The apical nipple sign: a useful tool for discriminating between anterior infarction and transient left ventricular ballooning syndrome

Abstract
Even after coronary angiography, transient left ventricular ballooning syndrome (TLVBS) can be misdiagnosed as ST-elevation myocardial infarction (STEMI) caused by transient thrombotic occlusion of the left anterior descending artery, as the appearance of the left ventricular angiograms is often very similar. As prognosis and antithrombotic treatment of these two conditions differ widely, it is desirable to make a correct diagnosis as early as possible. Between January 1998 and August 2012, we identified 145 patients diagnosed with TLVBS in a single tertiary hospital, based on the Mayo criteria and (near) normalization of left ventricular function over weeks. For 119 of these patients, coronary and left ventricular angiograms were available for detailed study. In 27 (22.7%) patients, mid-ventricular ballooning was observed, with preserved contractility of the apex, while in 92 (77.3%) typical apical ballooning was seen, with extensive akinesis of the apex. In 28 of the patients with typical apical ballooning (30.4%), we observed the presence of a very small zone with preserved contractility in the most apical portion of the left ventricle. We coined this phenomenon ‘apical nipple sign’. For comparison, we reviewed the left ventricular angiograms of 405 patients who had been treated for anterior STEMI by emergency percutaneous intervention on the left anterior descending artery in our hospital between February 2007 and October 2012. On careful review, the apical nipple sign was not seen in any of these. While discrimination between TLVBS and anterior STEMI is warranted as early as possible after admission, this is very difficult, especially in the majority of cases presenting with the classical apical ballooning phenotype. By observing the herein-described apical nipple sign, the attending physician can make the diagnosis of TLVBS with virtual certainty in almost one-third of cases.