Out-of-Hospital Cardiac Arrest As the Initial Presentation of Takotsubo Cardiomyopathy in the Presence of Severe Myocardial Bridge: A Diagnostic Challenge.

Takotsubo cardiomyopathy (TC) is characterized by transient, reversible systolic dysfunction in the absence of angiographic evidence of obstructive coronary artery disease (CAD). TC often mimics acute coronary syndrome (ACS) and is frequently precipitated by emotional or physical stress. In this report, a 45-year-old woman experienced out-of-hospital cardiac arrest (OHCA) due to ventricular fibrillation. Coronary angiography (CAG) identified severe myocardial bridging (MB), complicating the diagnostic process. Physiological assessment with instantaneous wave-free ratio (iFR) and fractional flow reserve (FFR) revealed no significant flow limitation attributable to MB. Transthoracic echocardiogram (TTE) demonstrated apical ballooning with reduced ejection fraction, which improved rapidly. These findings supported the diagnosis of TC. This case demonstrates that cardiac arrest (CA) can be the initial manifestation of TC. Clinicians should consider TC in patients presenting with CA or chest pain, particularly when reversible left ventricular dysfunction with apical ballooning is present. When MB coexists with TC, multimodality imaging and physiological assessment are critical for accurate diagnosis.