Multi-modality imaging evaluation of recurrent Tako-tsubo syndrome in a patient with coronary artery fibromuscular dysplasia

Although its clinical manifestation often mimics that of an acute anterior wall myocardial infarction (MI), Takotsubo syndrome (TTS) was postulated to have completely different etiology, pathophysiology and prognosis [1, 2]. As more real-time cardiac imaging, particularly bedside echocardiography, are applied, TTS have been frequently identified in patients with co-existing coronary artery disease. Multi-modality imaging evaluation help characterize the discrepancy between myocardial injury and ventricular mechanic dysfunction during TTS and MI.

A 57 year-old woman presented with sudden onset chest pain/ventricular fibrillation after hearing of her brother’s death. The electrocardiography indicated “anterior wall ST segment elevation myocardial infarction”. Laboratory data was notable for cTnT 1.12 ng/mL. Coronary angiography ruled out obstructive lesion in the major coronary arteries, but revealed a tapering and long narrowing distal left anterior descending artery (LAD, Fig. 1a and b), which was consistent with angiographic feature of coronary artery fibromuscular dysplasia [3]. The ventriculography showed remarkable ventricular dilation, which affected much broader myocardium than the culprit vessel supplied (Fig. 1c, arrowheads). In a subsequent cardiac magnetic resonance (CMR) study, left ventricular (LV) remained dilated (Fig. 1d). Delayed contrast (gadolinium) image confirmed a localized mayocardial infarction in the inferoapical wall (Fig. 1e and f).

One week later, repeated transthoracic echocardiography (TTE) showed nearly normalized LV systolic function except for a residual apical hypokinesis (Fig. 1h–n) compared with original episode (Fig. 1g–m). Nine months later, when she was laid off, she developed recurrent chest pain and significant LV dilation, with different contractile pattern (Fig. 1i–o). With only supportive therapy, both her symptoms and LV dysfunction spontaneously improved quickly.

The present case illustrates a unique scenario, in which TTS occur recurrently in the heart with pre-existing localized myocardial infarction. In contrast to “gate-keeper” role of bedside echocardiography, advanced cardiac imaging has improved the tomographic visualization and our understanding on myocardial injury/metabolism in both TTS [4, 5] and MI [6]. During acute MI, psychological stress and/or physical pain can stimulate central/autonomic nervous systems, and increase bioavailability of cortisol and circulating catecholamines, which may affect the myocardium supported by both culprit and non-culprit coronary arteries.

In the presence of coronary artery disorder, is hypocontractile myocardium beyond the myocardial territory of the culprit coronary artery a coincidence, or a cause-and-effect? Also, its clinical significance remains unknown. Molecular research has revealed that TTS is mediated by a cardio-protective switching of epinephrine signaling transduction through the pleiotropic β₂-adrenergic receptors [7]. Whether the TTS during and/or after MI represents a universal physiologically adaptive response of a jeopardized heart warrants further investigation.

TTS occurs recurrently in a patient with pre-existing localized myocardial infarction caused by coronary artery fibromyscular dysplasia.