Arginine vasopressin to manage hypoxemic infants after stage I palliation of single ventricle lesions

OBJECTIVE: Management of patients with single ventricle physiology following stage I palliation procedures is often challenging, with optimization of the ratio of pulmonary-to-systemic blood flow as an important goal. Persistent hypoxemia may be a manifestation of elevated pulmonary vascular resistance and therefore decreased blood flow to the lungs. In such situations, the use of arginine vasopressin to increase systemic vascular resistance may be an effective strategy to improve pulmonary blood flow and maintain adequate pulmonary-to-systemic blood flow ratio. We describe three infants in whom persistent hypoxemia improved after institution of arginine vasopressin. DESIGN: Retrospective chart review. SETTING: Twenty-four bed medical-surgical pediatric intensive care unit at a large tertiary care academic hospital. PATIENTS: Three neonates with single ventricle physiology who received arginine vasopressin in the setting of hypoxemia following stage I palliation. RESULTS: Arginine vasopressin was initiated in all three patients for hypoxemia with a goal to increase systemic vascular resistance and generate a higher driving pressure for pulmonary blood flow. Twelve hours after arginine vasopressin initiation, systemic arterial saturation as determined by pulse oximetry and blood pressure increased, whereas heart rate, inotrope score, and Fio2 decreased in all three patients. Urine output was maintained and arterial lactate decreased during this time. Pulmonary-to-systemic flow ratio increased in one patient in whom it could be determined. CONCLUSION: In patients with single ventricle physiology and persistent hypoxemia following stage I palliation, administration of arginine vasopressin could improve oxygenation possibly by increasing systemic vascular resistance and therefore the pulmonary blood flow.     

Cerebral Hemodynamics in the Presence of Decreased Systemic Venous Compliance in Patients with Fontan Physiology May Limit Anaerobic Exercise Capacity

Patients who have had the Fontan procedure report poor exercise performance. Fontan subjects can tolerate a higher level of sub maximal activity than might be anticipated from Vo ₂, suggesting a different mechanism of exercise limitation. Near-infrared spectroscopy (NIRS) provides a non-invasive, continuous method to monitor regional tissue oxygenation (rSO2) and thereby a window into regional oxygen supply–demand relationships. We hypothesized that Fontan patients would have altered rSO2 trends from normal population that might reflect the mechanisms of exercise limitation. All the patients without structural or acquired heart disease and Fontan patients were eligible for inclusion if they were ordered to undergo cardiopulmonary exercise testing (CPET). Four-site regional rSO2 were recorded continuously during exercise. The difference between the oxyhemoglobin saturation measured by pulse oximetry (Spo ₂) and NIRS (rSO2) was computed as the regional arterial–venous saturation difference (AVDO2). A total of 33 normal subjects and five Fontan subjects scheduled for CPET were recruited. None of the Fontan subjects had a fenestration of the conduit. In the cerebral circulation, the Fontan patients have a significantly higher initial slope of increasing AVDO2 compared with normals. After vAT, the AVDO2 slope is flat for Fontan patients (p = 0.02). There is also a substantially larger rebound of cerebral rSO2 than in normal subjects after QT (p < 0.0001). Reduced anaerobic exercise capacity in Fontan patients may be secondary to limitation of cerebral blood flow, secondary to low systemic venous compliance due to absence of a sub-pulmonary ventricle, and augmented hyperventilatory response during exercise.     

The clinical utility of pulse oximetry in the pediatric emergency department setting.

Pulse oximetry provides a noninvasive, painless, accurate, and rapid method for measuring arterial oxygen saturation (SaO2). It has been shown to be valuable in anesthesia and critical care and recently has been used extensively in the outpatient setting. As is often the case with new technologies, little has been published on the basic issues of reliability, reproducibility, and effect on patient care. This prospective clinical study evaluated the basic principles of pulse oximetry in the pediatric emergency department setting and tested the hypotheses that pulse oximetry SaO2 measurements are reliable and provide valuable information, in addition to clinical and laboratory data which affect patient assessment and management. One hundred twenty patients were enrolled in phase 1 and 437 in phase 2 of the study. Pulse oximetry readings were reproducible with an intraclass correlation of 0.87. SaO2 measurements changed the assessed degree of illness in 188 (53%) patients; 47 (13%) were felt to be more ill and 130 (37%) to be less ill than at initial assessment. Sixty-nine (17%) patients were identified in whom SaO2 readings changed management plans; 27 (8%) were managed more aggressively (intubation, surgery, or admission), while 40 (11%) were managed less aggressively (discharged). In three cases, pulse oximetry was instrumental in the diagnosis of a serious illness. The results from this study indicate that pulse oximetry SaO2 readings are stable and reproducible and provide information which impacts significantly on patient assessment and management.     

Pulse oximetry is a poor predictor of hypoxemia in stable children with sickle cell disease

OBJECTIVE: To evaluate the accuracy of the pulse oximeter to detect hypoxemia in patients with sickle cell disease in an ambulatory care setting. STUDY DESIGN: Simultaneous measurements of PaO(2), arterial oxygen saturation by co-oximetry (criterion standard), and pulse oximetry were performed in 21 children with sickle cell disease during 22 outpatient visits. The bias and precision of the pulse oximeter compared with measured arterial oxygen saturation by co-oximetry were determined. The sensitivity, specificity, and positive and negative predictive values of the pulse oximeter to detect hypoxemia (PaO(2) <70 mm Hg) were also calculated. RESULTS: The mean difference between pulse oximetry and measured oxygen saturation (bias) was 5.0% and the SD (precision) was 5.3. Twenty-one patients had a PaO(2) greater than 70 mm Hg; 7 of these (33%) were predicted to be hypoxic by pulse oximetry with values less than 93%, for a specificity to detect normoxia of 67%. CONCLUSION: Making treatment decisions based on pulse oximetry data alone in patients with sickle cell disease who are not acutely ill may be inappropriate.     

Two molecular forms of adrenomedullin in congenital heart disease

To investigate the pathophysiological role of two forms of adrenomedullin (AM), a mature AM (AM-m) and a glycine-extended AM (AM-Gly), in congenital heart disease, we measured plasma levels of AM in patients with cyanotic heart disease, high pulmonary blood flow without pulmonary hypertension (PH), high pulmonary blood flow with PH, Fontan procedure, intracardiac repair without complication, and intracardiac repair with PH and control subjects. Plasma AM-m and AM-Gly were increased only for cyanotic heart disease (2. 5 ± 1.3 pmol/L, p < 0.001; 13.1 ± 6.2 pmol/L, p < 0.05) and intracardiac repair with PH (2.3 ± 1.5 pmol/L, p < 0.01; 13.0 ± 7.0 pmol/L, p < 0.05) compared with control (1.0 ± 1.4 and 8.6 ± 1.3 pmol/L, respectively). They were similarly correlated with mean systemic arterial pressure (r = –0.40 and –0.37 respectively; p < 0.001), mixed venous oxygen saturation (r = –0.60 and –0.50; p < 0.0001), systemic arterial oxygen saturation (SA_sat) (r = –0.56 and –0.46; p < 0.0001), and pulmonary arterial resistance (Rp) (r = 0.41 and 0.38; p < 0.005). Multiple regression analysis revealed that SA_sat and Rp were independently correlated with AM. Interestingly, the venous AM-m level was significantly higher than the arterial AM-m, suggesting that the mature form is extracted in pulmonary circulation, whereas there were no venoarterial differences in AM-Gly. These results suggest that plasma AM-m and AM-Gly are similarly regulated and the main clearance site of AM-m is the lung in patients with congenital heart disease.     

功能性单心室的外科治疗及近期疗效

目的 总结功能性单心室的外科治疗经验.方法 回顾性分析我科2003年12月至2010年7月59例功能性单心室患儿,对其手术时机,手术方式及手术效果进行分析,并用Logistic回归分析Glenn手术的高危因素.结果 死亡8例(病死率13.56%),其中4例为Glenn术后死于低心排和多器官功能衰竭,2例为Banding术后死于低心排,1例为TCPC术后死于多器官功能衰竭,1例为B-T分流术后死于低心排.Glenn术后的主要并发症为上腔静脉梗阻综合症和低心排,Fontan术后的主要并发症是房性心律失常和胸腔积液.Logistic回归分析得出房室瓣反流是Glenn术后患儿死亡的高危因素.结论 功能性单心室心内畸形复杂,需根据肺血流的情况及早进行姑息手术,选择合适的术式.改良Fontan是进行生理矫正的理想术式,保留肺动脉前向血流的Glenn手术是保证患儿顺利进行Fontan术的有效方法,但需根据肺动脉狭窄的程度进行处理,避免上腔静脉综合症的发生.

Abstract：

Objective To retrospectively analyze the outcome of surgical treatment of patients with functional single ventricle. Methods Betveen December 2003 and July 2010, 59 patients with functional single ventricle underwent corrective surgeries, and were followed up at this center. Their median age was 3. 0 months old at pulmonary artery band surgery (PAB), 13. 5 months at bidirectional Glenn procedure (BDG), and 11 years old at Fontan operation. The variables of the anatomical lesions with single ventricle physiology, combined abnormalities, age at surgery, and type of the surgical procedure were retrospectively analyzed. Logistic regression analysis was also performed to determine the risk factors associated with Glenn. Results Duration of mechanical ventilation was 30. 4 ± 19. 7 hours. Length of stay in ICU was 4. 3 ± 1.6 days. Length of hospital stay was 34. 8 ± 15. 9 d.SpC2 increased from 75 ± 6. 97% to 88 ± 6. 28% after operation. Exercise tolerance was also improved remarkably. Eight deaths were noted after surgery (13. 56%). The leading complications after Glenn surgery were superior vena cava syndrome and low cardiac output syndrome. Complications after Fontan surgery were atrial tachycardia and pleural effusions. Logistic regression analysis suggested atrioventricular valve regurgitation was an important risk factor for the death of the patients had Glenn surgery. Conclusions The clinical outcome of surgical treatment of patients with functional single ventricle is satisfied. The surgical strategy should be made according to anatomic abnormality of the functional single ventricle and pulmonary circulation. Modified Fontan operations can become an alternative therapy for patients who are not suitable for double ventricle correction. Glenn with antegrade pulmonary blood flow may be a temporary palliation prior to Fontan surgery, but the pulmonary blood flow should be controlled to avoid the occurrence of superior vena cava syndrome.     

Correlation of abdominal site near-infrared spectroscopy with gastric tonometry in infants following surgery for congenital heart disease.

OBJECTIVE: Splanchnic oximetry, as measured by near-infrared spectroscopy (NIRS), correlates with gastric tonometry as a means of assessing regional (splanchnic) oxygenation and perfusion. DESIGN: Prospective, data-gathering study. SETTING: Pediatric cardiac intensive care unit in a tertiary care children's hospital. SUBJECTS: Neonates and infants with congenital heart disease who underwent catheter intervention or surgical repair requiring cardiopulmonary bypass. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Twenty neonates and infants were studied within 48 hrs of surgery. We measured somatic saturation (rSO2) via NIRS sensors placed over the anterior abdomen (splanchnic bed) and dorsal lateral flank (renal bed). Somatic rSO2 readings were paired with simultaneous points of intramucosal gastric pH (pHi), measured by tonometry. The rSO2 readings were paired with serum lactate and measurements of systemic mixed venous saturation (SVO2). There was strong correlation between the abdominal rSO2 and pHi (r = .79; p < .0001) as well as between abdominal rSO2 and SVO2 (r = .89; p < .0001). There was also significant negative correlation between the abdominal rSO2 and serum lactate (r = .77; p < .0001). Correlations between the dorsal lateral (renal) rSO2 measurements and serum lactate and SVO2 were also significant but not as strong. CONCLUSIONS: Abdominal site rSO2, measured in infants with either single or biventricular physiology, exhibits a strong correlation with gastric pHi as well as with serum lactate and SVO2. The results indicate that rSO2 measurements over the anterior abdominal wall correlate more strongly than flank rSO2 with regard to systemic indices of oxygenation and perfusion. This study suggests that the NIRS monitor is a valid modality to obtain an easy, immediate, and noninvasive measurement of splanchnic rSO2 in infants following cardiac surgery for congenital heart disease.     

Near-Infrared Spectroscopic Monitoring During Cardiopulmonary Exercise Testing Detects Anaerobic Threshold

Cardiopulmonary exercise testing (CPET) provides assessment of the integrative responses involving the pulmonary, cardiovascular, and skeletal muscle systems. Application of exercise testing remains limited to children who are able to understand and cooperate with the exercise protocol. Near-infrared spectroscopy (NIRS) provides a noninvasive, continuous method to monitor regional tissue oxygenation (rSO2). Our specific aim was to predict anaerobic threshold (AT) during CPET noninvasively using two-site NIRS monitoring. Achievement of a practical noninvasive technology for estimating AT will increase the compatibility of CPET. Patients without structural or acquired heart disease were eligible for inclusion if they were ordered to undergo CPET by a cardiologist. Data from 51 subjects was analyzed. The ventilatory anaerobic threshold (VAT) was computed on [Formula: see text] and respiratory quotient post hoc using the standard V-slope method. The inflection points of the regional rSO2 time-series were identified as the noninvasive regional NIRS AT for each of the two monitored regions (cerebral and kidney). AT calculation made using an average of kidney and brain NIRS matched the calculation made by VAT for the same patient. Two-site NIRS monitoring of visceral organs is a predictor of AT.     

Modified Fontan Operation in Patients with Anomalies of Systemic and Pulmonary Venous Connection

The presence of anomalies of the systemic and pulmonary venous connection associated with single ventricle anomalies has been considered a contraindication for the Fontan operation (FO). The aim of this study is to outline the technical considerations associated with the presence of anomalies of systemic and/or pulmonary venous connections and to identify the risk factors for mortality in this group of patients undergoing the modified FO. Between 1989 and 2004, 63 patients (median age, 3.2 years) with anomalous systemic or pulmonary venous connection underwent a Fontan procedure at our institution. Nine patients had a combination of anomalous systemic and pulmonary venous connection, 49 patients had anomalous drainage only from the systemic circulation, and 5 patients had isolated anomalies of pulmonary venous return. Visceral heterotaxy syndrome was diagnosed in 25 patients. Previous palliative operations had been performed in 51 patients (81%). There was 1 early death, and 2 patients required take down of Fontan procedures. Two patients required reoperation for revision of the atrial baffle. At a mean follow-up of 4.6 ± 3.4 years, there have been 5 late deaths (8%) and 45 patients (71%) have undergone Fontan completion. Actuarial survival was 92% at 1 year and 91% at 5 and 10 years-not significantly different from the overall survival of the Fontan patients. We conclude that the modified FO can be successfully performed in patients with anomalous systemic or pulmonary venous connections, including those with visceral heterotaxy syndrome, with morbidity and mortality rates that do not differ significantly from those achieved in all patients with normal connections.     

Successful management of living donor liver transplantation for biliary atresia with single ventricle physiology—from peri‐transplant through total cavopulmonary connection: A case report

Children with single ventricle physiology have complete mixing of the pulmonary and systemic circulations, requiring staged procedures to achieve a separation of these circulations, or Fontan circulation. The single ventricle physiology significantly increases the risk of mortality in children undergoing non‐cardiac surgery. As liver transplantation for patients with single ventricle physiology is particularly challenging, only a few reports have been published. We herein report a case of successful LDLTx for an 8‐month‐old pediatric patient with biliary atresia, heterotaxy, and complex heart disease of single ventricle physiology. The cardiac anomalies included total anomalous pulmonary venous return type IIb, intermediate atrioventricular septal defect, tricuspid regurgitation grade III, coarctation of aorta, interrupted inferior vena cava, bilateral superior vena cava, and polysplenia syndrome. Following LDLTx, the patient sequentially underwent total cavopulmonary shunt + Damus‐Kaye‐Stansel at 3 years of age and extracardiac total cavopulmonary connection (EC‐TCPC) completion at 5 years of age; 7 years have now passed since LDLTx (2 years post–EC‐TCPC). We describe the details of the management of LTx in the presence of cardiac anomalies and report the long‐term cardiac and liver function, from peri‐LDLTx through EC‐TCPC completion.     

Surgical therapy for the univentricular heart

The natural history of the univentricular physiology is determined primarily by the presence (severity) or absence of obstruction to pulmonary blood flow and secondarily by the single ventricular cardiomyopathy that develops in response to chronic volume overload. Important obstruction to pulmonary blood flow will affect survival because of severe hypoxia and may necesitate surgical treatment (systemic to pulmonary artery shunt or cavopulmonary shunt depending on the age of the patient and a host of other factors). In the absence of significant obstruction to pulmonary blood flow, the symptomatology is one of congestive heart failure with later development of irreversible pulmonary vascular disease. In this situation, a pulmonary artery band is indicated to limit pulmonary blood flow and reduce pulmonary artery pressures to acceptable levels. Even in the presence of significant limitation of pulmonary blood flow, the single ventricle is a volume-loaded ventricle as it receives both pulmonary and systemic venous retum. Chronic volume overload and persistent hypoxia is detrimental to ventricular function and gradually lead to the development of atrioventricular valve incompetence. Complete separation of oxygenated and deoxygenated blood may be obtained by ventricular septation in suitable cases (beyond the scope of this presentation) or by systemic venous diversion to the pulmonary (the Fontan circulation) arteries thus achieving complete oxygenation simultaneous with abolition of any recirculation.     

Single-ventricle physiology: perioperative implications

Neonates with functional single ventricles have pulmonary and systemic circulations that are supplied in parallel, creating significant cyanosis and ventricular volume overload. The goal of palliative surgery, excluding transplantation, is to convert single-ventricle circulation from a parallel to a series arrangement. This will ultimately require a complete cavopulmonary anastomosis (Fontan-type procedure) in which vena caval blood is rerouted directly into the pulmonary circulation. Various factors require that this palliation occur in stages. Stage I surgery, which is often a Norwood procedure, is done in the neonatal period and stabilizes, but does not resolve, parallel circulation. The tenuous balance between pulmonary and systemic perfusion during this stage makes noncardiac surgery hazardous, and it should be restricted to urgent or emergent indications. Stage II surgery, or partial cavopulmonary anastomosis, relieves both parallel circulation and volume overload, but not cyanosis. Relatively stable hemodynamics during this stage create favorable conditions for elective surgery. Patients who have undergone stage III surgery, the Fontan-type repair, vary in age from toddlers to adults, and in physical status from well-compensated to significantly debilitated. Fontan patients require thorough preoperative assessment when elective surgery is contemplated. Optimal communication between surgeons, anesthesiologists, and cardiologists is essential when caring for the patient with single-ventricle physiology.     

Low Renal Oximetry Correlates With Acute Kidney Injury After Infant Cardiac Surgery

Acute kidney injury (AKI) is a frequent complication after cardiopulmonary bypass surgery during infancy. Standard methods for evaluating renal function are not particularly sensitive nor are proximate indicators of renal dysfunction that allow intervention in real time. Near-infrared spectroscopy (NIRS) is a newer noninvasive technology that continuously evaluates regional oximetry and may correlate with renal injury and adverse outcomes after cardiac surgery in infants. This prospective observational study enrolled 40 infants (age, <12 months) undergoing biventricular repair. Continuous renal oximetry data were collected for the first 48 postoperative hours and correlated with postoperative course, standard laboratory data, and the occurrence of acute renal injury. Subjects with low renal oximetry (below 50% for >2 h) had significantly higher postoperative peak creatinine levels by 48 h (0.8 ± 0.4 vs. 0.52 ± 0.2; p = 0.003) and a higher incidence of AKI (50 vs. 3.1%; p = 0.003) than those with normal renal oximetry. These subjects also required more ventilator days and greater vasoactive support, and they had elevated lactate levels. Prolonged low renal near-infrared oximetry appears to correlate with renal dysfunction, decreased systemic oxygen delivery, and the overall postoperative course in infants with congenital heart disease undergoing biventricular repair.     

Lung Perfusion Patterns After Bidirectional Cavopulmonary Anastomosis (Hemi-Fontan Procedure)

Perfusion lung scans were performed immediately prior to Fontan procedure in 45 patients with a functional single ventricle who underwent the hemi-Fontan procedure as an intermediate stage between the initial palliative shunt procedure and the final complete Fontan anastomosis. Symmetric pulmonary blood flow (PBF) distribution was found in 27% of patients, whereas moderately to severely abnormal PBF distribution was found in 35% of patients. The achieved systemic aortic saturation following the hemi-Fontan procedure was not affected by these abnormalities.     

Present status of surgery in congenital heart disease

A brief historical review of surgery for congenital heart disease is presented. Palliative procedures designed to improve a given physiologic abnormality, such as systemic artery (or venous) to pulmonary artery shunts of various types to increase the pulmonary blood flow, banding of the pulmonary artery to decrease the pulmonary blood flow and surgical or balloon atrial septostomy to augment intracardiac mixing have been performed with success. Most of the congenital heart defects can be corrected by open heart surgical techniques; those requiring prior pallition and those that can be operated without prior palliative surgery are listed. The mortality rates for several common congenital heart defects are tabulated. Recent surgical advances include early total surgical correction for tetralogy of Fallot, Mustard and Jatene operations for transposition of the great arteries, Fontan operation and its newer modifications for tricuspid atresia, intraventricular septation or modified Fontan for single ventricle, new operations for hypoplastic left heart syndrome and newer prosthetic valves, particularly left ventricular apex to descending aorta conduit. Prostaglandin E₁ for ductal dilation in patients with severe righ ventricular outflow tract obstruction, balloon and knife enlargement of atrial defects to enhance interatrial mixing and catheter closure techniques for nonsurgical repair of atrial septal defect and patent ductsus arteriosus are also reviewed briefly.     

Ventricle works as a converting organ of atrial blood flow: Physiological significance of mean ventricular pressure

The roles and characteristics of the ventricle were examined using mean ventricular pressure (MVP) in ventricular-vascular assocation. One hundred and two patients with congenital heart diseases who had undergone cardiac catheterization were studied. They were divided into five groups: Group 1, atrial septal defect without pulmonary hypertension (PH); Group 2, ventricular septal defect (VSD) without PH; Group 3, VSD with PH; Group 4, pulmonary valvular stenosis; and Group 5 as a control group. Then, we examined the relationships between mean pulmonary artery pressure (MPAP) and mean right ventricular pressure (MRVP), and also between mean systemic arterial pressure (MSAP) and mean left ventricular pressure (MLVP) among the five groups. Furthermore, we defined new indicators to express the ease of blood flow through each ventricle. They were referred to as a conductance of the right ventricle (CD_R) and a conductance of the left ventricle (CD_L), respectively. Then they were compared among the five groups. The values of MPAP/MRVP and MSAP/MLVP were kept constant to be about 1.3 and 1.7, respectively. Furthermore, CD_R was different betweeen each group according to the property of the pulmonary vascular bed, whereas CD_L took almost the same value among the five groups. The ventricle works as a converter of atrial blood flow so that it can achieve efficient blood transport.     

Celiac artery flow pattern in infants with single right ventricle following the Norwood procedure with a modified Blalock-Taussig or right ventricle to pulmonary artery shunt

A potential advantage of the right ventricle to pulmonary artery versus modified Blalock?CTaussig shunt in patients undergoing the Norwood procedure is limitation of diastolic runoff from the systemic to pulmonary circulation. We evaluated mesenteric flow patterns and gastrointestinal outcomes following the Norwood procedure associated with either shunt type. Patients randomized to a right ventricle to pulmonary artery versus modified Blalock?CTaussig shunt in the Pediatric Heart Network Single Ventricle Reconstruction Trial at centers participating in this ancillary study were eligible for inclusion; those with active necrotizing enterocolitis, sepsis, or end-organ dysfunction were excluded. Celiac artery flow characteristics and gastrointestinal outcomes were collected at discharge. Forty-four patients (five centers) were included. Median age at surgery was 5?days [interquartile range (IQR)?=?4?C8?days]. Median celiac artery resistive index (an indicator of resistance to perfusion) was higher in the modified Blalock?CTaussig shunt group (n?=?19) versus the right ventricle to pulmonary artery shunt group (n?=?25) [1.00 (IQR?=?0.84?C1.14) vs. 0.82 (IQR?=?0.74?C1.00), p?=?0.02]. There was no difference in interstage weight gain, necrotizing enterocolitis, or feeding intolerance episodes between the groups. The celiac artery resistive index was higher in patients with the modified Blalock?CTaussig shunt versus the right ventricle to pulmonary artery shunt but was not associated with measured gastrointestinal outcomes.     

Usefulness of a new Doppler index for assessing both ventricular functions and pulmonary circulation in newborn piglet with hypoxic pulmonary hypertension

Persistent pulmonary hypertension of the newborn is a clinical syndrome associated with a variety of cardiopulmonary diseases. Serial evaluation of pulmonary circulation and cardiac function is important, but available imaging techniques have been limited. A new Doppler index combining systolic and diastolic time intervals (the Tei index, which is a simple and noninvasive measurement) has been reported to be useful for the assessment of global cardiac function in adults and children. The purpose of this study was to test the effectiveness of the Tei index in prospectively assessing ventricular function and pulmonary circulation in a newborn piglet model with hypoxic pulmonary hypertension. One-day-old piglets (1.1-1.6 kg) were intubated and prepared for the experiments under room air and hypoxia. A complete two-dimensional Doppler echocardiographic examination was performed. Common hemodynamic variables were measured continuously throughout the study. The right ventricle (RV) Tei index under hypoxia (fraction of inspired oxygen = 0.10) was significantly higher than the value under air ventilation (medians, 0.38 versus 0.56; p < 0.05). Moreover, there was a significant correlation between RV Tei index and mean pulmonary artery pressure and positive linear correlation between individual changes in RV Tei index and changes in mPAP (r2 = 0.799, p < 0.05). We conclude that the Tei index is useful for assessing the function of the RV and the left ventricle and pulmonary circulation in a newborn piglet model with hypoxic pulmonary hypertension. These results suggest that the Tei index will become an objective method of assessing patients with persistent pulmonary hypertension of the newborn.     

Hypoplastisches Linksherzsyndrom

Since the middle of the 1980s it has been possible to palliate patients suffering from hypoplastic left heart syndrome. In the first step the hypoplastic aortic arch is reconstructed and the lung is perfused by a shunt. In the further surgical step a separation of systemic and pulmonary circulation is performed. The pulmonary perfusion remains passive and the work load of the right ventricle will be optimized. This operative procedure has now become a standard procedure and helps these patients to survive with a good quality of life.