| Objective:To observe the variation of contractile synchrony in patients with different stages of heart failure by echocardiography and equilibrium radionulide angiography (ERNA) measurement; To analyze the various factors that affect contractile synchrony; To compare the advantages and disadvantages of the two kinds of measuring methods.Methods:The experimental group:A total of 206 patients with chronic heart failure patients were enrolled in our study as the experimental group (including 147 males and 59 females, and the age ranged from 18-85 year-old), while the control group was made up of 30 cases. The experimental group was divided into small group with high incidence of heart failure risk factors, small group with organic heart disease, small group with symptoms of heart failure, and small group with refractory heart failure, which were named A. B, C, D group respectively. Comparison of the interventricular and intraventricular synchronization indicators measured both by echocardiography and ERNA were made between the control group and A to D small groups respectively.Interventricular synchronization index:Interventricular mechanical delay (IVMD):It refers to the absolute difference between the pre-ejection time of aortic artery and that of the pulmonary artery measured by pulse Doppler spectrum. Interventricular contractile delay (â…£CD):It defined as the absolute difference of the dual-chamber phase shift calculated using the ERNA.Intraventricular synchronization index:Standard deviation (Ts-SD) of contraction peak time:It refers to the application of tissue Doppler imaging(TDI) to measure and calculate the mean value of contraction peak time of each segment by using the current prevailing 12-segment analysis method (including six basal segments and six middle segments), then calculate the standard deviation of the collecting data. Left ventricular phase shift width (LVPSW) and left ventricular phase standard deviation (LVPSD):LVPSW and LVPSD were both calculated by using ERNA method.Right ventricular phase shift width (RVPSW) and right ventricular phase standard deviation (RVPSD):RVPSW and RVPSD were both calculated by using ERNA method. Comparison of the following index including IVMD, LVCD, LVPSW, LVPSD and TS-SD was made between the control group and A to D small group in turn, and comparison of the same index was also made among A to D four groups; To analyze the relationship between cardiac resynchronization index (including FVMD, LVCD, LVPSW, LVPSD and TS-SD) and LVEF, LVEDD,the duration of QRS complex, age, gender and basic heart disease; thus fulfilling the comparison of the two measuring methods.Results:Interventricular synchronization:Interventricular contractile dyssynchrony began to emerge in the patients with chronic heart failure of group A, With the progressing of inter-stage, interventricular synchronization had a trend of gradually decreasing, see Table 2 and Table 3. Factors that affect interventricular synchronization:With the decreasing of LVEF, the enlarging of the LVEDD and the prolonging of the QRS duration, interventricular synchronization decreased. Partial correlation analysis suggested that interventricular synchronization was still related to LVEDD and the QRS duration, when all the other influencing factors were under control, thus to patients with chronic heart failure, LVEDD and the QRS duration are independent influencing factors to interventricular synchronization. The interventricular synchronization is not related to gender, age and basic heart disease of the subjects.Intraventricular synchronization:Intraventricular contractile dyssynchrony began to emerge in the patients with chronic heart failure of group A, and there was a strong relationship between intraventricular synchronization and inter-stage progress of heart failure. With the progressing of inter-stage, intraventricular synchronization decreased, see Table 4 and Table 5. Factors that affect imtraventricular synchronization:(1)With the decreasing of LVEF, the intraventricular synchronization began to decrease. The decrease of intraventricular synchronization began to slow down when EF decreased from 35% to 20%, see Table 6. Partial correlation analysis suggested that intraventricular synchronization was still related to LVEF when all the other influencing factors were under control, thus to patients with chronic heart failure, LVEF is one of the independent influencing factors to intraventricular synchronization. With the enlarging of LVEDD, the intraventricular synchronization of the patients with chronic heart failure decreased. Partial correlation analysis suggested that intraventricular synchronization was still related to LVEDD when all the other influencing factors were under control, thus to patients with chronic heart failure, LVEDD is also one of the independent influencing factors to intraventricular synchronization. On the other hand, with the prolonging of QRS duration, the intraventricular synchronization decreased, too. Partial correlation analysis showed that intraventricular synchronization was still related to QRS duration when all the other influencing factors were under control, thus to patients with chronic heart failure, QRS duration is another independent influencing factor to intraventricular synchronization. The incidence of dyssynchrony of wide QRS group was higher than that of normal QRS group, see details in Table 9. Intraventricular synchronization is not related to gender, age and basic heart disease.The RV synchrony of the ischemic cardiomyopathy group is worse than that of the dilated cardiomyopathy group, see Table 12.The collecting data showed that LVEF measured by echocardiography was higher than that measured by ERNA, while the repeatability of ERNA was better than that of the echocardiography on interventricular and intraventricular synchrony measuring.Conclusion:1.Interventricular and intraventricular dyssynchrony began to emerge in a very early stage of chronic heart failure, and there was a strong relationship between intraventricular synchronization and inter-stage progress of heart failure. With the progressing of inter-stage, intraventricular synchronization deteriorated. Patients with early stage of chronic heart failure might benefit a lot from individual screening of ventricular contractile dyssynchrony by either echocardiograpy or radionuclide method, to whom we could interfere with medication therapy at the early stage of the disease.2. With the any one of the following conditions (including decreasing of LVEF, the enlarging of LVEDD and the prolonging of the QRS duration), the interventricular synchronization of the patients with chronic heart failure deteriorated. LVEDD and the QRS duration are independent influencing factors to interventricular synchronization. With the decreasing of LVEF, the decrease of intraventricular synchronization began to slow down, which suggested that the further decrease of myocardial contraction could partially counteract the decrease of myocardial contraction synchrony. With the enlarging of the LVEDD, the intraventricular synchronization of the patients with chronic heart failure deteriorated, so LVEDD is one of the independent influencing factors to intraventricular synchronization. With the prolonging of QRS duration, the intraventricular synchronization deteriorated, which suggested that QRS duration is also one of the independent influencing factors to intraventricular synchronization.3.ERNA had superiority over TDI in evaluating repeatability of cardial contractile synchrony, so the use of the former measuring method in evaluating cardial contractile synchrony before CRT can have promising results. |
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