Ventricular Arrhythmia Catheter Ablation Of Left Ventricular Papillary Muscle In The Left Ventricle

Background:Ablation of arrhythmias arising from the papillary muscle is challenging and difficult.Objective:Elucidate the characteristics of electrocardiographic(ECG)and electrophysiological characteristics,and results of radiofrequency catheter ablation in patients with idiopathic ventricular arrhythmia(VA)originating from the papillary muscle(PM)in the left ventricle(LV),and compared them with fascicular VA.Methods:We studied fifty-one patients with VA originating from the LV undergoing catheter ablation of idiopathic LV VA between August 2005 to October 2017.Those patients had no evidence of structural heart disease and no evidence of prior infarction.Fifty-one consecutive patients presenting with symptomatic premature ventricular contraction(PVC)or nonsustained ventricular tachycardia(VT)were found to have a site of origin in the posterior papillary muscle of the left ventricle(n=17),or in the anterior papillary muscle of the left ventricle(n=9),and others originating from the left posterior fascicle(n=22)or the left anterior fascicle(n=3).The 51 patients who were selected were classified into two groups according to the site of origin.One group was LPPM compared with LPF,another group was LAPM compared with LAF.These patients were collected at the sinus rhythm(SR)and VA with ECG,respectively recording the duration of the QRS complex with sinus rhythm and the VA VA/SN ratio of duration of the QRS complex,axis of the QRS complex,narrow Q waves and main wave direction in leads V1,I and av L or II,III,and av F,respectively.All patients underwent mapping and ablation.Results:The subjects of this study were 51 patients,seventeen of 51 patients(33%)had VA originating from the LPPM,twenty-two of 51 patients(43%)originating from the LPF,nine of 51 patients(18%)originating from the LAPM,three of 51 patients(6%)originating from LAF.Twelve of 17 Patients with LPPM VA just presented PVC,five patients presented nonsustained VT at the same time,the type of clinical arrhythmia often presented PVC.Patients with LPPM or LAPM VA presented more frequently with PVC rather than sustained or nonsustained VT compared to those with LPF or LAF VA.In the LPPM-LPF group,LPPM often present as PVC compared to LPF(71% vs 10%,P=0.001),In the LAPM-LAF group had similar results(89% vs 33%,P=0.127).The two group were different in the mean QRS duration,the mean QRS duration with LPPM VA(133.6±19.7ms)was significantly broader compared with LPF VA(117.2±15.1ms,P=0.0001).In the group of LAPM-LAF,QRS duration was159.1±21.8ms vs 125.7±6.5ms P=0.0001.The ratio of the VA and SR QRS duration(VA/SR ratio)was the smaller in the LPF VA(1.42±0.21),the VA/SR ratio was1.70±0.32 ms in the LPPM VA with a significant difference(P=0.008),in the group of LAPM-LAF,the VA/SR ratio was 2.0±0.35 vs 1.9±0.38,P=0.796.The main wave direction in leads II III and av F was up in the LPPM group and in the LAPM Group was down.In lead V1,patients with LPPM VA presented with q R had no difference compared to LPF(76% vs 55%,P=0.157),in the group of LAPM-LAF was 89% vs33%,P=0.054.All patients undetwent electroanatomic mapping using the CARTO system.In the LPPM group,thirteen patients can record high frequency potentials in the site of the catheter ablation,at the same time,two of them had recorded the local ventricular muscle potential.Three patients only record the local ventricular muscle potential in the site of the catheter ablation.In the LAPM group,five patients can record high frequency potentials,one of them can also record the local ventricular muscle potential,four patients only record the local ventricular muscle potential.Patients in the LPPM group were all retrograde aortic pathways,all of the 9 patients with LAPM group were ablated by using atrial septal pathway and retrograde aortic pathway.In the LPPM group,the success rate of immediate ablation was 76%.In the LAPM group,the success rate of immediate ablation is 67%.Thirteen patients of the LPPM group used an irrigated tip ablation,two cases had recurrent PVC after ablation,the success rate of immediate ablation is 85%.Four patients used a conventional 4-mm-tip catheter,one case was failed,one case had recurrent,the success rate of immediate ablation is 75%,In the one case,CARTOSOUND was applied to guide ablation.In the LAPM group,all of patients used an irrigated tip ablation,the pericatdial tamponade was only found in 1case from the LAPM group,and the vital signs were stable after pericardial drainage,two patients was failed,six patients was successed.Conclusion We describe the clinical and ECG characteristics that differentiate PM VA in the LV from fascicular VA in the LV.The mean QRS duration with LPPM or LAPM VA was greater than 130 ms.The ratio of the VA and SR QRS duration(VA/SR ratio)was greater than 1.65,in addition to the presence of V1 lead q wave aslo has a diagnostic significance.These differentiating ECG features might be useful for planning an epicardial ablation strategy.Choose the appropriate surgical approach,in the same time,catheter ablation was guided by 3-dimensional voltage map,intracardiac echocardiography may be useful to accurate diagnosis of the VA,and was essential in documenting adequate catheter contact,and greatly improve the ablation success rate and reduce the recurrence rate.Successful catheter ablation at the site usually found Pukinje potentials,it is likely that the Pukinje fibers may be involved in the occurrence of idiopathic VA.