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Review
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Korean J Med. 2006;71(1):276-276.
- Changes of intraventricular dyssynchrony with dobutamine can predict the response to medical therapy in patients with dilated cardiomyopathy
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., , , , , , , ,
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- Changes of intraventricular dyssynchrony with dobutamine can predict the response to medical therapy in patients with dilated cardiomyopathy
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, , , , , , , ,
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1Department of Internal Medicine, Hanyang University College of Medicine, Seoul; 2Department of Life Science, Postech Biotech Center, Pohang University of Science and Technology, Pohang, Korea
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- Abstract
- Background : It is well known that intraventricular dyssynchrony is prevalent and badly affects clinical outcome in patients with dilated
cardiomyopathy. The extent of intraventricular dyssynchrony may change with exercise or pharmacological stress as left ventricular (LV)
systolic function changes. However, the clinical significance of these changes is not clear. We investigated the impact of dyssynchrony
changes with dobutamine infusion on the prognosis after medical therapy in these patients. Methods : Thirty six patients (20 men, age:
57¡¾13 years) with the diagnosis of idiopathic dilated cardiomyopathy were enrolled in the study. Ischemic heart disease was excluded
by coronary angiography or myocardial SPECT. Comprehensive echocardiographic examination was performed at baseline and repeated
6 months after intensive medical therapy. Time from R wave on ECG to peak systolic velocity (Ts) was measured in 12 segments of
LV using tissue synchronization imaging. The standard deviation of Ts (Ts-SD) was an indicator of systolic dyssynchrony. The
measurements were repeated with dobutamine infusion at 10mcg/kg/min. Results : After 6 months of medical therapy, LV ejection
fraction (EF) (34.6¡¾10.7 vs 40.7¡¾11.3%, p<0.05) and Ts-SD (44¡¾17 vs 34¡¾18 msec, p<0.05) improved significantly. With dobutamine
infusion, LVEF and Ts-SD improved by more than 5% in 47 % and 53% of patients, respectively. Dobutamine induced improvement of
Ts-SD were significantly related with dobutamine induced increase of LVEF (r=0.566, p<0.05). Improvement of Ts-SD with dobutamine
was significantly correlated with improvement of LVEF at 6 month follow up (r=0.448, p<0.05). Patients who showed Ts-SD improvement
with dobutamine by more than 5% had greater increase of LVEF at 6 months follow-up than those who did not (8.5 vs 0.5%, p=0.039).
Conclusion
: Intraventricular dyssynchrony was significantly improved with dobutamine in substantial proportion of patients with dilated
cardiomyopathy and this improvement was closely associated with the favorable response to medical therapy. Dobutamine induced
changes of dyssynchrony may need to be in consideration for selecting candidates for cardiac resynchronization therapy.
Keywords :
