Diagnostic testing in takotsubo syndrome

Abstract

At onset, takotsubo syndrome (TTS) resembles the clinical picture of an acute coronary syndrome. The most frequent electrocardiographic findings are ST-segment elevation, T-wave inversion, and Q waves. The detection of ST-segment depression in lead aVR is associated with high specificity with TTS and can be useful for early suspicion. Although increased serum troponin levels are reported in about 90% of patients, the concentrations of troponin and other cardiac necrosis enzymes are usually lower in TTS than in acute myocardial infarction. Transthoracic echocardiography is the first-line non-invasive imaging modality in the acute phase showing a depressed left ventricular (LV) ejection fraction, which recovers within few days or weeks. LV wall motion abnormalities extend beyond the territory of distribution of a single coronary artery and involve symmetrically the LV walls (‘circumferential pattern’). Echocardiography also provides additional information regarding the presence of reversible significant mitral regurgitation, LV outflow tract obstruction, right ventricular involvement, and intraventricular thrombi. Coronary angiography is the cornerstone of diagnosis since TTS is characterized by the absence of atherothrombotic lesions of the epicardial coronary arteries. Coronary computed tomography angiography is an alternative to coronary angiography only in stable and pain-free patients showing the typical features of TTS, especially if coronary angiography is not readily available. Cardiac magnetic resonance is useful in patients with poor acoustic windows or with suspected TTS and incomplete LV myocardial function recovery during follow-up, helping to exclude a different aetiology. Nuclear imaging tests can be performed for prognostic purposes during the acute and subacute phase.