Abstract 12561: Analysis of Impaired Myocardial Perfusion Using Cardiac Magnetic Resonance Imaging in Patients with Stress (Takotsubo) Cardiomyopathy
Background: Stress cardiomyopathy (SC) mimics ST elevation myocardial infarction without substantial angiographic stenosis. Coronary microvascular dysfunction has been proposed to be a possible mechanism of SC. However, demonstration of microvascular dysfunction by imaging modalities has been considered difficult. The aim of this study was to assess dynamic myocardial perfusion quantitatively by cardiovascular magnetic resonance imaging (CMR).
Methods: CMR was performed on a 1.5-T clinical scanner (Magnetom Symphony, Siemens) within 3 days of coronary angiographic and left ventriculographic diagnosis of SC. Cine imaging was performed to detect the impaired wall motion site. Dynamic perfusion imaging was performed in one long axis and three short axis views (base, mid-ventricle and apex) after intravenous bolus injection of 0.2 mmol/kg gadolinium-based contrast agent. For quantitative analysis, we set regions of interest (ROI) at the sites of normal and impaired wall motion at the base, mid-ventricle and apex. Time-intensity curve was drawn, peak di/dt was calculated and the means were compared statistically.
Results: Between July 2005 and July 2011, 34 patients (94.1% females; mean age 71.3 ± 8.4 years) were studied. Of these patients, 27 had apical ballooning (classical type) and 7 had mid-ventricular ballooning (variant type). In the classical type, peak di/dt was significantly lower at the apex than at the base and mid-ventricle (apex vs base: 5.76 vs 7.29, p<0.001; vs mid: 6.68, p<0.001). In the variant type, peak di/dt was significantly lower at the mid-ventricle than at the base and apex (mid vs base: 7.59 vs 8.69, p=0.024; vs apex: 8.6, p=0.007). Thirteen patients with classical type underwent follow-up CMR (median follow-up period 266 days from attack), which revealed recovered wall motion. All patients showed normalization of perfusion delay and peak di/dt (apex vs base: 6.68 vs 7.1, p=0.15; vs mid: 7.21, p=0.11). These results suggest that coronary microvascular dysfunction is related to wall motion abnormalities, and improvement of coronary microvascular dysfunction parallels recovery of wall motion.
Conclusion: Dynamic perfusion CMR is useful for quantitative assessment of microvascular dysfunction in SC.
- © 2011 by American Heart Association, Inc.