Clinical Characteristics Of Tachycardia-induced Cardiomyopathy In Children And The Comparitive Analysis With Dilated Cardiomyopathy

ObjectiveThis study aimed to investigate the clinical characteristics of tachycardia-induced cardiomyopathy(TIC)and provide the basis for the diagnosis and differential diagnosis.Methods18 patients with TIC in Children’s hospital of Chongqing Medical University from January 2013 to September 2020 were recruited.Their clinical data were retrospectively analyzed and followed up.40 patients with dilated cardiomyopathy(DCM)who were hospitalized with these 18 patients at the same time were selected as DCM group.The clinical features,treatment and prognosis of TIC group and DCM group were analyzed.ResultsThe percentage of atrial tachycardia in patients with TIC was88.9%(16/18).The degree of tachycardia load in children with moderate to severe impairment of left ventricular systolic function was more severe than that in children with mild impairment of left ventricular systolic function(P < 0.05).Seven cases underwent catheterization for radiofrequency ablation and all succeeded.The cardiac rhythm of 6 out of11 treated with drugs became sinus rhythm.Though the remaining 5 cases still retained ectopic rhythm,the ventricular heart rates,the frequency of arrhythmia attack and the tachycardia load decreased significantly.Compared with DCM group,TIC group had younger diagnosed age,faster heart rate in acute phase,larger heart rate index in acute phase,less moderate to severe heart failure cases,smaller left ventricular end-diastolic dimension z score(LVEDD-Z),larger left ventricular ejection fraction(LVEF)and left ventricular fractional shortening(LVFS)at first visit(P < 0.05).In TIC group,the percentage of ectopic rhythm tachycardia in total heart rate was higher,and B-type natriuretic peptide(BNP)before treatment divided by BNP after treatment within two weeks(BNP-R)was higher.(P < 0.05).After treatment,the cardiac function of TIC group recovered completely and faster,and the reduction of LVEDD-Z was more obvious than that of DCM(P < 0.05).If we use LVEDD-Z(after treatment)> 4.9 as the index to differentiate TIC and DCM,the sensitivity and specificity of diagnosis were 76.3% and100%,respectively.ConclusionAtrial tachycardia is the main type of arrhythmia in children with TIC.The higher the load of ectopic rhythm tachycardia,the more severe the damage of left ventricular systolic function.The basic goal of TIC treatment is to control the ventricular rate at an appropriate level.On this basis,we should strive to convert ectopic rhythm to sinus rhythm.LVEDD-Z >4.9 after treatment can be used as a sensitive and specific index to differentiate TIC from DCM.