Assessment of Takotsubo (ampulla) cardiomyopathy using 99mTc-tetrofosmin myocardial SPECT--comparison with acute coronary syndrome.

Abstract

We assessed Takotsubo (ampulla) cardiomyopathy compared with acute coronary syndrome (ACS) using two-dimensional echocardiography and 99mTc-tetrofosmin myocardial SPECT. We examined 10 patients with Takotsubo cardiomyopathy and 16 with ACS at the time of emergency admission (acute phase), at three to nine days after the attack (subacute phase) and at one month after the attack (chronic phase). The left ventricle was divided into nine regions on echocardiograms and SPECT images, and the degree of abnormalities in each region was scored in five grades from normal (0) to severely abnormal (4). Coronary angiography revealed total or subtotal occlusion in patients with ACS but no stenotic legions in those with Takotsubo cardiomyopathy. The amount of ST segment elevation (mm) was 7.9 +/- 3.4 in patients with Takotsubo cardiomyopathy and 7.3 +/- 3.7 in those with ACS (N.S.). Abnormal wall motion scores on echocardiograms were 13.8 +/- 4.4, 4.4 +/- 3.8 and 1.8 +/- 2.3 during the acute, subacute and chronic phases in patients with Takotsubo cardiomyopathy, and 13.9 +/- 4.0, 11.7 +/- 3.7, 7.6 +/- 4.2, respectively in patients with ACS. The value of MB fraction of creatine phosphokinase (IU/l) was 34 +/- 23 in patients with Takotsubo cardiomyopathy and 326 +/- 98 in those with ACS (p < 0.001). Abnormal myocardial perfusion scores on 99mTc-tetrofosmin myocardial SPECT were 11.4 +/- 3.2, 3.2 +/- 3.3 and 0.7 +/- 1.1 during the acute, subacute and chronic phases respectively, in patients with Takotsubo cardiomyopathy, and 15.8 +/- 4.1, 13.5 +/- 4.4, 8.2 +/- 4.4, respectively, in those with ACS. The numbers of myocardial segments that did not uptake 99mTc-tetrofosmin during the acute phase were 0.5 +/- 0.8 and 3.6 +/- 2.8 in patients with Takotsubo cardiomyopathy and ACS, respectively. Impaired coronary microcirculation might be a causative mechanism of Takotsubo cardiomyopathy.