| Background: tachycardia-bradycardia syndrome is a long pause after rapid atrial cardiac arrhythmia(mainly refers to paroxysmal atrial fibrillation)and before the restoration of sinus rhythm.The patient will have chest tightness,shortness of breath,amaurosis,even syncope and other symptoms.The mechanism of its occurrence is not very clear.The explanation,such as overdrive suppression,ischemia,electrical remodeling are not fully explain the long intermission after paroxysmal atrial fibrillation.Part of sinus node recovery time of patients with tachycardia-bradycardia syndrome is normal.The duration of atrial fibrillation(AF)and the severity of long interval are not always relevant.According to the molecular biology research on arrhythmia in recent years,it has been found that there is a close relationship between many arrhythmia and genetic regulation anomaly.In recent years,more than 30 atrial fibrillation pathogenic and susceptible genes are found;in addition,genome-wide association studies also found more than 10 single nucleotide polymorphism sites associated with atrial fibrillation.A gene mutation can cause different arrhythmias,or a combination.The same phenotype may be associated with a variety of gene mutations because of the presence of genetic heterogeneity.The close relationship of gene and arrhythmia provides a new way of thinking for studies of long intermittent mechanism after paroxysmal atrial fibrillation.However,gene testing is only carried out in a few centers now,which is expensive and has a long cycle,so it is not widely carried out.However,conventional 12 lead ECG can reflect the changes of whole heart,local electrical activity,and ion flow constituting the basis of ECG activity and its related genes.Recently,some studies also found some electrocardiogram indexes related genes and SNPs,which confirms various ECG performances have their molecular biology foundation.And finding out the relationship between ECG changes and specific gene site corresponding to these electrical disturbances is especially suitable for clinical.In addition,abnormal cardiac autonomic nervous system is closely related to the occurrence and maintenance of atrial fibrillation,and the changes of autonomic nervous tension will change each band of ECG.Objective: the aim of this study is to analyze the characteristics of sinus rhythm electrocardiogram indexes in patients with long pause after termination of paroxysmal atrial fibrillation,and to explore the possible mechanism of long interval after termination of paroxysmal atrial fibrillation.Methods: We selected 170 patients who had dynamic ECG monitoring and were diagnosed as patients with paroxysmal atrial fibrillation in our hospital from January 2014 to October 2015 and collected the history of atrial fibrillation,age,gender,underlying diseases,the history of amaurosis or syncope,echocardiographic indexes,use of antiarrhythmic drug and other indexes of them.According to that whether they have a more than or equal to 2S long RR interval after atrial fibrillation termination,we divided them into long RR interval group(long pause group)of 70 cases and no long RR interval group(control group,n)of 100 cases.ECG indicators of two groups of patients with sinus rhythm were measured separately,including sinus average heart rate within 24 hours,resting heart rate,II lead P wave duration and amplitude,PR interval,QRS duration,QT and QTc interval,the shape of the ST segment,T wave morphology,conduction abnormalities,right bundle branch and left bundle branch block,J wave and Brugada wave.Compare the ECG indexes differences between long interval group and the control group.Results: 1.Age,gender,history of atrial fibrillation,underlying diseases,cardiac indexes,the use of antiarrhythmic drugs of two groups of patients were not significantly different.The incidence of amaurosis or syncope of long intermittent is higher than that of the control group and has a significant difference.2.The average heart rate of sinus of patients with long pause group was lower than that of control group,and there was significant difference(P<0.001)between 24 hours;long interval group sinus resting heart rate was lower than control group(P < 0.05);PR interval was greater than the control group(P < 0.01);QT interval and QTc interval were greater than the control group(P < 0.05);II lead P wave duration between the two groups had no significant difference(P > 0.05);II lead P wave amplitude of intermittent group was lower than that of the control group,but there was no statistical difference(P > 0.05).T wave and ST segment shape and right bundle branch block,second degree sinoatrial block occurrence rate between the two groups had no significant difference(P>0.05);the left bundle branch block,two degree and three degree atrioventricular block,Brugada wave,J wave of two groups of patients were not recorded.Conclusion: sinus rhythm ECG indicators of patients with paroxysmal atrial fibrillation appear changes of heart rate slowed down,PR interval prolongation,QT interval and QTc interval prolongation,which suggests that the patients may have a long interval after the termination of paroxysmal atrial fibrillation. |
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