Coronary Artery Anatomy and Apical Sparing in Apical Ballooning Syndrome: Implications for Diagnosis and Aetiology

Background

Apical ballooning syndrome (ABS) is characterised by transient regional systolic dysfunction involving the left ventricular apex and mid-myocardial segments. The absence of obstructive coronary disease is required in some diagnostic criteria. Some investigators have suggested that a long “wrap-around” left anterior descending (LAD) artery may explain the pattern of regional wall motion abnormalities.

Methods and results

We reviewed the coronary angiograms and ventriculograms findings in a prospective ABS cohort of 46 patients (mean age 63±13, female 96%). Normal smooth coronary arteries were observed in 54%, with 30% having minor irregularities. Moderate or severe coronary artery lesions were identified in 7 (15%) patients, including 4 with moderate LAD disease. The extent of the LAD artery around the left ventricular apex to the diaphragmatic surface of the heart was scored. This score was compared to 60 consecutive gender-matched control patients without ABS and no observed difference between the two groups (p=0.62). 42% had sparing of LV apical akinesis which was independent of the LAD extent.

Conclusion

Moderate or severe coronary artery stenosis may co-exist in a small proportion of patients with ABS. Exclusion of these patients will underestimate the true incidence of ABS. The prevalence of “wrap-around” LAD is similar in ABS and non-ABS patients. Apical sparing in ABS is more consistent with aetiological hypotheses implicating LV stunning due to acutely elevated LV wall stress, rather than single or multi-vessel coronary spasm.

Keywords: Apical ballooning syndrome, Tako-tsubo cardiomyopathy, Coronary spasm, Plaque rupture, Coronary atherosclerosis, Pathophysiology