Asthenia ; physiopathology ; Cyanosis ; physiopathology ; Expert Testimony ; Fatigue ; physiopathology ; Heart Defects, Congenital ; physiopathology ; Humans ; Walking

To investigate an association between surface electrocardiographic (ECG) parameters and sustained ventricular tachycardia (VT) in children after repair of congenital heart disease (CHD), data were obtained and analyzed in three groups (group I, 7 postoperative patients with episode of sustained VT (4 tetralogy of Fallot (TOF), 2 double outlet right ventricle (DORV), 1 truncus arteriosus); group II, 14 children with postoperative TOF not associated with VT; group III, 14 normal children). Mean age at the onset of sustained VT was 129+/-77 months (range 60-232); mean age at corrective surgery, 44+/-33 months (range 10-102); mean follow-up period after surgery, 84+/-74 months (range 20-185); the duration from repair to the onset of sustained VT, range 1-185 months. Compared to group II and III, group I showed longer QRS duration (group I, 137+/-10 msec; group II, 114+/-22 msec; group III, 65+/-12 msec) and shorter corrected J to Tmax interval (group I, 209+/-24 msec; group II, 272+/-44 msec; group III, 249+/-18 msec). QT and corrected QT, J to Tmax interval, and their dispersions in group I and II are significantly different from those of group III. In conclusion, QRS duration and corrected J to Tmax interval could be helpful to predict ventricular tachycardia in postoperative CHD.
Adolescence ; Child ; Child, Preschool ; Electrocardiography ; Female ; Heart Defects, Congenital/surgery* ; Heart Defects, Congenital/physiopathology ; Human ; Infant ; Male ; Tachycardia, Ventricular/etiology*

OBJECTIVETo establish an animal model of congenital heart defect with decreased pulmonary blood flow for better understanding the pathophysiology of pulmonary vascular development and related regulatory mechanisms of congenital heart defect with decreased pulmonary blood flow.

METHODOne to two months old pigs were randomly divided into three groups: control group (group C, n = 6) with right chest small incisions induced transient pulmonary blood reduction; light-moderate stenosis groups (group T(1), n = 7): artificial atrial septum defect (ASD) plus controlled pulmonary artery banding to generate a systolic pressure gradient of 20 - 30 mm Hg (1 mm Hg = 0.133 kPa); severe stenosis groups (group T(2), n = 7): similar surgical procedures as group T(1), and controlled pulmonary artery banding to generate a systolic pressure gradient ≥ 30 - 50 mm Hg. 64-slice computed tomography scanning was performed at one month post operation. Arterial blood gas analysis, hemoglobin value, pulmonary vessel, ASD and banding ring diameters and trans-pulmonary artery banding pressure (Trans-PABP) were determined at two months post operation.

RESULTSOne pig died due to tracheal intubation accident in the C group, one pig died due to bowel obstruction in the T(1) group and two pigs died due to acute right heart failure and chronic heart failure respectively in T(2) group. 64-slice CT angiography results showed that aortic diameter of T(1) group was significantly lower than that of C group and banding diameter was significantly lower than aortic diameter in the T(1) and T(2) groups at one month post operation. Two months after operation, the size of ASD were (8.0 ± 0.5) mm and (8.9 ± 1.4) mm (P > 0.05) respectively in the T(1) and T(2) groups after operation. The Trans-PABP was significantly higher in the T(1) and T(2) groups than in C group (P < 0.01), and the Trans-PABP was significantly higher in the T(2) group than in T(1) group (P < 0.01). PaO2 and SaO2 in the T(1) and T(2) groups were significantly lower than those in C group.

CONCLUSIONArtificial atrial septum defect combined pulmonary artery banding procedures could be successfully used to establish model of congenital heart defect with decreased pulmonary blood flow and this model could help to understand the pathophysiology and monitor therapy efficacy for patients with congenital heart defect with decreased pulmonary blood flow.

Animals ; Disease Models, Animal ; Heart Defects, Congenital ; physiopathology ; Lung ; blood supply ; Pulmonary Artery ; physiopathology ; Pulmonary Circulation ; Pulmonary Veins ; physiopathology ; Swine

OBJECTIVEThis review aims to provide an overview of conventional and novel indices used in clinical and research arenas for evaluation of right ventricular (RV) function in congenital heart diseases with a dual-chambered circulation.

DATA SOURCESArticles cited in this review were selected using PubMed search of publications in English with no date limits. The search terms included "echocardiography", "right ventricle", "RV function", "cardiac function", and "congenital heart disease". Key references were also searched for additional publications.

STUDY SELECTIONArticles related to description of echocardiographic techniques in the evaluation of subpulmonary or systemic RV function and their applications in congenital cardiac malformations were retrieved and reviewed.

RESULTSThree approaches have been used to evaluate subpulmonary and systemic RV function: (1) assessment of changes in RV size in the cardiac cycle, (2) determination of Doppler-derived velocities and systolic and diastolic time intervals, and (3) quantification of myocardial velocities and deformation.

CONCLUSIONSConventional and novel echocardiographic techniques enable the evaluation of subpulmonary and systemic RV function. Novel echocardiographic techniques have further allowed quantification of RV volumes and direct interrogation of myocardial deformation. These new techniques show promise in a more comprehensive evaluation beyond "eye-balling" of RV function in the growing population of adolescent and adult congenital heart patients.

Echocardiography ; methods ; Heart Defects, Congenital ; diagnosis ; physiopathology ; Humans ; Ventricular Function, Right ; physiology

OBJECTIVENeurally adjusted ventilatory assist (NAVA) is a new mode of mechanical ventilation that delivers ventilatory assist in proportion to neural effort. This study aimed to compare the hemodynamic safety, oxygenation and gas exchange effects ventilated with NAVA and with pressure support ventilation (PSV) in infants who underwent open-heart surgery.

METHODSTwenty-one infants who underwent open-heart surgery for congenital heart disease (mean age 2.9+/- 2.1 months and mean weight 4.2+/- 1.4 kg) were enrolled. They were ventilated with PSV and NAVA for 60 minutes respectively in a randomized order. The hemodynamic, oxygenation and gas exchange effects produced by the two ventilation modes were compared.

RESULTSThree cases failed to shift to NAVA because of the bilateral diaphragmatic paralysis after operation. In the other 18 cases, there were no significant differences in the heart rate (HR), systolic blood pressure (BPs) and central venous pressure (CVP) in the two ventilation modes. The PaO2/FiO2 (P/F) ratio in NAVA was slightly higher than in PSV, but there was no statistical difference. PaCO2 did not show significant differences in the two modes. The peak inspiratory pressure (PIP) and electrical activity of the diaphragm (EAdi) in NAVA were significantly lower than in PSV. The EAdi signal after extubation was higher in infants who needed reintubation or intervention of noninvasive mechanical ventilation than in those who were extubated successfully (30.0+/- 8.4 microV vs 11.1+/- 3.6 microV; P<0.01).

CONCLUSIONSAs the first study of application of NAVA in infants in China, this study shows that NAVA has the same homodynamic effects as PSV. However the PIP for maintaining the same level of PaCO2 in NAVA is significantly lower than that in the traditional PSV. Monitoring the EAdi signal after extubation may show the risks of reintubation or intervention of noninvasive mechanical ventilation.

Female ; Heart Defects, Congenital ; physiopathology ; surgery ; Hemodynamics ; Humans ; Infant ; Male ; Respiration, Artificial ; methods

The hemodynamic findings related to the histologic changes in the small pulmonary arteries in congenital heart disease were analyzed with a left-to-right shunt. A lung biopsy was performed during the repair because of pulmonary arterial (PA) hypertension (mean PA pressure > or = 15 mmHg) in 38 patients. There were 13 patients whose age ranged from 2 years to 25 years old. A preoperative cardiac catheterization was performed to locate the site of the defect and to determine the preoperative hemodynamic findings. Among them, 29 patients had pulmonary vascular resistance (PVR) > 2.5 unit/m2. The lung biopsy specimens were investigated microscopically for the Heath- Edward grade, morphometric analysis of medial wall thickness (MWT) and the rate of the decrease in the pulmonary arteriolar concentration (PAC) obtained by the alvoelo-arterial ratio divided by patients' age. All patients were in the Heath-Edward grade I to III (29 patients in grade I). This grade correlated with the MWT, but did not correlate with a decrease in the PAC. The MWT and the rate of the decrease in the PAC did not accompany each other, but either one had the tendency dominate the pattern in individual patients. The MWT had a close correlation with the mean PA pressure and PVR, and an even closer correlation in patients with a high PVR and those older than 2 years of age. The rate of the decreased in the PAC showed a weak correlation with the shunt volume in patients over 2 years of age or with a large shunt. In the high flow group (PVR < 2.5 unit/m2, Qp/Qs > 2.0, n=14) the MWT was significantly thinner and the rate of the decrease in the PAC was significantly higher than the high resistance group (PVR > 2.5 unit/m2, Qp/Qs2 < 2.0, n=13). The rate of the decrease in the PAC correlated with the patients' age, but the MWT did not. The lung biopsy results in patients who had both left-to-right shunts and pulmonary hypertension showed that the rate of the decrease in the PAC was weakly related to the shunt volume and the MWT was related to the PA pressure and PVR. Either an increased MWT or the rate of the decrease in the PAC tended to dominate. These phenomena were prominent in patients older than 2 in whom a wide range of individual variations were noted in the morphometric pattern. The medial hypertrophy and the rate of the decrease in the PAC may be induced by different stimuli or that medial hypertrophy may play a role in preventing PAC decrease.
Adolescent ; Adult ; Child ; Child, Preschool ; Female ; Heart Defects, Congenital/*pathology/physiopathology/surgery ; Hemodynamics ; Human ; Infant ; Male ; Pulmonary Artery/*pathology/physiopathology

OBJECTIVETo compare the effects of conventional ultrafiltration and modified ultrafiltration in protecting patients' pulmonary function during cardiopulmonary bypass.

METHODSThirty infants patients (less than 7 kg) were divided into two groups: conventional ultrafiltration group (CUF, n = 15) and modified ultrafiltration group (MUF, n = 15). The volume of ultrafiltration, transfusion, hematocrit (HCT) before and after ultrafiltration, patients' respiration function (respiration index, A-aDO2, airway pressure), the time of mechanical ventilation and ICU in the two groups were respectively monitored.

RESULTSThe transfusion in MUF group was significantly less than in CUF group (P < 0.01), and the volume of ultrafiltration in MUF group was significantly more than in CUF group (P < 0.01). The time of mechanical ventilation and ICU staying in MUF group were significantly shorter in MUF group than that in CUF group (P < 0.05). At 12 and 24 hours after operations, the A-aDO2 in MUF group was lower than that in CUF group (P < 0.05), and the respiratory index in MUF group was higher than that in CUF group (P < 0.05).

CONCLUSIONThe modified ultrafiltration can effectively improve pulmonary function after operations for low weight infants.

Cardiopulmonary Bypass ; Female ; Heart Defects, Congenital ; physiopathology ; surgery ; Humans ; Infant ; Lung ; physiopathology ; Male ; Respiratory Function Tests ; Ultrafiltration ; methods

OBJECTIVETo investigate the relationship between pulmonary pathological features and clinical physiology of congenital heart defects (CHD) with decreased pulmonary artery blood flow.

METHODSBetween July 2001 and May 2006, 18 patients with CHD with decreased pulmonary artery blood flow undergoing palliative or definitive repair and having lung biopsy intraoperatively were enrolled in this study. The patients' age was 0.4 - 8.0 years, and body weight was 6.0 - 20.0 kg. The method of semi-quantitative morphometric technique and an image analyzer were applied to measure the following indices of pulmonary microvessels: the percentage of media thickness (MT%), the percentage of media section area (MS%) and numbers of microvessels per square centimeter (VPSC). The diameters of left pulmonary artery (LPA) and right pulmonary artery (RPA) were measured with two-dimensional echocardiography. The percutaneous oxygen saturation (SpO(2)), hemoglobin concentration (HB) and hematocrit value (HCT) were examined and recorded preoperatively.

RESULTSThere was a significant negative correlation between SpO(2) and HCT or Hb (R(2) = 0.4914, P = 0.001 and R(2) = 0.5505, P < 0.001), the variation trend of these three variables was linked. There was a negative correlation between SpO(2) and the body weight (R(2) = 0.2208, P = 0.049), which is in accordance with clinical features of aggravated process of cyanosis and hypoxia. The morphological observation of lung biopsy specimens indicated that most of peripheral pulmonary arteries were distended, irregular and their walls were uneven, and "lake" type of pulmonary AV malformations were observed. There was a positive correlation between VPSC and the body weight or BSA (R(2) = 0.5472, P < 0.001 and R(2) = 0.5233, P = 0.001). There was a significant correlation between VPSC and LPA or RPA (R(2) = 0.4312, P = 0.003 and R(2) = 0.2463, P = 0.036). It was shown that the diameter of central pulmonary arteries could be a reflection of peripheral pulmonary artery growth. The diameter of LPA also correlated with the diameter of RPA (R(2) = 0.286, P = 0.022).

CONCLUSIONSFor patients with congenital heart defects with decreased pulmonary blood flow, the pulmonary pathological changes are the bases of their clinical physiologic features. It is suggested that they should be treated in their earlier stage of life.

Child ; Child, Preschool ; Female ; Heart Defects, Congenital ; pathology ; physiopathology ; Humans ; Infant ; Lung ; blood supply ; Male ; Pulmonary Artery ; abnormalities ; pathology ; physiopathology

BACKGROUNDThe fenestration function is by allowing a right-to-left shunt resulting in an increased cardiac index, associated with mild arterial oxygen desaturation. Subsequent transcatheter fenestration closure can be performed after haemodynamic assessment. The purpose of this study was to compare the outcomes of extracardiac connection (EC) with or without fenestration.

METHODSNinety-five consecutive patients diagnosed with univentricular heart disease underwent EC using Gore-Tax conduits at the Department of Children's Heart Center, Justus-Liebig-University Giessen Germany from June 1996 to July 2007. According to EC with or without fenestration, the patients were assigned to two groups (group A with fenestration and group B without fenestration). Mortality, effusions, postoperative mean pulmonary artery pressure, postoperative oxygen saturation, postoperative thrombosis, postoperative neurological problems, and the postoperative loss of sinus rhythm were compared. In group A, 23 patients had fenestration closed interventionally after a mean time of 20-22 months.

RESULTSMortality and postoperative mean pulmonary artery pressure in group B (3 and (15.1 +/- 3.4) mmHg, respectively) were significantly higher than group A (0 and (13.2 +/- 2.8) mmHg, respectively). Postoperative oxygen saturation, postoperative thrombosis, postoperative neurological problems, and the postoperative loss of sinus rhythm did not differ between cohorts.

CONCLUSIONSFenestrating an extracardiac tunnel seems to improve acute postoperative mortality by rising cardiac output. The induced right-to-left shunt shows no morbidity postoperatively. If a stabilized chronic hemodynamic situation is achieved, an interventional closure of the fenestration can be performed to advance the arterial saturation and improve the exercise tolerance of the patients.

Adolescent ; Child ; Child, Preschool ; Fontan Procedure ; adverse effects ; methods ; mortality ; Heart Defects, Congenital ; physiopathology ; surgery ; Humans ; Infant ; Pulmonary Artery ; physiopathology

During cardiac catheterizations in 20 cases with congenital heart disease, intracardiac shunts were measured by two methods, dye dilution method and the Fick method, and the results were compared. Arterial dilution curves were used for the estimation of both the right-to-left and left-to-right shunts-Venous dilution curves were used for measurement of left-to-right shunts. In cases with a left-to-right shunt, the amount of the shunt was expressed as per cent of total pulmonary blood flow and, in cases with a right-to-left shunt, as per cent of total systemic blood flow. The following results were obtained. 1. In 8 cases with a right-to-left shunt, the amount of the shunt was 35.6 +/-18.1% by the Fick method and 34.0 +/-19.2% by arterial dilution curves. The difference was not statistically significant(p> 0.l). In 15 cases with a left-to-right shunt, the amount of shunt was 41.3 +/-26.6% by the arterial dilution curve and 36.6 +/-14.O% by the Fick method. The difference was not statistically significant(p> 0.1). Also venous dilution curve was performed in 8 cases of left-to-right shunt and the amount of the shunt was 33.0 +/-21.0%, as compared to 35.5 +/-17.3% by the Fick methods. The difference was not statistically significant (p> 0.1). 2. Arterial dilution curves could be used to localize right-to-left shunts and venous dilution curves left-to-right shunts, whereas tile Fick method was helpful only for the localization of left-to-right shunts. 3. It was possible to detect small left-to-right (less than 10%) and right-to-left (less than 5%) shunts by dye dilution curves, which was not possible with the Fick method. 4. In detection of small intracardiac shunts as well as in shunt localization, the dye dilution method was more accurate than the Fick method. The difference of the amount of the shunt estimated by the two methods was not statistically significant.
Adolescent ; Adult ; Cardiac Output ; Child ; Child, Preschool ; Dye Dilution Technique ; Female ; Heart Defects, Congenital/*physiopathology ; *Heart Function Tests ; Human ; Male