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 assess...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.展开更多
Objective: To investigate the electrophysiological changes of autonomic cells in left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with chronic heart failure.Methods: Guinea pigs mo...Objective: To investigate the electrophysiological changes of autonomic cells in left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with chronic heart failure.Methods: Guinea pigs model of iron deficiency anemia complicated with chronic heart failure in 10 guinea pigs of the experimental group was made by feeding a low iron diet,pure water and subcutaneous injection of isoproterenol. The control group consisting of 11 guinea pigs was given normal food, normal water and injected with normal saline. The left ventricular outflow tract model specimen was also prepared. The standard microelectrode technique was used to observe electrophysiological changes of autonomic cells in the outflow tract of left ventricular heart failure complicated with iron deficiency anemia in guinea pig model. The indicators of observation were maximal diastolic potential, action potential amplitude, 0 phase maximal depolarization velocity, 4 phase automatic depolarization velocity, repolarization 50% and 90%, and spontaneous discharge frequency.Results: Compared with the control group, 4 phase automatic depolarization velocity,spontaneous discharge frequency and 0 phase maximal depolarization velocity decreased significantly(P < 0.01) and action potential amplitude reduced(P < 0.01) in model group. Moreover, repolarization 50% and 90% increased(P < 0.01).Conclusions: There are electrophysiological abnormalities of the left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with heart failure.展开更多
Objective: To investigate the electrophysiology effects and mechanism of iron overload on the slow response autorhythmic cells in the left ventricular outflow tract of guinea pigs.Methods: Standard microelectrode cell...Objective: To investigate the electrophysiology effects and mechanism of iron overload on the slow response autorhythmic cells in the left ventricular outflow tract of guinea pigs.Methods: Standard microelectrode cell recording techniques were adopted to observe the electrophysiological effects of different concentrations of Fe^(2+)(100 μmol/L, 200 μmol/L) on the left ventricular outflow tract autorhythmic cells.Heart tissues were perfused with FeSO_4(200 μmol/L) combing with CaCl_2(4.2 mmol/L), Verapamil,(1 μmol/L), and nickel chloride(200μmol/L) respectively to observe the influences of these contents on electrophysiology of FeSO_4(200μmol/L) on the left ventricular outflow tract autorhythmic cells.Results: Fe^(2+)at both 100 μmol/L and 200 μmol/L could change the electrophysiological parameters of the slow response autorhythmic cells of the left ventricular outflow tract in a concentrationdependent manner resulting into decrease in Vmax, APA and MDP, slower RPF and VDD, and prolonged APD_(50) and APD_(90)(P all <0.05).Besides, perfusion of increased Ca^(2+) concentration could partially offset the electrophysiological effects of Fe^(2+)(200 μmol/L).The L-type calcium channel(LTCC) blocker Verapamil(1 μmol/L) could block the electrophysiological effects of Fe^(2+)(200 μmol/L).But the T-type calcium channel(TTCC) blocker nickel chloride(NiCl_2, 200 μmol/L) could not block the electrophysiological effects of Fe^(2+)(200 μmol/L).Conclusions: Fe^(2+) can directly change the electrophysiological characteristics of the slow response autorhythmic cells of the left ventricular outflow tract probably through the L-type calcium channel.展开更多
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 p...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.展开更多
OBJECTIVE: To summarize the experience in modified reconstruction of the hepatic outflow tract during piggyback liver transplantation at our hospital. METHODS: The clinical data on 67 patients undergoing piggyback liv...OBJECTIVE: To summarize the experience in modified reconstruction of the hepatic outflow tract during piggyback liver transplantation at our hospital. METHODS: The clinical data on 67 patients undergoing piggyback liver transplantation with modified hepatic outflow tract reconstruction from January 1999 to October 2002 were analyzed retrospectively. RESULTS: In this group, 7 patients (10. 45%) died perioperatively. Complications included: pulmonary infection (38 patients); multiple organ system failure (10), intraperitoneal bleeding (6), acute respiratory distress syndrome (14), thrombosis of the hepatie artery (1), and bile leakage (1). No hepatic outflow occluded. Two recipients survived for over 3 years, 8 over 2 years, and 19 over a year. CONCLUSION: Modified hepatic outflow reconstruction in piggyback live transplantation may increase the success rate of liver transplantation and decrease technical complications.展开更多
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 patt...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.展开更多
Objective Right ventricular outflow tract septum has become widely used us an electrode placement site. However, data concerning lead performances and complications for lead repositioning with this technique were scan...Objective Right ventricular outflow tract septum has become widely used us an electrode placement site. However, data concerning lead performances and complications for lead repositioning with this technique were scant. The purpose of this study was to observe long- term lead performances and complications of right ventricular outflow tract septal pacing and provide evidences for choosing an optimal electrode implantation site. Methods Thirty-six patients with septal active electrode implantation and 39 with apical passive electrode implantation were enrolled in this study. Pacing threshold, R-wave sensing, lead impedance, pacing QRS width and pacing-related compli- cations for two groups at implantation and follow-up were compared. Results There were higher pacing threshold and shorter pacing QRS width at implantation in the septal group compared with the apical group. There were no differences between the septal and the apical groups in pacing threshold, R-wave sensitivity, lead impedance and pace-related complication during a follow-up. Conclusions Right ventricular outflow tract septum could be used as a first choice for implantation site because it had long-term stable lead performances and no serious complications compared with the traditional apical site.展开更多
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...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.展开更多
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 tra...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.展开更多
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 ...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.展开更多
Idiopathic monomorphic ventricular tachycardia and premature ventricular complexes (PVCs) commonly arise from the right and left ventricular outflow tracts (VOT). Their mechanism is most commonly triggered activity fr...Idiopathic monomorphic ventricular tachycardia and premature ventricular complexes (PVCs) commonly arise from the right and left ventricular outflow tracts (VOT). Their mechanism is most commonly triggered activity from delayed after-depolarizations and successful ablation is performed at the site of earliest endocardial activation. Re-entrant mechanisms have been rarely described. We report a case of an otherwise healthy patient who ultimately underwent six electro-physiology studies (EPS) and suffered numerous implantable cardiac defibrillator (ICD) discharges prior to the successful radiofrequency ablation (RFA) of two idiopathic VOT tachycardias. During the sixth EPS, a proximal aortogram demonstrated a left aortic sinus of valsalva (LASV) aneurysm. Subsequntly, a novel and successful RFA strategy of aneurysm isolation was undertaken. The presence of multiple clinical or inducible VT morphologies and the characterization of a VT as re-entrant should raise concerns that a complex arrhythmogenic substrate is present and defining the anatomy with angiography or an alternative imaging modality is essential in achieving a successful ablation strategy.展开更多
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 t...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.展开更多
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 ar...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 be- cause of the technical difficulties associated with examining this theory. The L-type calcium current （/Ca-L）, an important in- ward 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 character- istics of the ICa-L in these myocytes. Rabbit RVOT and RV myocytes were isolated and their AP and Ic,-L were investigated us- ing 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 afterdepolariza- tion （EAD） and second plateau responses were seen in RVOT myocytes but not in RV myocytes. RVOT myocytes had a high- er current density for/Ca-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.展开更多
Background Studies on human, rat and chicken embryos have demonstrated that during the period of outflow tract septation, retraction of the distal myocardial margin of the outflow tract from the junction with aortic ...Background Studies on human, rat and chicken embryos have demonstrated that during the period of outflow tract septation, retraction of the distal myocardial margin of the outflow tract from the junction with aortic sac to the level of semilunar valves leads to the shortening of the myocardial tract. However, the mechanism is not clear. So we investigated the mechanism of outflow tract shortening and remodeling and the spatio-temporal distribution pattern of α-SMA positive cells in the outflow tract cushion during septation of the outflow tract in the embryonic mouse heart Methods Serial sections of mouse embryos from embryonic day 9 (ED 9) to embryonic day 16 (ED 16) were stained with monoclonal antibodies against α-SCA, α-SMA, or desmin, while apoptosis was assessed using the terminal deoxyribonucleotidy transferase-mediated dUTP-digoxigenin nick-end labeling (TUNEL) assay Results Between ED 11 and ED 12, the cardiomyocytes in the distal portion of the outflow tract were observed losing their myocardial phenotype without going into apoptosis, suggesting that trans-differentiation of cardiomyocytes into the cell components of the free walls of the intrapericardial ascending aorta and pulmonary trunk The accumulation of α-SMA positive cells in the cardiac jelly began on ED 10 and participated in the ridge fusion and septation of the outflow tract Fusion of the distal ridges resulted in the formation of the facing walls of the intrapericardial ascending aorta and pulmonary trunk Fusion of the proximal ridges was accompanied by the accumulation of α-SMA positive cells into a characteristic central whorl, in which cell apoptosis could be observed Subsequent myocardialization resulted in the formation of the partition between the subaortic and subpulmonary vestibules Conclusions The shortening of the embryonic heart outflow tract in mice may result not from apoptosis, but from the trans-differentiation of cells with cardiomyocyte phenotype in the distal portion of the outflow tract into the cell components of the free walls of the intrapericardial ascending aorta and pulmonary trunk The primary roles of α-SMA positive cells in the septation and remodeling of the outflow tract may assure proper fusion of the outflow ridges and form the facing walls of the intrapericardial ascending aorta and pulmonary trunk展开更多
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 ventricu...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.展开更多
Blood cyst is a rare primary cardiac tumor usually affecting the cardiac valves. Associated with severe occlusion-related complications, it is generally removed surgically. With a brief review of the literature, we pr...Blood cyst is a rare primary cardiac tumor usually affecting the cardiac valves. Associated with severe occlusion-related complications, it is generally removed surgically. With a brief review of the literature, we present a case of pedunculated tumor in the left ventricular outflow tract identified by echocardiography.展开更多
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 ventricula...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.展开更多
Hypertrophic cardiomyopathy (HCM), the most common single-gene cardiovascular disease, is associated with increased risk for arrhythmias, heart failure, and sudden cardiac death. The hemodynamic changes known to occur...Hypertrophic cardiomyopathy (HCM), the most common single-gene cardiovascular disease, is associated with increased risk for arrhythmias, heart failure, and sudden cardiac death. The hemodynamic changes known to occur during pregnancy can exacerbate heart failure and arrhythmias in women with HCM. We present a 30-year-old woman with HCM to illustrate the benefits of multidisciplinary team management of severe left ventricular outflow tract obstruction (peak gradient >100 mmHg) for optimal maternal and fetal outcomes.展开更多
基金This study was supported by the Pediatric Heart Center at Skåne University Hospital Lund and Lund University,and by the Swedish Children’s Heart Association.
文摘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.
基金supported by Zhangjiakou Project of Science and Technology Studies and Development Planning(Grand No.1321078D)
文摘Objective: To investigate the electrophysiological changes of autonomic cells in left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with chronic heart failure.Methods: Guinea pigs model of iron deficiency anemia complicated with chronic heart failure in 10 guinea pigs of the experimental group was made by feeding a low iron diet,pure water and subcutaneous injection of isoproterenol. The control group consisting of 11 guinea pigs was given normal food, normal water and injected with normal saline. The left ventricular outflow tract model specimen was also prepared. The standard microelectrode technique was used to observe electrophysiological changes of autonomic cells in the outflow tract of left ventricular heart failure complicated with iron deficiency anemia in guinea pig model. The indicators of observation were maximal diastolic potential, action potential amplitude, 0 phase maximal depolarization velocity, 4 phase automatic depolarization velocity, repolarization 50% and 90%, and spontaneous discharge frequency.Results: Compared with the control group, 4 phase automatic depolarization velocity,spontaneous discharge frequency and 0 phase maximal depolarization velocity decreased significantly(P < 0.01) and action potential amplitude reduced(P < 0.01) in model group. Moreover, repolarization 50% and 90% increased(P < 0.01).Conclusions: There are electrophysiological abnormalities of the left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with heart failure.
基金supported by Zhangjiakou Project of Science and Technology Studies and Development Planning(Grand No.1321078D)
文摘Objective: To investigate the electrophysiology effects and mechanism of iron overload on the slow response autorhythmic cells in the left ventricular outflow tract of guinea pigs.Methods: Standard microelectrode cell recording techniques were adopted to observe the electrophysiological effects of different concentrations of Fe^(2+)(100 μmol/L, 200 μmol/L) on the left ventricular outflow tract autorhythmic cells.Heart tissues were perfused with FeSO_4(200 μmol/L) combing with CaCl_2(4.2 mmol/L), Verapamil,(1 μmol/L), and nickel chloride(200μmol/L) respectively to observe the influences of these contents on electrophysiology of FeSO_4(200μmol/L) on the left ventricular outflow tract autorhythmic cells.Results: Fe^(2+)at both 100 μmol/L and 200 μmol/L could change the electrophysiological parameters of the slow response autorhythmic cells of the left ventricular outflow tract in a concentrationdependent manner resulting into decrease in Vmax, APA and MDP, slower RPF and VDD, and prolonged APD_(50) and APD_(90)(P all <0.05).Besides, perfusion of increased Ca^(2+) concentration could partially offset the electrophysiological effects of Fe^(2+)(200 μmol/L).The L-type calcium channel(LTCC) blocker Verapamil(1 μmol/L) could block the electrophysiological effects of Fe^(2+)(200 μmol/L).But the T-type calcium channel(TTCC) blocker nickel chloride(NiCl_2, 200 μmol/L) could not block the electrophysiological effects of Fe^(2+)(200 μmol/L).Conclusions: Fe^(2+) can directly change the electrophysiological characteristics of the slow response autorhythmic cells of the left ventricular outflow tract probably through the L-type calcium channel.
基金supported in part by grants from the Science and Technology Key Foundation of Guangdong Province(No.2010B031600166)the Science and Technology Foundation of Guangdong Province(No.2011B061300072)
文摘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.
文摘OBJECTIVE: To summarize the experience in modified reconstruction of the hepatic outflow tract during piggyback liver transplantation at our hospital. METHODS: The clinical data on 67 patients undergoing piggyback liver transplantation with modified hepatic outflow tract reconstruction from January 1999 to October 2002 were analyzed retrospectively. RESULTS: In this group, 7 patients (10. 45%) died perioperatively. Complications included: pulmonary infection (38 patients); multiple organ system failure (10), intraperitoneal bleeding (6), acute respiratory distress syndrome (14), thrombosis of the hepatie artery (1), and bile leakage (1). No hepatic outflow occluded. Two recipients survived for over 3 years, 8 over 2 years, and 19 over a year. CONCLUSION: Modified hepatic outflow reconstruction in piggyback live transplantation may increase the success rate of liver transplantation and decrease technical complications.
基金supported by a grant form a Program of Science and Technology Development of Hubei Province (2004AA304B09).
文摘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.
文摘Objective Right ventricular outflow tract septum has become widely used us an electrode placement site. However, data concerning lead performances and complications for lead repositioning with this technique were scant. The purpose of this study was to observe long- term lead performances and complications of right ventricular outflow tract septal pacing and provide evidences for choosing an optimal electrode implantation site. Methods Thirty-six patients with septal active electrode implantation and 39 with apical passive electrode implantation were enrolled in this study. Pacing threshold, R-wave sensing, lead impedance, pacing QRS width and pacing-related compli- cations for two groups at implantation and follow-up were compared. Results There were higher pacing threshold and shorter pacing QRS width at implantation in the septal group compared with the apical group. There were no differences between the septal and the apical groups in pacing threshold, R-wave sensitivity, lead impedance and pace-related complication during a follow-up. Conclusions Right ventricular outflow tract septum could be used as a first choice for implantation site because it had long-term stable lead performances and no serious complications compared with the traditional apical site.
文摘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.
文摘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.
文摘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.
文摘Idiopathic monomorphic ventricular tachycardia and premature ventricular complexes (PVCs) commonly arise from the right and left ventricular outflow tracts (VOT). Their mechanism is most commonly triggered activity from delayed after-depolarizations and successful ablation is performed at the site of earliest endocardial activation. Re-entrant mechanisms have been rarely described. We report a case of an otherwise healthy patient who ultimately underwent six electro-physiology studies (EPS) and suffered numerous implantable cardiac defibrillator (ICD) discharges prior to the successful radiofrequency ablation (RFA) of two idiopathic VOT tachycardias. During the sixth EPS, a proximal aortogram demonstrated a left aortic sinus of valsalva (LASV) aneurysm. Subsequntly, a novel and successful RFA strategy of aneurysm isolation was undertaken. The presence of multiple clinical or inducible VT morphologies and the characterization of a VT as re-entrant should raise concerns that a complex arrhythmogenic substrate is present and defining the anatomy with angiography or an alternative imaging modality is essential in achieving a successful ablation strategy.
文摘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.
文摘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 be- cause of the technical difficulties associated with examining this theory. The L-type calcium current （/Ca-L）, an important in- ward 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 character- istics of the ICa-L in these myocytes. Rabbit RVOT and RV myocytes were isolated and their AP and Ic,-L were investigated us- ing 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 afterdepolariza- tion （EAD） and second plateau responses were seen in RVOT myocytes but not in RV myocytes. RVOT myocytes had a high- er current density for/Ca-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.
基金ThisworkwassupportedbytheScientificResearchFoundationforReturnedOverseasChineseScholars,StateEducationMinistryandEducationMinistryofShanxiProvince (No 9845 )
文摘Background Studies on human, rat and chicken embryos have demonstrated that during the period of outflow tract septation, retraction of the distal myocardial margin of the outflow tract from the junction with aortic sac to the level of semilunar valves leads to the shortening of the myocardial tract. However, the mechanism is not clear. So we investigated the mechanism of outflow tract shortening and remodeling and the spatio-temporal distribution pattern of α-SMA positive cells in the outflow tract cushion during septation of the outflow tract in the embryonic mouse heart Methods Serial sections of mouse embryos from embryonic day 9 (ED 9) to embryonic day 16 (ED 16) were stained with monoclonal antibodies against α-SCA, α-SMA, or desmin, while apoptosis was assessed using the terminal deoxyribonucleotidy transferase-mediated dUTP-digoxigenin nick-end labeling (TUNEL) assay Results Between ED 11 and ED 12, the cardiomyocytes in the distal portion of the outflow tract were observed losing their myocardial phenotype without going into apoptosis, suggesting that trans-differentiation of cardiomyocytes into the cell components of the free walls of the intrapericardial ascending aorta and pulmonary trunk The accumulation of α-SMA positive cells in the cardiac jelly began on ED 10 and participated in the ridge fusion and septation of the outflow tract Fusion of the distal ridges resulted in the formation of the facing walls of the intrapericardial ascending aorta and pulmonary trunk Fusion of the proximal ridges was accompanied by the accumulation of α-SMA positive cells into a characteristic central whorl, in which cell apoptosis could be observed Subsequent myocardialization resulted in the formation of the partition between the subaortic and subpulmonary vestibules Conclusions The shortening of the embryonic heart outflow tract in mice may result not from apoptosis, but from the trans-differentiation of cells with cardiomyocyte phenotype in the distal portion of the outflow tract into the cell components of the free walls of the intrapericardial ascending aorta and pulmonary trunk The primary roles of α-SMA positive cells in the septation and remodeling of the outflow tract may assure proper fusion of the outflow ridges and form the facing walls of the intrapericardial ascending aorta and pulmonary trunk
文摘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.
文摘Blood cyst is a rare primary cardiac tumor usually affecting the cardiac valves. Associated with severe occlusion-related complications, it is generally removed surgically. With a brief review of the literature, we present a case of pedunculated tumor in the left ventricular outflow tract identified by echocardiography.
基金This work was supported by National Key R&D Program of China(No.2017YFC1308100)Beijing Municipal Science and Technology Commission(No.Z201100005520001).
文摘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.
文摘Hypertrophic cardiomyopathy (HCM), the most common single-gene cardiovascular disease, is associated with increased risk for arrhythmias, heart failure, and sudden cardiac death. The hemodynamic changes known to occur during pregnancy can exacerbate heart failure and arrhythmias in women with HCM. We present a 30-year-old woman with HCM to illustrate the benefits of multidisciplinary team management of severe left ventricular outflow tract obstruction (peak gradient >100 mmHg) for optimal maternal and fetal outcomes.
