Are some false-positive stress echocardiograms a forme fruste variety of apical ballooning syndrome?

The mechanisms for abnormal stress echocardiograms (SEs) in patients with normal coronary arteries have not been clearly elucidated. We hypothesized that in some patients, this phenomenon may represent a forme fruste of apical ballooning syndrome (ABS). The aim of the study was to evaluate the characteristics of patients with strongly false-positive SEs and determine whether there were similarities to ABS. Thirty-one patients from the Mayo Clinic stress echocardiography database who had normal function at rest, extensive regional wall motion abnormalities in association with an abnormal response of left ventricular end-systolic cavity size at peak stress, and angiographically normal coronary arteries were evaluated. Eighty-four percent were women with a mean age of 61 +/- 12 years, 6% had a positive stress electrocardiogram, and only 26% had a hypertensive response to stress. In 81%, left ventricular ejection fraction decreased with stress and 97% developed new regional wall motion abnormalities in > or =4 segments. Peak wall motion score index was 1.65 +/- 0.39. Midventricular (100%) and apical (87%) segments were most often involved with relative sparing of the basal segments (77%; p = 0.01). There were no deaths during follow-up (2.3 +/- 0.7 years). In conclusion, the major findings of this study were that strongly false-positive SEs occurred predominantly in postmenopausal women, and frequently involved the apical and mid-left ventricular segments, features that were similar to ABS. Data were consistent with the hypothesis that some false-positive SEs may represent a forme fruste of ABS.