Strain and Strain Rate To Evaluate Right Heart Function of Ebstein Anomaly (EA) Patients Before and After Operation.

OBJECTIVE: This study was aimed to elucidate the feasibility of using right ventricular (RV) strain and strain rate to evaluate right heart function of Ebstein anomaly (EA) patients before and after operation. METHODS: Sixty EA patients and 30 healthy controls underwent echocardiography (UCG) for evaluation of right heart function. Preoperative UCG and 1-week and 3-month postoperative UCG were performed in EA patients. RV strain and strain rate were measured on the four-chamber section of tissue Doppler imaging (TDI). RESULTS: The strain and strain rate representative of right ventricle systolic function were reduced prior to operation. RV strain and strain rate improved after the operation (P < .001), most significantly in the basal segment and middle segment of the free wall of the right ventricle as well as the basal segment of the interventricular septum (P < .001). CONCLUSIONS: The measurement of RV strain and strain rate on tissue Doppler imaging can be employed to assess the preoperative and postoperative RV function, proves the positive effect of tricuspid valve repair on right heart function, and offers more insight on right heart function evaluation.

Emergency Pacing via the Umbilical Vein and Subsequent Permanent Pacemaker Implantation in a Neonate.

A dying neonate with congenital complete atrioventricular block underwent an emergency temporary pacing via the umbilical vein 1 h after birth. Implantation of a permanent epicardial pacemaker system was performed at the age of 10 days. During the follow-up period of 3 months, the child had been growing well with the VVIR pacemaker.

[Clinical study of anticoagulation with warfarin and heparin in patients after mechanical valve replacement].

OBJECTIVE: To investigate the effect of different methods of anticoagulation after mechanical valve replacement. METHODS: Totally 172 cases of mechanical valve replacement performed from October 2005 to June 2008 were divided into two groups and then analyzed retrospectively. Patients on warfarin and heparin were classified as the heparin group while those on warfarin alone were classified as the warfarin group. The operation, anticoagulation, anticoagulation index and associated complications were recorded to compare the effect of anticoagulation between two groups. RESULTS: warfarin group: the overall anticoagulation effect was satisfactory except for cerebral embolism (n=1, 1.1%) and lower gastrointestinal hemorrhage (n=1, 1.1%) during hospitalization. Heparin group: no anticoagulation-related complication was found. The time to reach stable warfarin anticoagulation was shorter than the warfarin group and difference was of significance (8 d±3 d vs 11 d±4 d, P<0.01). After adjustment of potential confounding factors such as age, gender, weight by linear regression analysis, the result showed that, the time to reach stable warfarin anticoagulation was shortened than the warfarin group by 2.11 days. Statistical significance of difference was observed between two groups (P<0.01). CONCLUSION: It is both safe and effective to anticoagulated the patients after mechanical valve replacement with warfarin and heparin.

[One-stage repair of congenital aortic arch disease with other cardiac defects by using autologous pulmonary artery tissue].

OBJECTIVE: To analyze the surgical strategy and result of one-stage repair for congenital aortic arch disease associated with other cardiac anomalies. METHODS: Between April 1993 and November 2009, 25 consecutive patients aged 26 d to 6.5 years underwent one-stage repair for congenital aortic arch disease with other cardiac anomalies. Among them, 6 patients had coarctation of aorta, 6 patients had interrupted aortic arch, and 13 cases had hypoplasia of aortic arch. The surgical techniques include excision of the anterior wall of pulmonary artery, resection of patent ductus arteriosus tissue, aortic arch reconstruction with autologous pulmonary artery wall, reconstruction of the pulmonary artery and repair of the associated defects. RESULTS: Twenty-four patients survived and recovered uneventfully. One patient died of pulmonary hypertension crisis in hospital. The reconstruction of the aorta and the correction of the intracardiac anomalies were proved by postoperative echocardiography and CT scan. There were no neurological or other complications. The follow-up showed that all patients developed normally and there were no restenosis of the aorta arch. CONCLUSIONS: With the benefits of growth potential and less tension, autologous pulmonary artery tissue is an optimal choice in aortic arch reconstruction. One-stage repair of congenital aortic arch disease associated with other cardiac anomalies can achieve good results.

[Staged total cavopulmonary connection for complex congenital heart diseases].

OBJECTIVE: To review the experience of staged total cavopulmonary connection (TCPC) in complex congenital heart diseases. METHODS: From June 1998 to March 2008, 22 patients underwent staged TCPC for complex congenital heart diseases. Among them, 9 were univentricular and pulmonary artery valve stenosis; 3 were univentricular and pulmonary artery atresia; 1 was transposition of great arteries, crisscross heart and pulmonary artery valve stenosis; 1 was complete atrioventricular canal defects, left ventricular hypoplasia, pulmonary artery atresia and atrioventricular valvular regurgitation; 1 was complete atrioventricular canal defects, left ventricular hypoplasia, pulmonary artery valve stenosis and atrioventricular valvular regurgitation after Glenn procedure; 1 was mirror image dextrocardia, single ventricle, pulmonary artery atresia, major aortopulmonary collateral arteries (MAPCAs) and right pulmonary arteriovenous fistula after Glenn procedure; 4 were tricuspid atresia and pulmonary artery valve stenosis; 1 was tricuspid atresia and pulmonary atresia; 1 was mirror image dextrocardia, double-outlet of right ventricle, left ventricular hypoplasia, pulmonary artery valve stenosis, tricuspid incompetence, and MAPCAs. Among them, 5 patients received systemic-to-pulmonary artery shunt, bidirectional Glenn procedure and TCPC. Seventeen patients received bidirectional Glenn procedure, the mean age was (5.9+/-4.4) years old. Pulmonary artery pressure pre-Glenn procedure was 17 to 20 mm Hg (1 mm Hg=0.133 kPa). Atrioventricular valve incompetence in 3 patients. Nakata index was less than 200 mm2/m2 in 4 patients before the first stage operation. The age of TCPC procedure was (9.6+/-4.9) years old, the interval time was (3.7+/-1.2) years. RESULTS: There was one in-hospital death, the mortality was 4.5%. The patient with univentricular and pulmonary atresia, received systemic-to-pulmonary artery shunt, bidirectional Glenn procedure and TCPC and died of pneumorrhagia. Other patients were recovered well, postoperative central venous pressure was 12 to 18 mm Hg, percutaneous oxygen saturation was 90% to 96%. The cardiac function were in NYHA class I to II. CONCLUSIONS: The staged TCPC was a good procedure in high-risk Fontan candidates. The results were satisfactory for those patients. This staged strategy may extend the operative indications for the Fontan procedure.

[Coronary artery bypass grafting in patients over 70 years old].

OBJECTIVE: To retrospectively analyze the experiences, indications, technique, and results of coronary artery bypass grafting (CABG) in patients over 70 years old. METHODS: Ninety-one patients received coronary artery bypass grafting from March 2004 to March 2008. Ages ranged from 70 to 83 years old, 22 patients over 75 years old. Conventional CABG (CCABG) in 72 patients, off-pump CABG (OPCAB) in 19 patients. Clinical data has no significant differences in two groups. The rate of using left internal mammary artery was 96.7%. The number of grafts in CCABG and OPCAB group were 2 to 5 (3.5 +/- 0.8) and 1 to 4 (2.9 +/- 0.7) respectively. RESULTS: In-hospital death in 2 cases, both were from chronic obstructive pulmonary disease and pulmonary infection. Cerebral infarction in 1 case and pulmonary infection in 2 cases in CCABG group, but no significant difference between two groups, and no difference in intubation, ICU stay, respiratory failure, renal function failure. But number of grafts in CCABG was significantly more than that in OPCAB (P < 0.01). Postoperative follow-up was 3 to 36 months, 1 case with recurrent angina in OPCAB. CONCLUSIONS: According to the characteristic of coronary artery disease in elderly, fully revascularization and improving myocardial blood supply, patients over 70 years old with CABG can obtain the same efficacy as younger patients. There were not significant difference between CCABG and OPCAB.

Identification and compensation of quadratic terms of a space electrostatic accelerometer.

The ultra-sensitive space electrostatic accelerometers have been successfully employed in the Earth's gravity field recovery missions and the space gravitational experiments. Since the accelerometer output in the measurement bandwidth can be influenced by the orbital high-frequency disturbances due to the second-order nonlinearity effects, the relevant quadratic term must be accurately compensated to guarantee the accuracy of the electrostatic accelerometer. In this paper, three sources of the quadratic term are studied and formulated. They are the offset of the test mass in the housing due to the bias of the capacitive position transducer, the asymmetry of the electrode area, and the asymmetry of the actuation electronics. Two feasible compensation methods and an identification means are proposed. Compensation is achieved by adjusting the test mass actual working position or the asymmetry factor of the feedback actuation voltage. Identification is conducted by applying a periodic high frequency signal on the electrodes. Finally, the proposed methods are demonstrated, in view of future space applications, by suspending the accelerometer test mass on a torsion pendulum.

[Surgical treatment of complex congenital heart diseases with extracardiac conduit total cavopulmonary connection].

OBJECTIVE: To report the experience of extracardiac conduit total cavopulmonary connection (ECTCPC) in surgical treatment of complex congenital heart diseases. METHODS: From 1998 to 2006, 68 patients underwent ECTCPC for complex congenital heart diseases. Among them, 45 had functional univentricle with transposition of the great artery (TGA) and pulmonary artery valve stenosis, 19 had tricuspid atresia with hypoplasia of right ventricle, 4 had Ebstein's anomaly with hypoplasia of right ventricle. Six had left superior vena cava, 18 had received Bidirectional Glenn operation; Fifty-seven cases were performed under cardiopulmonary bypass with general anesthesia and hypothermia, 11 cases were performed without cardiopulmonary bypass. RESULTS: There were two death, the mortality was 2.9%. All patients were followed up from 1 to 8 years with no clinical symptoms and have been doing well. The arterial oxygen saturation was 90% - 96%, the cardiac function were in NYHA class I - II. CONCLUSION: The extra cardiac conduit TCPC is a simple procedure and superior to other type of Fontan procedure in most patients.

Surgical Treatment of Double Outlet Right Ventricle Complicated by Pulmonary Hypertension.

BACKGROUND: Double outlet right ventricle (DORV) is a group of complex congenital heart abnormalities. Preoperative pulmonary hypertension (PH) is considered an important risk factor for early death during the surgical treatment of DORV. The aim of this study was to report our experience on surgical treatment of DORV complicated by PH. METHODS: From June 2004 to November 2016, 61 patients (36 males and 25 females) aged 2 weeks to 26 years (median: 0.67 years and interquartile range: 0.42-1.67 years) with DORV (two great arteries overriding at least 50%) complicated by PH underwent surgical treatment in our center. All patients were categorized according to surgical age and lesion type, respectively. Pulmonary artery systolic pressure (PASP), pulmonary artery diastolic pressure (PADP), and mean pulmonary artery pressure (mPAP) were measured directly before cardiopulmonary bypass (CPB) was established and after CPB was removed. An intracardiac channel procedure was performed in 37 patients, arterial switch procedure in 19 patients, Rastelli procedure in three patient, Senning procedure in one patients, and Mustard procedure in one patient. The Student's t-test and Chi-squared test were performed to evaluate clinical outcomes of the surgical timing and operation choice. RESULTS: Fifty-five patients had uneventful recovery. PASP fell from 55.3 ± 11.2 mmHg to 34.7 ± 11.6 mmHg (t = 14.05, P < 0.001), PADP fell from 29.7 ± 12.5 mmHg to 18.6 ± 7.9 mmHg (t = 7.39, P < 0.001), and mPAP fell from 40.3 ± 10.6 mmHg to 25.7 ± 8.3 mmHg (t = 11.85, P < 0.001). Six (9.8%) patients died owing to complications including low cardiac output syndrome in two patients, respiratory failure in two, pulmonary hemorrhage in one, and sudden death in one patient. Pulmonary artery pressure (PAP) dropped significantly in infant and child patients. Mortality of both infants (13.9%) and adults (33.3%) was high. CONCLUSIONS: PAP of patients with DORV complicated by PH can be expected to fall significantly after surgery. An arterial switch procedure can achieve excellent results in patients with transposition of the great arteries type. Higher incidence of complications may occur in patients with ventricular septal defect (VSD) type before 1 year of age. For those with remote VSD type, VSD enlargement and right ventricle outflow tract reconstruction are usually required with acceptable results. The degree of aortic overriding does not influence surgical outcome.

[Left atrial and ventricular epicardial dual chamber pacing through a left lateral thoracotomy to treat pediatric complete atrioventricular block].

OBJECTIVE: To investigate the feasibility, advantages and efficacy of implantation of left atrial and ventricular epicardial dual chamber pacemaker to treat pediatric complete atrioventricular block. METHOD: Eleven children with median age 4.0 years (0.5-7.6 years) diagnosed as complete atrioventricular block resisting to drug therapy received implantations of left atrial and ventricular epicardial dual chamber pacemakers. Six were male and five female. Temporal or permanent right ventricular pacing was used for all of them before implantation of left atrial and ventricular epicardial dual chamber pacemakers. Three cases showed cardiac dysfunction. Left lateral thoracotomy was performed at 4th intercoastal space along anterior axillary line under general anesthesia, the pericardium was incised vertically anterior to the phrenic nerve, two pacing leads were individually located at left atrial appendage and left ventricular lateral wall. After all the parameters were detected to be satisfactory, a pouch was made at left abdomen under coastal margin. Dual chamber pacemaker was connected with pacing leads through subcutaneous tunnels. The sizes of heart chambers, cardiac functions, parameters of pacemaker, sensitivity, pacing status, PR interval and QRS interval were closely followed up post-operatively. RESULT: Implantations of pacemakers were successful for all of the patients with no complications associated with operations. Preoperative electrocardiograms showed QRS interval (180 ± 33)ms under right ventricular pacing, it decreased to (140 ± 24)ms after implantation of left atrial and ventricular epicardial dual chamber pacemaker, significantly lower than right ventricular pacing (t = 8.8, P < 0.05) . Atrioventricular (AV) interval was set at 90 ms, PR interval (124 ± 4)ms. Echocardiograms performed within 2-3 days after implantation of left atrial and ventricular epicardial dual chamber pacemakers showed that for the 3 cases who were previously under right atrial and right ventricular dual chamber pacing presenting cardiac dysfunction, their left ventricular diastolic diameter (LVDd) decreased from (46.3 ± 12.5) (32.0-55.0) ms to (44.7 ± 12.0) (31.0-53.0) mm and left ventricular ejection fraction (LVEF) increased from 30% ± 15% (18%-47%) to 44% ± 18% (33%-65%). During 2-14 months' follow up, LVEF increased progressively which became significantly higher than before (65% ± 8% vs. 30% ± 15%, t = 5.6, P < 0.05) . Cardiac chamber sizes and left ventricular systolic function for the other 8 patients maintain normal during follow up. Pacing status and sensitivity were satisfactory for all these patients during follow up. CONCLUSION: Implantation of left atrial and ventricular epicardial pacemaker might be considered for children diagnosed as complete atrioventricular block for whom endocardial pacemaker could not be implanted, due to its utmost protection for cardiac function with minimal injury and its ability to prevent or reverse pacemaker syndrome. Left atrial and left ventricular epicardium should be regarded as the first-choice and routine locations for epicardial pacing.