Aims: To study coronary microvascular dysfunction as possible pathogenetic mechanism in Apical Ballooning Syndrome (ABS).
Methods and results: Fifteen ABS patients (all women, 68 +/- 14 years) underwent myocardial contrast echocardiography at baseline during adenosine infusion (140 microg/kg/min) and at 1-month follow-up and compared with a group of anterior ST-elevation myocardial infarction (STEMI) patients with similar clinical characteristics. Myocardial perfusion was assessed by contrast score index (CSI) and endocardial length of contrast defect (contrast defect length, CDL), whereas myocardial dysfunction by wall motion score index (WMSI), endocardial length of contractile dysfunction (wall motion defect length, WMDL), and LV ejection fraction (LVEF). At baseline, no difference in myocardial perfusion and dysfunction were present between the two groups. During adenosine challenge, while no changes were observed in STEMI group, in ABS patients CSI, CDL, WMSI, and WMDL significantly decreased compared with baseline (P < 0.001 vs. baseline for all parameters) and LVEF significantly increased (P = 0.01 vs. baseline). At 1-month follow-up, myocardial perfusion and dysfunction completely recovered in ABS patients (P < 0.001 vs. baseline for all parameters), whereas no significant changes were observed in STEMI group.
Conclusion: Our data strongly suggest that in ABS, irrespectively of its underlying aetiology, acute and reversible coronary microvascular vasoconstriction could represent a common pathophysiological mechanism.