Early recognition of this ECG triad is essential, as the initial vulnerable phase carries the greatest torsades risk. Optimal management centers on continuous monitoring, high-normal potassium and magnesium levels, strict avoidance of QT-prolonging or adrenergic agents, and prompt intravenous magnesium sulfate as first-line therapy when torsades occurs.