| Part Ⅰ The effect of Liwen procedure for hypertrophic obstructive cardiomyopathy on arrhythmiasObjective Using 24-hour dynamic electrocardiogram and 12-lead resting electrocardiogram to evaluate the occurrence and outcomes of arrhythmias in patients of hypertrophic obstructive cardiomyopathy(HOCM)treated by echocardiography-guided percutaneous intramyocardial septal radiofrequency ablation(Liwen procedure),to provide dimension of electrocardiogram for the prognosis evaluation of HOCM patients treated by Liwen procedure.Methods Eighty-five patients with HOCM who underwent Liwen procedure in the Hypertrophic Cardiomyopathy Center of Xijing Hospital,Air Force Military Medical University from May 2017 to October 2019 were retrospectively analyzed.The maximum end-diastolic interventricular septal thickness(MIVSTd),resting and provocative left ventricular outflow tract pressure gradient(LVOTG),left ventricular outflow tract diameter(LVOTd),left ventricular end-diastolic volume(LVEDV),left ventricular endsystolic volume(LVESV),left ventricular ejection fraction(LVEF),E/e’ ratio,left atrial end-systolic anteroposterior diameter(LAESD-ap)were measured before,1 month,6 months and the last follow up,the changes in the above parameters before and after the Liwen procedure were compared.Resting ECG parameters such as PR interval,QRS interval,QTc interval,Rv5+Sv1,pathological Q wave,fragmented QRS wave,and the occurance of atrial tachyarrhythmias such as premature atrial contractions(PACs),atrial tachycardia(AT),atrial fibrillation(AF),atrial flutter,ventricular tachyarrhythmias such as premature ventricular contractions(PVCs),sustained/non-sustained ventricular tachycardia(SVT/NSVT),ventricular fibrillation(VF),Lown classification,and bradyarrhythmias such as complete left bundle branch block(CLBBB),complete right bundle branch block(CRBBB),complete heart block(CHB)were comprehensive analyzed.Results(1)Compared with pre-operation,MIVSTd,LVOTd,and resting LVOTG decreased significantly from 1 month after operation(all P<0.05);Provocative LVOTG,E/e’ ratio,and LAESD-ap decreased significantly from 6 months after operation(all P<0.05).Compared with before operation,LVEDV,LVESV and LVEF had no significant changes(all P>0.05).(2)Compared with pre-operation,the QRS interval increased and Rv5+Sv1 decreased at the last follow-up(both P<0.05);The PR interval,QTc interval,and the incidences of pathological Q wave,fragmented QRS wave did not change significantly at follow-up compared with before(all P>0.05).(3)No patient suffered from malignant arrhythmias such as SVT,VF,CHB after Liwen procedure,and no patient needed to be implanted permanent pacemaker;From 1 month after operation,the incidence of multifocal PVCs and the proportion of patients with Lown≥Ⅲ grade decreased significantly(both P<0.05);Compared with pre-operation,the total number of PACs,coupled PACs,AT,AF,atrial flutter and other atrial tachyarrhythmias,the total number of PVCs,PVCs burden,frequent PVCs,coupled PVCs,NSVT,R on T and other ventricular tachyarrhythmias,CLBBB,CRBBB and other bradyarrhythmias did not change significantly after operation(all P>0.05).Conclusions Liwen procedure could significantly improve the hemodynamics of HOCM patients,and no increase in the risk of arrhythmias was observed in the short and mid-term follow-up.Based on the original ventricular arrhythmias,Liwen procedure could reduce the severity of ventricular arrhythmias in HOCM patients to varying degrees.This study can provide electrocardiogram dimension for the evaluation of Liwen procedure.Part Ⅱ Study on related factors for ventricular arrhythmias of Liwen procedure on hypertrophic obstructive cardiomyopathyObjective To investigate the effect and influencing factors of Liwen procedure on ventricular arrhythmias in HOCM patients,so as to provide reference for personalized operation strategy and prognosis evaluation.Methods A total of 85 patients with HOCM who underwent Liwen procedure in the Hypertrophic Cardiomyopathy Center of Xijing Hospital,Air Force Military Medical University from May 2017 to October 2019 were retrospectively analyzed.All patients underwent 24-hour dynamic electrocardiogram examinations before and after Liwen procedure to obtain parameters related to Lown classification.Routine echocardiographic parameters such as maximum end-diastolic interventricular septal thickness(MIVSTd),left ventricular outflow tract diameter(LVOTd),resting and provocative left ventricular outflow tract pressure gradient(LVOTG)were measured before and at the last follow-up.Analyzed the correlation between the change degree of Lown grades and volume reduction effect parameters,and combined with the baseline clinical parameters,ablation parameters and volume reduction effect parameters,the factors influencing the improvement of Lown grades were analyzed.Results Compared with before Liwen procedure,the Lown grades was significantly improved(P<0.05).The patients of Lown grade I increased significantly(P<0.001),the patients of grade III decreased significantly(P<0.001).There were no significant changes in Lown grades 0,II,Ⅳa and Ⅳb(all P>0.05).The Lown grades improved in 42 patients,and unimproved in 43 patients.The degree of Lown grades change was linearly positively correlated with the reduction rate of MIVSTd and provocative LVOTG(rs=0.231,P=0.034 and rs=0.267,P=0.015).The baseline Lown grades,the reduction rate of MIVSTd and the reduction rate of the provocative LVOTG were higher in the improved group than the unimproved group(all P<0.05).Multivariate Logistic regression results showed that baseline Lown grades(OR=2.023,95%CI=1.311~3.121,P=0.001)and the reduction rate of the provocative LVOTG(OR=1.021,95%CI=1.004~1.039,P=0.017)were independent factors of Lown grades improvement.Conclusions The Lown grades of HOCM patients after Liwen procedure is significantly improved.After adjusting baseline Lown grades,the reduction rate of provocative LVOTG was an independent influencing factor for the improvement of Lown grades.This study can provide a reference for personalized operation strategy and prognosis evaluation. |
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