Myocardial Perfusion and Fatty Acid Metabolism in Patients with Tako-tsubo-like Left Ventricular Dysfunction

Objectives: We sought to assess myocardial perfusion and metabolism in patients with peculiar transient asynergy, which consisted of basal normokinesia and apical akinesia of the left ventricle (LV) at the same time.

Background: This asynergy has been widely called "tako-tsubo-like LV dysfunction" in Japan, but little is known about its pathophysiology.

Methods: We performed rest tallium-201 ((201)Tl) and iodine-123-beta-methyl-p-iodophenyl penta-decanoic acid ((123)I-BMIPP) dual-isotope myocardial single-photon emission computed tomography (SPECT) in 14 patients with tako-tsubo-like LV dysfunction. The LV was divided into 17 segments, and each segment was graded with scores between normal uptake (0) and defect (4). We also measured the Thrombolysis in Myocardial Infarction trial (TIMI) frame count in 28 patients and 20 control subjects.

Results: Early SPECT (5 +/- 3 days) revealed that the total defect score value with BMIPP was significantly higher than reduced uptake with (201)Tl (p < 0.01). Reduced uptake of BMIPP was observed in parallel with an apical akinetic region and usually involved uptake of (201)Tl. This discrepancy improved gradually during the follow-up period (29 +/- 6 days) (p = 0.36). Compared with control subjects, patients had a TIMI frame count that was significantly higher in all coronary arteries immediately after onset. This higher TIMI frame count decreased but was sustained even after resolution of tako-tsubo-like LV dysfunction.

Conclusions: Our data suggest that myocardial fatty acid metabolism is more severely impaired than myocardial perfusion, in parallel with an apical akinetic region during the early phase, and that impaired multivessel coronary microcirculation is involved, at least in part, in tako-tsubo-like LV dysfunction.