Study Of Differential Of Left Ventricular Dyssynchrony Parameters From Stress And Rest Gated Myocardial Perfusion SPECT Imaging

Background Congestive heart failure is the end stage of all kinds of cardiovascular disease,curative effect of medical therapy is not good.Cardiac Resynchronization Therapy(CRT) was described as a landmark breakthrough for the treatment of congestive heart failure. Many clinical trials supports the use of CRT to improve exercise capacity, quality of life,and LVEF and to reduce the combined risk of death of any cause or unplanned hospital admission for a major cardiovascular event. CRT is now recommended in patients with HF(NYHA class Ⅱ to Ⅳ),severe systolic dysfunction(eg,left ventricular ejection≤35%) and intraventricular conduction delay(eg,QRS≥120ms).But approximately20%-30%of the patients who received CRT do not response. The main reason for CRT no response may be that the patients with electrical dyssynchrony may not have mechanical dyssynchrony as well. How to measure LV mechanical dyssynchrony accurately is the key for CRT patients selection and improving CRT response. Myocardial perfusion SPECT (MPS) is most widely used for the diagnosis of coronary heart disease. Recently,phase analysis (PA) has developed for assessment of LV dyssynchrony from gated myocardial persusion SPECT (G-MPS),it has high accuracy and repeatability. Up to now,LV dyssynchrony parameters were from resting G-MPS in a lot of research,is there significant difference between LV dyssynchrony parameters from resting G-MPS and from stress G-MPS is uncertain.Objective:To determine whether LV dyssynchrony parameters measured by SyncTool from stress G-MPS significantly differed from those from rest G-MPS.Methods:Consecutive60normal subjects,40patients with ischemia,and40patients with LV dysfunction were enrolled in this study. Half of them underwent exercise stress/rest G-MPS, another half underwent adenosine stress/rest G-MPS. The short axis data from rest and stress were then submitted to SyncTool to measure phase standard deviation(PSD),phase histogram(PHB).Results There were no significant difference for LV dyssynchrony parameters(PSD、PHB)between stress(exercise or adenosine) G-MPS and rest G-MPS in three grounps(P>0.05). In the subgroup analysis of patients with LV dysfunction, the rest and stress PSD and the rest and stress PHB, respectively(P>0.05),were similar in the two subgroups(ischemic cardiomyopathy and dialated cardiomyopathy).The change(stress-rest) in PSD and PHB in each patient with LV dysfunction were evaluated by one-sample Z test, none of value of Z go beyond±1.65.Conclusion:LV dyssynchrony parameters measured by Phase analysis from stress G-MPS have the same clinical value with that from rest G-MPS.