The Relationship Between Left Ventricular Function And Arrhythmia In Dilated Cardiomyopathy

Dilated cardiomyopathy(DCM) is an unknown disease and the most common categoriy in all the primarily myocardiopathies.Cardiac dilatation and arrhythmia and congestive cardiac failure are the major clinical manifestation of DCM. The majority of DCM have the clinical manifestation of heart failure and all kinds of arrhythmiaes repeatedly. The incidence rate of ventricular arrhythmia and sudden death that hazard all the people,s lives is also very high.At present incidence rate of DCM has a high trendency,but it has never valid prevention methord. The survival rate in five years of DCM inferior to 50%, which hazards all the people,s lives.The possible mechanic of all kinds of arrhythmias is as follows:The first,the decease of left ventricular function and the incease of left ventricular end -diastole pressure and the volume burden persistently rises.The incease of left intraventricular pressure and left ventricular enlargement lead to left ventricular tension increase .Then cardiac muscle cell be mechanically dragged that makes Purkinje fiber be over extended .It results in depolarization and conduction velocity stepping down ,which causes reentry.The second , cardiac muscle drag decurtates time limited of the phase-Ⅱ,Ⅲof action potential and effective refractory period ,and it enhances the spontaneous depolarization of phase-Ⅳ,then increases autorhythmicity. Otherwise,DCM accompanys with sympathetic nerve ending fibra being damaged and cardiac muscle nerves myelinolysis possibly,which leads to cardiac muscle be supersensitive to catecholamines.It causes cardiac dysrhythmia easily. In addition ,DCM results in various kinds of arrhythmia by changing cardiac muscle electrophysiological characteristics due to myocardial ischemia and cardiac muscle damaged generally. Sympathetic nerve excitation releases redundant catecholamine and cardiac muscle enhance responses to catecholamine, which increase cardiac muscle electrophysiological instability,and catecholamine produces direct toxic effect to cardiac muscle. The predominant clinical manifestation of DCM includes cardiac inadequacy and various kinds of ventricular arrhythmia. The relation of the two in genesis and development of DCM plays extremely significant effect for the choice of therapeutic regimen and clinical prognosis.Electrocardiogram(ECG) and heart color Doppler of 108 patients with DCM are analyzed systematically to study the relationship between left ventricular function and arrhythmia in DCM,and provid reference for early intervention and management.In 108 patients with DCM,who are diagnosed according to the standard of WHO ,there are 79 males and 29 females(2.72:1)and the average age is 46.There are 20 cases (18.5%) with abiogenesis premature ventricualr contraction ,and 17 cases (15.7%) with frequency premature ventricualr contraction,and 4 cases (3.7%) with paroxysm ventricular tachycardia.All the selected patients are graded according to the damaged degree of heart function of NYHA. Left ventricular end-diastolic diameter (LVEDd) ,left ventricular ejection fraction(LVEF)and left ventricular fractional shortening (LVFS) are divided separately into three groups randomly as follows: LVEDd ( LVEDd≤60mm,61- 70mm ,LVEDd>70mm ) ,LVFS( LVFS>20,11-20, LVFS≤10 ) and LVEF ( LVEF>30%,21-30%, LVEF≤20% ) .Selected patients are divided into three groups randomly according to the damaged degree of heart function of NYHA(Ⅰ-Ⅱ,Ⅲ,Ⅳ).At the same time all the dates are compared to all kinds of ventricular arrhythmias with SPSS11.5 statistical package,examed byχ2 analysis. The occurance of serious ventricular arrhythmia is related to the LVEF and LVFS,and the difference is conspicuous (P <0.05 ); There is a significant correlation between the monitor according to the damaged degree of heart function of NYHA and serious ventricular arrhythmia, and the difference is conspicuous (P <0.05);however,there is no correlation between LVEDd and ventricular arrhythmia, and the difference isn't conspicuous(P >0.05).At the same time there is no correlation between the LVEF,LVFS,LVEDd and abiogenesis ventricular arrhythmia,the difference isn't significance(P >0.05).The incidence rate of the continual ventricular arrhythm is conspicuous elevated among the groups of LVFS≤10%,LVEF≤30%.At present there are many reports about the correlation factor that the incidence of DCM with ventricular arrhythmia in and outside country,while a few report about that only compared by left ventricular function.We systems analyze all the dates from the values that reflect left heart function by heart color Doppler. There is a sgnificant correlation between the ventricular arrhythmia of DCM and degree of left ventricular function injury. The more severe the cardiovascular hypofunction,the more frequent the incidence of ventricular arrhythm is,and the incidence rate of the severe arrhythm is conspicuous increase initiated by this.It is one of the reason that the patients with DCM suddenly die.We can control the incidence of ventricular arrhythm by improving heart function of DCM, accordingly elevate the patients, quality of life.