Abstract 14124: A Marked Increase in Myocardial Oxidative Stress Associated With Sympathetic Hyperactivity is Related to Transient Myocardial Dysfunction in Patients With Takotsubo Cardiomyopathy
Introduction: Sympathetic hyperactivity is considered as one of the most likely pathogenic mechanism in takotsubo cardiomyopathy (TC). However, little is known about the relationship between sympathetic hyperactivity and myocardial oxidative stress (OS).
Hypothesis: We hypothesized that cardiac sympathetic hyperactivity was associated with cardiac myocardial OS, and OS related to transient myocardial dysfunction in patients with TC compared with acute anteroseptal myocardial infarction (AMI).
Methods: In 8 TC patients and 8 AMI patients (NYHA 3), ECG, echocardiography, cardiac catheterization and serial measurements of plasma catecholamines, urinary (U) 8-hydroxy-2’-deoxyguanosine (8-OHdG) as a marker of OS and plasma CPK were performed for two weeks from onset.
Results: Blood sampling from coronary sinus (CS) and aorta (Ao) at 1st day showed that norepinephrine (NE) levels and 8-OHdG level in CS were significantly higher than those in Ao and peripheral blood, indicating that an increase in myocardial OS was associated with cardiac sympathetic hyperactivity. NE levels in peripheral blood were peaked out at 1st day and 2-times higher in TC than in AMI within a week, while the max CPK value in TC was significantly lower than that in AMI. Dual scintigraphy of 201Tl and 123I-meta-iodobenzylguanidine was performed at 7th day showed that cardiac sympathetic nervous injury was much larger than myocardial perfusion damage in all TC patients. U-8OHdG level (ng/mg Cr; normal range:<10.0) in TC was elevated in parallel with the profile of plasma NE level (1st day: 65.6±24.5, 4th day: 19.1±8.3, 7th day: 16.4±9.1), while it was decreased to almost normal range after percutaneous coronary intervention for left anterior descending artery in AMI (1st day: 24.3±13.8, 4th day: 9.8±3.4, 7th day: 12.3±2.7). Interestingly, difference in serum 8-OHdG levels (CS vs Ao) in TC increased proportionally with wall motion score (WMS) as an index of LV dysfunction (R=0.93, p<0.001), while difference in serum NA levels (CA vs Ao) in TC did not. U-8OHdG level in TC was positively correlated with WMS at each day (1st day, 7th day).
Conclusions: These findings suggest that myocardial OS induced by cardiac sympathetic hyperactivity may play a critical role in transient LV dysfunction in TC.
Author Disclosures: T. Nanno: None. S. Kobayashi: None. S. Oda: None. H. Ishiguchi: None. T. Myoren: None. Y. Miyazaki: None. T. Suetomi: None. M. Ono: None. M. Mochizuki: None. T. Oda: None. S. Okuda: None. J. Yamada: None. T. Okamura: None. M. Yano: None.
- © 2015 by American Heart Association, Inc.