“I Dread the Heart Surgery but it Keeps My Child Alive”—Experiences of Parents of Children with Right Ventricular Outflow Tract Anomalies during the Assessment for Cardiac Reoperation

Background:Parents of children with complex right ventricular outflow tract(RVOT)anomalies are confronted with their child’s need for heart surgery early in life and repeated reoperations later on.Preoperative assessment needs to be performed whenever an indication for reoperation is suspected.The aim was to illuminate the experiences of parents of children diagnosed with RVOT anomalies,in particular,how they experience their child’s heart disease and everyday life during the assessment and after the decision on whether to perform a reoperation.Method:Individual interviews(n=27)were conducted with nine parents on three occasions between 2014 and 2016 and analyzed using reflexive thematic analysis.Results:The analysis resulted in the following five main coexisting themes:The heart surgery keeps my child alive illuminates parents’experiences during and after the assessment and emphasizes that heart surgery,although dreaded,is central for their child’s survival;Everyday struggles illuminates the different struggles parents had to face to ensure that their child would be in the best possible condition;the remaining three themes,Unconditional love,Trust in life,and Togetherness,illuminate the ways in which the parents gained inner strength and confidence in their everyday lives.Conclusion:Although the parents were grateful for the assessment and had learned to navigate among the fears it aroused,they experienced several distressing situations during the assessment process that should be addressed.By inviting both the parents and their child to participate in the child’s care,individualized support can take into account the needs of both parents and child.

Right Ventricular Outflow Tract Septal Pacing versus Apical Pacing: A Prospective, Randomized, Single-blind 5-Years Follow-up Study of Ventricular Lead Performance and Safety

Summary： Lead placement for ventricular pacing variably impacts the physiological benefit of the pa- tient. This study evaluated the ventricular lead performance and safety of right ventricular outflow tract septal pacing in patients with bradyarrhythmia in South China over 60-month follow-up. Totally, 192 patients （108 males, and 84 females, 63-4-21 years old） with bradyarrhythmia were randomly divided into two groups. The right ventricular outflow tract septum （RVOTs） group had lead placement near the sep- tum （n=97）, while the right ventricular apex （RVA） group had a traditional apical placement （n=95）. RV septal lead positioning was achieved with a specialized stylet and confirmed using fluoroscopic projec- tion. All patients were followed up for 60 months. Follow-up assessment included stimulation threshold, R-wave sensing, lead impedance and lead complications. The time of electrode implantation in both the ROVTs and RVA groups were significantly different （4.29±0.61 vs. 2.16±0.22 min; P=0.009）. No dif- ferences were identified in threshold, impedance or R-wave sensing between the two groups at 1 st, 12th, 36th and 60th month during the follow-up period. No occurrence of electrode displacement, increased pacing threshold or inadequate sensing was found. The long-term active fixation ventricular electrode performance in RVOTs group was similar to that in RVA group. RVOTs pacing near the septum using active fixation electrodes may provide stability during long-term follow-up period.

Implantation of Lumenless Pacing Leads at the Inter-atrial Septum and Right Ventricular Outflow Tract with Deflectable Catheter-sheath

Current permanent right ventricular and right atrial endocardial pacing leads are implanted utilizing a central lumen stylet. Right ventricular apex pacing initiates an abnormal asynchronous electrical activation pattern, which results in asynchronous ventricular contraction and relaxation. When pacing from right atrial appendage, the conduction time between two atria will be prolonged, which results in heterogeneity for both depolarization and repolarization. Six patients with Class Ⅰ indication for permanent pacing were implanted with either single chamber or dual chamber pacemaker. The SelectSecure 3830 4-French （Fr） lumenless lead and the SelectSite C304 8.5-Fr steerable catheter-sheath （Medtronic Inc., USA） were used. Pre-selected pacing sites included inter-atrial septum and right ventricular outflow tract, which were defined by ECG and fluoroscopic criteria. All the implanting procedures were successful without complication. Testing results （mean atrial pacing threshold： 0.87 V; mean P wave amplitude： 2.28 mV; mean ventricular pacing threshold： 0.53V; mean R wave amplitude： 8.75 mV） were satisfactory. It is concluded that implantation of a 4-Fr lumenless pacing lead by using a streerable catheter-sheath to achieve inter-atrial septum or right ventricular outflow tract pacing is safe and feasible.

Long-term follow-up of right ventricular outflow tract septal pacing

客观恰好室的流出道中隔广泛地变得使用我们一个电极放置地点。然而，有关为与这种技术重新定位的铅的铅表演和复杂并发症的数据是欠缺的。这研究的目的是观察长期的铅表演和恰好室的流出道的复杂并发症氏族的踱步并且为选择一个最佳的电极培植地点提供证据。方法有氏族的活跃电极培植的 36 个病人并且 39 在这研究与顶端的被动电极培植被注册。为在培植和后续的二个组的踱步的阀值，察觉到的 R 波浪，铅阻抗，踱步的 QRS 宽度和步相关的复杂并发症被比较。在那里的结果更高与顶端的组相比在氏族的组在培植正在在阀值和更短的踱步 QRS 宽度上踱步。在之间没有差别氏族并且在在后续期间在阀值， R 波浪敏感，铅阻抗和步相关的复杂并发症上踱步的顶端的组。因为它与传统的顶端的地点相比有长期的稳定的铅表演和没有严肃的复杂并发症，结论恰好室的流出道中隔能为培植地点被用作第一种选择。

Right Ventricular Myxoma Causing Right Ventricular Outflow Tract Obstruction: A Case Report

A 63-year-old patient presented with dyspnea and chest distress. A computerized tomography and echocardiogram showed a cardiac mass in the right ventricle, which caused obstruction of the right ventricular outflow tract. Coronary angiography revealed a dense meshwork of the abnomorly capillary vessels originating from right coronary artery. The mass was completely excised under cardiopulmonary bypass. The mass attached right ventricle lateral wall and posterior triscupid leaflet. Histology was typical myomatous tissue.

Comparison of His-purkinje bundle pacing and right ventricular inflow tract septal pacing in the elderly

Objective To compare the short-term clinical effect and electrical parameters of His-purkinje bundle pacing(HPBP) and right ventricular inflow tract septal pacing(RVIP) in the elderly. Methods Between April 2017 and September 2019, sixty patients with indications for permanent cardiac pacing and resynchronization therapy in Beijing Anzhen Hospital were divided into the HPBP and RVIP groups, and were analyzed. A ventricular pacing lead was implanted in left ventricular septal sites with left bundle potentials or His potentials in the HPBP group. The lead was placed in right ventricular inflow tract septal sites close to distal His-bundle regions without potentials from the His-purkinje conduction system in the RVIP group. Lead impedance, R wave amplitude, pacing thresholds, QRS duration, left ventricular ejection fraction(LVEF), and left ventricular end-diastolic diameter(LVEDD), mitral regurgitation area reflux, QTc, T wave directivity, Tp-e and Tp-e/QT ratio were compared between the HPBP and RVIP groups during the procedure and the short-month follow-up. Results No significant differences were found in lead impedance, R wave amplitude, QRS duration, LVEF, LVEDD, mitral regurgitation area reflux, QTc, T wave directivity, Tp-e and Tp-e/QT ratio between the HPBP and RVIP groups. However, the pacing threshold was significantly lower in the HPBP group than in the RVIP group(0.7 ± 0.2 vs. 0.9 ± 0.3 V, P = 0.02). Conclusions The efficacy and electrical parameters of HPBP is comparable with RVIP during the procedure and the short-term follow-up.

Polytetrafluoroethylene Patch versus Autologous Pericardial Patch for Right Ventricular Outflow Tract Reconstruction in Patients with Tetralogy of Fallot

Objective: For patients of TOF with pulmonary annular hypoplasia, reconstruction of right ventricular outflow tract (RVOT) often requires a trans annular patch (TAP). The present study aims to compare the outcomes of TOF repair using Polytetrafluoroethylene (PTFE) patch versus autologous glutaraldehyde fixed pericardial patch for RVOT reconstruction. Materials and methods: 103 consecutive patients undergoing TOF repair in whom TAP was required were randomized into two groups: Group I (pericardial patch), Group II (PTFE patch). Postoperative outcomes in terms of postoperative heart rhythm, duration of mechanical ventilation, mediastinal and pleural drainage, length of stay in intensive care unit (ICU) and hospital mortality were assessed. A separate team of cardiologists independently evaluated pre- and post-operative gradients across the RVOT, degree of pulmonary insufficiency, right ventricular systolic function. Results: There were no significant differences between the two groups in terms of the incidence of postoperative arrhythmias, duration of mechanical ventilation, length of intensive care unit or hospital stay. The requirement of inotropes was no different in the PTFE patch group as compared with the pericardial patch group (16.84 ± 7.04 vs. 17.90 ± 6.71, median 19 vs. 20, p = 0.825). The re-exploration rate was higher in the PTFE group as compared with the pericardial patch group (6 vs. 1). Postoperative Echocar-diography revealed no differences in the RV systolic function between the two groups before discharge. Conclusion: In patients undergoing TOF repair, using a PTFE patch yields comparable results. However, the efficacy of PTFE will only be established once;mid-term and long-term results are available.

Coronary Artery Complications after Right Ventricular Outflow Tract Reconstruction Surgery

Background:Mechanisms and clinical manifestations of coronary artery complications after right ventricular outflow tract reconstruction surgery are not well known.Methods:Patients who had coronary artery complications after pulmonary valve replacement or the Rastelli procedure at a single tertiary centre were retrospectively analysed.Results:Coronary artery complications were identified in 20 patients who underwent right ventricular outflow tract reconstruction surgery.The median age at diagnosis of coronary artery complication was 21 years(interquartile range:13–25 years).Mechanisms of coronary artery complications were compression by adjacent materials in 12 patients,dynamic compression of intramural course of coronary artery in two patients,and intraoperative injury in six patients.Congenital coronary artery anomalies were identified in 50%(10/20)of patients.Four patients presented with early postoperative haemodynamic instability.Fourteen patients showed late onset symptoms or signs of coronary insufficiency,including chest pain,ventricular dysfunction,or ventricular arrhythmias.Coronary artery stenosis was incidentally found on cardiac computed tomography angiography in two asymptomatic patients.Four patients underwent surgical interventions,and one patient underwent percutaneous coronary intervention for coronary stenosis.One patient with recurrent ventricular tachycardia required an implantable cardioverter-defibrillator.There were two deaths in patients with intraoperative coronary injury.Conclusion:Preoperative coronary evaluation and long-term follow-up for the development of coronary artery complications are required in patients undergoing right ventricular outflow tract reconstruction surgery to prevent ventricular dysfunction,arrhythmias,and death,especially among those with congenital coronary anomalies.

HRV changes before and after radiofrequency ablation in patients with different origin of right ventricular outflow tract ventricular premature contraction

Objective:To observe the HRV changes before and after the radiofrequency current catheter ablationventricular premature beats originated from different site of right ventricular outflow tract.Methods:A total of 102 patients with frequent RVOT-VPC admitted to our hospital were accepted radiofrequency current catheter ablation (RF). According to the origin of RVOT-VPC, it was divided into 2 groups, one is from ventricular septum, and the other one is from free wall, and in each group, male and female are observed separately.Results:(1) HRV before RF ablation: 1) rMSSD in the female patients with RVOT-VPC from free wall was significantly lower than those from septum;2) frequency domain index (W, LF) were higher than normal range, and in male patients, LF/HF<1 were found, but in female patients, LF/HF>1. (2) HRV after RF ablation: 1) Significant changes were found in female patients with RVOT-VPC from septum, rMSSD, PNN50, HF and LF decreased;2) In female patients with RVOT-VPC from free wall, rMSSD decreased;3) In male patients, there were no significant HRV changes found before and after RF ablation. (3) Heart rate changes: 1) In female patients with RVOT-VPC from septum, heart rate decreased significantly ((76.47±9.47) bpm vs (69.29±14.59) bpm)2) No significant changes were found in male patients.Conclusion:In patients with RVOT-PVC sympathetic and vagus excitability increased, and after catheter ablation, in female patients with RVOT-PVC originated from septum, the HRV index relating to sympathetic and vagus excitability significantly decreased.

Right ventricular septal pacing: Safety and efficacy in a long term follow up

AIM: To evaluate the safety and efficacy of the permanent high interventricular septal pacing in a long term follow up, as alternative to right ventricular apical pacing. METHODS: We retrospectively evaluated:(1) 244 patients(74 ± 8 years; 169 men, 75 women) implanted with a single(132 pts) or dual chamber(112 pts) pacemaker(PM) with ventricular screw-in lead placed at the right ventricular high septal parahisian site(SEPTAL pacing);(2) 22 patients with permanent pacemaker and low percentage of pacing(< 20%)(NO pacing);(3) 33 patients with high percentage(> 80%) right ventricular apical pacing(RVA). All patients had a narrow spontaneous QRS(101 ± 14 ms). We evaluated New York Heart Association(NYHA) class, quality of life(Qo L), 6 min walking test(6MWT) and left ventricular function(end-diastolic volume, LV-EDV; end-systolic volume, LVESV; ejection fraction, LV-EF) with 2D-echocardiography. RESULTS: Pacing parameters were stable duringfollow up(21 mo/patient). In SEPTAL pacing group we observed an improvement in NYHA class, Qo L score and 6MWT. While LV-EDV didn't significantly increase(104 ± 40 m L vs 100 ± 37 m L; P = 0.35), LV-ESV slightly increased(55 ± 31 m L vs 49 ± 27 m L; P = 0.05) and LV-EF slightly decreased(49% ± 11% vs 53% ± 11%; P = 0.001) but never falling < 45%. In the RVA pacing control group we observed a worsening of NYHA class and an important reduction of LV-EF(from 56% ± 6% to 43% ± 9%, P < 0.0001).CONCLUSION: Right ventricular permanent high septal pacing is safe and effective in a long term follow up evaluation; it could be a good alternative to the conventional RVA pacing in order to avoid its deleterious effects.

The importance of avoiding unnecessary right ventricular pacing in clinical practice

Symptomatic bradycardia is effectively treated with the implantation of a cardiac pacemaker. Although a highly successful therapy, during recent years there has been a focus on the negative effects associated with longterm pacing of the apex of the right ventricle(RV). It has been shown in both experimental and clinical studies that RV pacing leads to ventricular dyssynchrony, similar to that of left bundle branch block, with subsequent detrimental effects on cardiac structure and function, and in some cases adverse clinical outcomes such as atrial fibrillation, heart failure and death. There is substantial evidence that patients with reduced left ventricular function(LVEF) are at particular high risk of suffering the detrimental clinical effects of long-term RV pacing. The evidence is, however, incomplete, coming largely from subanalyses of pacemaker and implantable cardiac defibrillator studies. In this group of patients with reduced LVEF and an expected high amount of RV pacing, biventricular pacing(cardiac resynchronization therapy) devices can prevent the negative effects of RV pacing and reduce ventricular dyssynchrony. Therefore, cardiac resynchronization therapy has emerged as an attractive option with promising results and more clinical studies are underway. Furthermore, specific pacemaker algorithms, which minimize RV pacing, can also reduce the negative effects of RV stimulation on cardiac function and may prevent clinical deterioration.

Hemodynamic improvement by right ventricular septal pacing in elderly patients with chronic atrial fibrillation and slow ventricular response

Background and objectives Right ventricular apical (RVA) pacing has been reported impairing left ventricular (LV)performance. Alternative pacing sites in right ventricle (RV) has been explored to obtain better cardiac function. Our study was designed to compare the hemodynamic effects of right ventricular septal (RVS) pacing with RVA pacing. Methods Ten elderly patients with chronic atrial fibrillation (AF) and long RR interval or slow ventricular response (VR) received VVI pacing. The hemodynamic difference between RVS and RVA pacing were examined by transthoracic echocardiography (TTE). Results Pacing leads were implanted successfully at the RVA and then RVS in all patients without complication. The left ventricular (LV) parameters,measured during RVA pacing including left ventricular ejection fraction (LVEF), FS, stroke volume (SV) and peak E wave velocity (EV) were decreased significantly compared to baseline data, while during RVS pacing, they were significantly better than those during RVA pacing. However, after 3-6 weeks there was no statistical significant difference between pre- and post- RVS pacing.Conclusions The LV hemodynamic parameters during RVA pacing were significantly worse than baseline data. The short term LV hemodynamic parameters of RVS pacing were significantly better than those of RVA pacing; RVS pacing could improve the hemodynamic effect through maintaining normal ventricular activation sequence and biventricular contraction synchrony in patients with chronic AF and slow ventricular response.

希氏束起搏与右心室心尖部起搏对房室传导阻滞患者心脏结构学参数与功能学参数影响的临床研究

目的:探究希氏束起搏(HBP)与右心室心尖部起搏(RVAP)对房室传导阻滞(AVB)患者心脏结构学参数与功能学参数的影响。方法:选取收治的104例AVB患者为研究对象,随机分为HBP组和RVAP组各52例,HBP组行HBP治疗,RVAP组行RVAP治疗,比较两组术前、术后心脏结构学参数、心脏起搏参数、心率和血流动力学参数[心率(HR)、每搏输出量(SV)、心脏指数(CI)和左室射血分数(LVEF)]及QRS时限变化情况。结果:两组手术前后心脏结构学参数左心室收缩末期内径(LVESD)、左心室舒张末期内径(LVEDD)、室间隔厚度(IVS)、左室后壁厚度(LVPW)比较,差异均无统计学意义(均P>0.05);术中、术后1个月、术后6个月心脏起搏阈值、R波幅度、电极阻抗比较无统计学差异(均P>0.05);术前、术后1个月,两组HR、SV、CI、LVEF、QRS时限比较无统计学差异(均P>0.05);术后6个月,HBP组HR、SV、CI、LVEF显著高于RVAP组(均P<0.05),RVAP组QRS波时限显著低于HBP组(P<0.05);结论:HBP对AVB患者的电-机械同步性优于RVAP,近期心脏血流动力学及心功能稳定性良好。

磁导航在右心室流出道起源室性早搏导管消融中的应用

目的探讨磁导航指导下右心室流出道(right ventricular outflow tract,RVOT)起源室性早搏(简称室早)导管消融的有效性、安全性。方法选取92例接受磁导航指导下导管消融的RVOT起源室早患者,按室早起源部位将其分为前间隔组(35例)、中间隔组(26例)、后间隔组(11例)、前游离壁组(4例)、中游离壁组(10例)和后游离壁组(6例)6组。分析6组RVOT起源室早不同起源部位的发病率,并比较6组的消融急性成功率、复发率及安全性。结果RVOT前间隔起源的室早发病率最高,消融急性成功率100%。术后一年,仅RVOT中间隔起源的室早复发,复发率为7.69%。所有患者术中及术后均无手术相关并发症发生。结论RVOT室早多起源于前间隔和中间隔,磁导航指导下的导管消融对此具有较高的有效性和安全性。

Evaluation of global and regional left ventricular systolic function in patients with frequent isolated premature ventricular complexes from the right ventricular outflow tract

Background Frequent premature ventricular complexes from the right ventricular outflow tract （RVOT-PVCs） are associated with left ventricular dysfunction.This study adopted two-dimensional speckle tracking imaging to evaluate global and regional left ventricular myocardial function in patients with frequent RVOT-PVCs.Methods This study included 30 patients with frequent RVOT-PVCs and 30 healthy subjects.Aortic systolic velocity-time integral （AoVTI） and myocardium strain in circumferential （CS）,radial （RS） and longitudinal （LS） directions were evaluated by conventional echocardiography and speckle tracking imaging.All values of patients with RVOT-PVCs were recorded during sinus （PVC-S） and PVC beats （PVC-V）.Results Significant differences were demonstrated in global CS,RS and LS between the control subjects and the PVC-V （CS：（17.46±2.48）% vs.（11.52±3.28）%,RS：（48.26±10.20）% vs.（20.92±9.78）%,LS：（19.89±2.62）% vs.（11.79±3.66）%,P 〈0.01）,and in segmental RS and LS of nearly all the left ventricular segments.Statistical differences in segmental CS between the PVC-V and the control subjects were only observed in anterior,anteroseptal and septal segments （only seen in anteroseptal and septal segments at apex）.Furthermore,V/S AoVTI （AoVTI during the PVC beat divided by AoVTI during the sinus beat,then multiplied by 100%） correlated with coupling interval （r=0.67,P 〈0.001） and global strain （CS：r=0.48,P=0.007; RS：r=0.65,P 〈0.001; LS：r=0.65,P 〈0.001）.Conclusions Frequent RVOT-PVCs can induce global and regional left ventricular systolic dysfunction.The reduction of hemodynamic parameters relates to the coupling interval and the global systolic function.

Trigger elimination of polymorphic ventricular tachycardia and ventricular fibrillation by catheter ablation:trigger and substrate modification

Ventricular fibrillation （VF） is a malignant arrhythmia, usually initiated by a ventricular premature contraction （VPC） during the vulnerable period of cardiac repolarization. Ablation therapy for VF has been described and increasingly reported. Targets for VF triggers are VPCs preceded by Purkinje potentials or from the right ventricular outflow tract （RVOT） in structurally normal hearts, and VPC triggers preceded by Purkinje potentials in ischemic cardiomyopathy. During the session, mapping should be focused on the earliest activation and determining the earliest potential is the key to a successful ablation. However, suppression of VF can be achieved by not only the elimination of triggering VPCs, but also by substrate modification of possible reentry circuits in the Purkinje network, or between the PA and RVOT. The most important issue before the ablation session is the recording of the 12-lead ECG of the triggering event, which can prove invaluable in regionalizing the origin of the triggering VPC for more detailed mapping. In cases where the VPC is not spontaneous or inducible, ablation may be performed by pace mapping. Further studies are needed to evaluate the precise mechanisms of this arrhythmia.

L-type calcium current in right ventricular outflow tract myocytes of rabbit heart

The mechanism of idiopathic ventricular tachycardia originating from the right ventricular outflow tract (RVOT) is not clear. Many clinical reports have suggested a mechanism of triggered activity. However, there are few studies investigating this because of the technical difficulties associated with examining this theory. The L-type calcium current (ICa-L), an important inward current of the action potential (AP), plays an important role in arrhythmogenesis. The aim of this study was to explore differences in the APs of right ventricular (RV) and RVOT cardiomyocytes, and differences in electrophysiological characteristics of the ICa-L in these myocytes. Rabbit RVOT and RV myocytes were isolated and their AP and ICa-L were investigated using the patch-clamp technique. RVOT cardiomyocytes had a wider range of AP duration (APD) than RV cardiomyocytes, with some markedly prolonged APDs and markedly shortened APDs. The markedly shortened APDs in RVOT myocytes were abolished by treatment with 4-AP, an inhibitor of the transient outward potassium current, but the markedly prolonged APDs remained, with some myocytes with a long AP plateau not repolarizing to resting potential. In addition, early afterdepolarization (EAD) and second plateau responses were seen in RVOT myocytes but not in RV myocytes. RVOT myocytes had a higher current density for ICa-L than RV myocytes (RVOT (13.16±0.87) pA pF-1, RV (8.59±1.97) pA pF-1; P<0.05). The ICa-L and the prolonged APD were reduced, and the EAD and second plateau response disappeared, after treatment with nifedipine (10 μmol L-1), which blocks the ICa-L. In conclusion, there was a wider range of APDs in RVOT myocytes than in RV myocytes, which is one of the basic factors involved in arrhythmogenesis. The higher current density for ICa-L is one of the factors causing prolongation of the APD in RVOT myocytes. The combination of EAD with prolonged APD may be one of the mechanisms of RVOT-VT generation.

Left ventricular endocardial pacing predicts the reduction of left ventricular outflow tract pressure gradient immediately after percutaneous transseptal myocardial ablation in patients with hypertrophic obstructive cardiomyopathy refractory to medicatio

Background Hypertrophic obstructive cardiomyopathy （HOCM） carries an increased risk for sudden cardiac death. No data regarding the percutaneous transseptal myocardial ablation （PTSMA） and epicardial left ventricular pacing （LVP） were reported. Methods Seven patients with recurrent symptoms and increased resting left ventricular outflow tract pressure gradient （LVOTG） after PTSMA and another 14 patients with HOCM without history of PTSMA were studied. Both resting and dobutamine stress echocardiography, PTSMA and LVP were routinely performed. Results In patients without previous PTSMA procedure, mild reduction of resting LVOTG was detected at 5 minutes after left ventricular pacing, and this reduction became significant at 10 minutes. All patients were divided into successful and unsuccessful groups according to their response to LVP. In contrary to patients in unsuccessful group, resting and R-S2 stimuli-induced LVOTG during PTSMA procedure were decreased dramatically （（9±5） mmHg vs （58±12） mmHg, （12±2） mmHg vs （113±27） mmHg, P〈0.001）. Analysis of Logistic regression demonstrated that only LVOTG level dudng left ventdcular pacing was an independent factor predicting the reduction of LVOTG immediately after PTSMA （odds ratio （OR）, 0.59; 95% CI 2.67 to 5.82; P=0.0002）. Conclusion Left ventricular endocardial temporary pacing plays a critical role in predicting acute effect on the reduction of LVOTG immediately after PTSMA procedure.

Handmade tri-leaflet ePTFE conduits versus homografts for right ventricular outflow tract reconstruction

Background This study aimed to investigate the performance of handmade tri-leaflet expanded polytetrafluoroethylene(ePTFE)conduits in the absence of a suitable homograft.Methods Patients who underwent right ventricular outflow tract reconstruction with tri-leaflet ePTFE conduits or homografts between December 2016 and August 2020 were included.The primary endpoint was the incidence of moderate or severe conduit stenosis(>36 mmHg)and/or moderate or severe insufficiency.The secondary endpoint was the incidence of severe conduit stenosis(>64 mmHg)and/or severe insufficiency.Results There were 102 patients in the ePTFE group and 52 patients in the homograft group.The median age was younger[34.5(interquartile range:20.8-62.8)vs.60.0(interquartile range:39.3-81.0)months,P=0.001]and the median weight was lower[13.5(10.0-19.0)vs.17.8(13.6-25.8)kg,P=0.003]in the ePTFE group.The conduit size was smaller(17.9±2.2 vs.20.5±3.0 mm,P<0.001)and the conduit Z score was lower(1.48±1.04 vs.1.83±1.05,P—0.048)in the ePTFE group.There was no significant difference in the primary endpoints(log rank,T3=0.33)and secondary endpoints(log rank,P=0.35).Multivariate analysis identified lower weight at surgery[P=0.01;hazard ratio:0.75;95%confidence interval(CI)0.59-0.94]and homograft conduit use(P=0.04;hazard ratio:8.43;95%CI 1.14—62.29)to be risk factors for moderate or severe conduit insufficiency.No risk factors were found for moderate or severe conduit stenosis or conduit dysfunction on multivariate analysis.Conclusion Handmade tri-leaflet ePTFE conduits showed acceptable early and midterm outcomes in the absence of a suitable homograft,but a longer follow-up is needed.