Takotsubo cardiomyopathy following radioiodine therapy for toxic multinodular goitre.

We report on a 73-year-old man with a toxic multinodular goitre, which was treated with radioiodine therapy (I-131) without pretreatment with an antithyroid drug. Four weeks later he presented with rapidly progressive dyspnoea and a significant increase in free thyroxin. The electrocardiogram showed ST -segment elevation, and echocardiography demonstrated apical akinesia and a left ventricular ejection fraction of only 25%. However, direct coronary catheterisation showed no evidence of coronary artery disease. Left ventricular angiography showed apical ballooning consistent with the diagnosis of takotsubo cardiomyopathy. Following treatment of the cardiomyopathy and thyrotoxicosis, he experienced a complete recovery. To the best of our knowledge, this is the first report of a takotsubo cardiomyopathy associated with thyrotoxicosis resulting from radiation thyroiditis induced by radioiodine. Three other cases of takotsubo cardiomyopathy associated with Graves' disease have been described in literature.

Comparison of left ventricular function at rest and post-stress in patients with myocardial infarction: Evaluation with gated SPECT.

BACKGROUND: Quantitative electrocardiogram-gated single photon emission computed tomography (SPECT) myocardial imaging (QGS) is a means of providing functional information about the left ventricle and myocardial perfusion. However, the functional information derived 30 minutes post-stress may be different from the left ventricular (LV) function determined at rest. This study determined whether LV function post-stress would be different from LV function at rest in patients with an earlier myocardial infarction. METHODS AND RESULTS: LV perfusion and ejection fraction (LVEF), were determined by means of both the rest and post-stress acquisition in 58 patients with an earlier myocardial infarction and in 23 patients with a low likelihood of coronary artery disease by using technetium-99m tetrofosmin and the QGS program. The interobserver and intraobserver variability of LVEF was excellent, within a margin of 2%. No significant differences in LVEF were observed between post-stress and rest in the 23 patients with a low likelihood of disease (DeltaLVEF, 0.04% +/- 3.2%, P = not significant). Conversely, the patients with an earlier myocardial infarction showed a significantly lower LVEF post-stress, compared with that at rest (DeltaLVEF, -1.9% +/- 4.2%, P =.002). In 33 patients (57%), the LVEF post-stress was 2% or more lower than the LVEF at rest. Furthermore, reversible ischemia, which was present in 16 patients (28%), did not interact with the DeltaLVEF post-stress, compared with the DeltaLVEF at rest (P = not significant). Parameters such as the stress modality (adenosine stress or exercise), the number of stenosed vessels, or the perfusion defect severity score did not influence the DeltaLVEF post-stress, compared with the DeltaLVEF at rest. CONCLUSIONS: In patients with an earlier myocardial infarction, LV function post-stress may not represent the true resting LV function. Consequently, this result justifies the stratification of patients before starting the gated SPECT study. In patients with an earlier myocardial infarction, the gated acquisition should be performed during the rest study.