Study On Relationship Between QRS Duration And Ventricular Mechanical Synchrony Movement In Patients With Dilated Cardiomyopathy

Research Background:The etiology of dilated cardiomyopathy (DCM) is unclear, so there is no thoroughcure method now. In the early phase of the disease, basing on the treatment of β receptorblockers and angiotensin converting enzyme inhibitors (ACEI), delay the progression of thedisease and improve the prognosis of the patients; But with progressive deterioration, onthe stage of congestive heart failure, the basic medical treatment fails to correct, andpatients’ symptoms of heart failure become repeated and gradually worsened, eventuallypatient can be refractory heart failure, arrhythmia, thrombosis and embolism and suddencardiac death with high fatality close to50%in five years. Study confirms that Cardiacresynchronization therapy (CRT) is an effective non-drug treatment to the patients who aredilated cardiomyopathy with heart failure and ventricular mechanical contraction loss ofsynchronism at present. However, even if we are according to the inclusion criteriasuggested by CRT guide, there are still20-30%patients with poor response to CRT or evenno response. Thus, Lots of scholars are skeptical of the CRT inclusion criteria. So, ifelectrical activity of the ventricular depolarization’s QRS wave time limit can replaceventricular contraction mechanical synchronicity index as the main inclusion criteria ofCRT, and whether we can explore a diagnostic technique that independent of the QRS toevaluate ventricular contraction mechanical synchronicity become a research hotspot.Objective：A research on the relationship between the QRS wave duration of idiopathic dilatedcardiomyopathy patient and the synchronicity of left ventricular mechanical contractionusing real-time three-dimensional echocardiography，RT-3DE.Method：From September,2012to June,2013,63patients diagnosed with DCM in Cardiologyof Southwest Hospital, were divided into the following groups according to QRS duration:①A1group, QRS <120ms (n=36), Male22cases, female14cases, average age(52.17±13.30);②A2group,120ms≤QRS <150ms (n=17),12males and5females,average age (58.71±9.43);③A3group, QRS≥150ms (n=10),9males,1female,average age (54.10±10.57). As left ventricular arriving at segments6,12,16, the standarddeviation and the maximum difference of minimum systolic volume time are acquired byRT-3DE, and standardized value is also obtained. Assuming Tmsv16-SD%as Systolicdyssynchrony index，SDI,5.12%is seen as a cutoff point value to judge whether leftventricular systolic is synchronized. SDI＜5.12%deemed ventricular mechanical systolicsynchrony, SDI>5.12%deemed ventricular mechanical systolic dyssynchrony.Results：①The respective SDI of A1, A2, A3group is (6.26±4.08),(8.53±4.12),(10.82±6.24). There is significant difference between group A1and group A3(P <0.05). Among A1and A2, A2and A3, with the broadening of QRS wave duration, SDI is increased gradually(P>0.05);②At group A1, A2, A3, there is no correlation (P>0.05) among SDI and QRSduration, LVEDV, LVEF, and LVESV.Conclusion：This study showed that the ventricular systolic dyssynchrony detection rate amongDCM patients with wide QRS wave is higher than those with narrow QRS wave. There isno correlation between QRS wave duration and left ventricular systolic synchronicity.