Clinical introduction

A middle-aged patient with previous stent to the left circumflex artery (LCx) 12 months before suffering from angina, now presented with acute-onset severe retrosternal chest pain with an ECG showing ST-elevation in the precordial leads (see online supplementary figure S1). He underwent emergency coronary angiography, which showed normal flow in all arteries and a patent LCx stent. The left anterior descending artery (LAD) contained a hazy filling defect in the mid vessel (figure 1A). Following administration of heparin, the filling defect in the mid-LAD resolved (figure 1B). The left ventriculogram showed severe systolic dysfunction involving the mid and apical segments (see online supplementary video 1). This was normal on the previous catheterisation.