Reliability of Fetal Echocardiography in Predicting Postnatal Critical Hypoxia in Patients with Transposition of Great Arteries and Intact Ventricular Septum.

Critical hypoxemia soon after birth is the most critical preoperative determinant of neurological outcomes and survival in newborns with Dextro Transposition of the Great Arteries and Intact Ventricular Septum (D-TGAIVS). Our study aimed to define fetal echocardiographic aspects that can better predict neonates with D-TGAIVS at risk for restricted interatrial communication after birth. 31 fetuses with a prenatal diagnosis of D-TGAIVS were included in our study. We divided patients with D-TGAIVS according to the timing of balloon atrial septostomy: Urgent, Not-Urgent and no BAS. We identified five fetal echocardiographic aspects of the interatrial septum (redundant, aneurysmal, flat, fixed, hypermobile). No significant differences in these fetal echocardiographic features were found between the three different groups of D-TGAIVS according to the timing of balloon atrial septostmy. However, only two patients showed flat appearance of interatrial communication: both needed Urgent balloon atrial septostomy. The prevalence of hypermobile septum primum was significantly lower in the control group compared to patients with D-TGAIVS. Fetal echocardiographic aspects cannot predict patients with D-TGAIVS who will not need Urgent balloon atrial septostomy. Therefore, we recommended a delivery in a tertiary center, equipped for Urgent balloon atrial septostomy, for all patients with D-TGAIVS regardless of fetal echocardiographic features.

Pediatric heart failure.

Heart failure is a clinical syndrome which presents similarities and differences between children and adults; in pediatric age the spectrum of causes of heart failure is wide and congenital heart defects are the most common etiology. Volume and pressure overload on a ''normal myocardium'' is the classical physiological pattern while myocardial contractile dysfunction of different etiology is much less observed in the pediatric population. However there are some peculiarities in clinical presentation of heart failure in infants and small children. The medical therapy cornerstones still remain loop diuretics, angiotensin-converting enzyme inhibitors, beta-blockers and digitalis. There are also some reported experiences with new inotropics drugs in acute heart failure. In pediatric cardiology there are few prospective studies on pharmacology of heart failure and the data are often extrapolated from adult large trials. Non pharmacological treatment with autonomic implantable cardioverter defibrillators and resynchronization therapy as well as the surgically implant of ventricular assist devices are increasingly employed in children. Cardiac transplantation is currently the treatment option with good outcome and long-term survival in pediatric patients with end-stage or refractory heart failure.

Minimally invasive or interventional repair of atrial septal defects in children: experience in 171 cases and comparison with conventional strategies.

OBJECTIVES: The goal of this study was to evaluate percutaneous interventional and minimally invasive surgical closure of secundum atrial septal defect (ASD) in children. BACKGROUND: Concern has surrounded abandoning conventional midline sternotomy in favor of the less invasive approaches pursuing a better cosmetic result and a more rational resource utilization. METHODS: A retrospective analysis was performed on the patients treated from June 1996 to December 1998. RESULTS: One hundred seventy-one children (median age 5.8 years, median weight 22.1 kg) underwent 52 device implants, 72 minimally invasive surgical operations and 50 conventional sternotomy operations. There were no deaths and no residual left to right shunt in any of the groups. The overall complication rate causing delayed discharge was 12.6% for minimally invasive surgery, 12.0% for midline sternotomy and 3.8% for transcatheter device closure (p < 0.01). The mean hospital stay was 2.8 +/- 1.0 days, 6.5 +/- 2.1 days and 2.1 +/- 0.5 days (p < 0.01); the skin-to-skin time was 196 +/- 43 min, 163 +/- 46 min and 118 +/- 58 min, respectively (p < 0.001). Extracorporeal circulation time was 49.9 +/- 10.1 min in the minithoracotomy group versus 37.2 +/- 13.8 min in the sternotomy group (p < 0.01) but without differences in aortic cross-clamping time. Sternotomy was the most expensive procedure (15,000 EUR +/- 1,050 EUR vs. 12,250 EUR +/- 472 EUR for minithoracotomy and 13,000 EUR +/- 300 EUR for percutaneous devices). CONCLUSIONS: While equally effective compared with sternotomy, the cosmetic and financial appeal of the percutaneous and minimally invasive approaches must be weighed against their greater exposure to technical pitfalls. Adequate training is needed if a strategy of surgical or percutaneous minimally invasive closure of ASD in children is planned in place of conventional surgery.

Effects of angiotensin II on myocardial contractility during short-term pressor responses to angiotensin II.

BACKGROUND: Cardiac angiotensin AT1 receptors have been found in several animal species. In-vitro studies performed on cardiac preparations have shown that angiotensin II (ANG II) exerts a positive inotropic effect; however, in-vivo results have allowed no definitive conclusion to be drawn. The reasons behind these controversial results remain unknown, and could originate both from different experimental conditions and from the techniques used to assess myocardial contractility. OBJECTIVE: To investigate, by means of echocardiographic measurements, whether ANG II, administered to intact and to sinoaortic denervated isoflurane-anesthetized rabbits, was able to directly increase myocardial contractility. METHODS: The effect of ANG II on cardiac contractility was assessed with the use of simultaneous pressure measurements and Doppler-echocardiographic recordings. Specifically, we used both the relationship between the left ventricular end-systolic wall stress and the velocity of heart-rate-corrected circumferential fiber shortening (VCFC) and the maximum rate of rise of the ventricular pressure as indices of changes in myocardial contractility. Cardiac contractility was evaluated both in intact and in chronically sinoaortic denervated isoflurane-anesthetized rabbits under basal conditions and after ANG II infusion (50 ng/kg per min). RESULTS: After ANG II infusion, increases in mean arterial blood pressure, left ventricular end-diastolic diameter and pressure were observed both in intact and in chronically sinoaortic denervated rabbits. The left ventricular end-systolic wall stress (a function of the mean arterial pressure and chamber size) and the maximum rate of rise of the ventricular pressure rose markedly in rabbits of both groups, whereas the VCFC decreased significantly. However, when compared the VCFC under ANG II infusion with that calculated at the same level of left ventricular afterload under basal conditions, we observed that ANG II infusion induced no significant change in VCFC either in intact of in chronically sinoaortic denervated rabbits. CONCLUSION: Our results indicate that administration of ANG II to isoflurane-anesthetized rabbits induces a marked rise in ventricular pre- and after-loads and exerts no significant effect on the cardiac contractility. In light of this, it is reasonable to assume that the short-term increase in arterial blood pressure can be ascribed mainly to the increase in peripheral arterial resistance.

Comparison of three different atrial septal defect occlusion devices.

Three different devices were used to close secundum-type atrial septal defects in 28 patients. The "Amplatzer" is associated with an easier and shorter procedure than are the "Sideris Buttoned Device" and the Microvena "Angel Wings" devices.

Patent ductus arteriosus occlusion using detachable coils.

Occlusion of patent ductus arteriosus was performed using detachable coils in 193 cases, with 181 successful implants and a low embolization rate. This technique is safe and effective for occlusion of ductuses of various sizes, and is low cost.

Associated cardiac anomalies in isolated and syndromic patients with tetralogy of Fallot.

To detect in children with tetralogy of Fallot (ToF) the prevalence of associated cardiac anomalies in syndromic and isolated cases, the additional cardiac defects of 150 consecutive patients with ToF (102 isolated and 48 syndromic cases) were evaluated by review of echocardiographic, angiocardiographic, and surgical reports. Syndromic patients were classified into groups with branchial arch defects, Down syndrome, and other genetic conditions. ToF is significantly associated with additional cardiac malformations in patients with branchial arch (11 of 21, p <0.01) and Down (10 of 20, p <0.0001) syndromes. The subarterial ventricular septal defect with deficiency of the infundibular septum (4 of 21, p <0.01) and the right aortic arch (6 of 21, p <0.05) were prevalent in patients with branchial arch syndromes, whereas atrioventricular canal (10 of 20, p <0.0001) was associated with ToF in patients with Down syndrome. Peculiar anatomic cardiac patterns are present in children with ToF and may alert the cardiologist to look at additional cardiac anomalies. Moreover, the presence of some associated cardiac anomalies may suggest careful clinical evaluation for genetic syndromes.

Echocardiographically guided repair of tetralogy of Fallot.

Although 2-dimensional, Doppler, color flow echocardiography is accepted as a safe diagnostic method to guide the surgical treatment of certain heart defects, cardiac catheterization remains mandatory for patients with tetralogy of Fallot. Based on the excellent diagnostic correlation between echocardiography and angiocardiography, a policy of echo-guided primary repair of uncomplicated, selected cases of tetralogy of Fallot was introduced at Ospedale Bambino Gesù. In the last 5 years, of 139 patients who had surgery for tetralogy of Fallot, 105 underwent primary repair. In 56 patients (53.3%), surgery was guided only by echocardiography (group I). In the remaining 49 patients (46.7%) (group II), unclear imaging of cardiovascular anatomy (n = 23), or echo-suspected associated malformations (n = 26) prompted cardiac catheterization. The 2 groups did not differ in age and weight at surgery. Intraoperative examination did not show diagnostic errors in patients of group I; cardiac catheterization and surgery confirmed the suspected associated anomalies in 16 of 26 patients of group II (38.4% false-positive). Echocardiography showed an overall sensitivity of 100% and specificity of 85% for detection of associated malformations. In conclusion, echocardiography proved to be adequate for selection of patients with uncomplicated forms of tetralogy of Fallot for primary repair.

Pathology of atrioventricular valve dysplasia.

The congenital heart disease series of the Pathological Museum at La Sapienza University of Rome was revised in order to detect specimens featuring atrioventricular valve dysplasia (AVVD) in fetuses and infants. Selected for study were 67 specimens from a collection of 667 hearts: there were 36 cases of isolated tricuspid valve dysplasia (TVD), 11 cases of isolated mitral valve dysplasia (MVD), and 20 cases of combined atrioventricular valve dysplasia. All the valves were graded according to Becker's criteria, which were morphometrically validated. There is an increasing degree of dysplasia in terms of differentiation and detachment of the valve from the ventricular wall. The concept of AVVD is supported by a substantial morphologic and morphometric analogy between TVD and MVD, in spite of some peculiarities of each grade and of side-specific anomalies ("mitral arcade" on the left side and grade III dysplasia on the right one), probably attributable to differences in the embryonic development of the two valves. AVVD is sometimes associated with dysplasia of the semilunar valves, in the setting of a polyvalvular disease of possible genetic origin. More often it is combined with other defects that cause ventricular overload. In such cases, AVVD usually occurs within the overloaded cardiac section, as if it were a result of mechanical stress.

Midterm follow-up of the Amplatzer device in left ventricle-to-aorta conduits.

The midterm follow-up of 2 patients with left ventricle-to-aorta conduit who underwent percutaneous closure with the Amplatzer device is described. Complete occlusion was achieved immediately in 1 patient. In the other patient, a trivial residual shunt was still present after 12 months, but disappeared after 18 months. Occlusion of dysfunctional left ventricle-to-aorta conduits by the Amplatzer device is feasible, provided that enough time is allowed for complete occlusion.

Origin of both coronary arteries from the pulmonary artery and aortic coarctation.

Single trunk anomalous origin of both coronary arteries from the pulmonary artery is a rare congenital cardiac anomaly. We report on 2 cases of its association with aortic coarctation, the diagnosis of which in living patients is very difficult. We think that the possibility of this anatomic arrangement should always be considered in patients with isolated aortic coarctation whose clinical condition seems impaired rather than improved after an apparently successful coarctectomy.

Partial atrioventricular canal with congestive heart failure in the first year of life: surgical options.

BACKGROUND: An important subgroup of patients with partial atrioventricular canal require an operation in the first year of life because of refractory congestive heart failure. METHODS: From June 1982 to April 1995, of 128 patients with partial atrioventricular canal, 35 patients (27%) underwent surgical treatment at less than 1 year of life. Associated cardiac anomalies were present in 22 patients. Only 7 patients (20%) had Down's syndrome. Five patients with left ventricular hypoplasia underwent aortic coarctectomy (3 patients) or Norwood operation (2 patients). The other 30 patients underwent anatomic repair in 24 cases and aortic coarctectomy in 6. The surgical results of patients submitted for anatomic repair were retrospectively correlated with the echocardiographic mitral valve diameter. RESULTS: There were 7 deaths (29%) after anatomic repair, 2 (22%) after aortic coarctectomy, and 2 (100%) after Norwood operation. Infants with a mitral valve diameter less than 2.5 x 10-2 m/m2 died at repair. In a mean follow-up of 73.5 months there were five secondary mitral valve plasties and three repairs after aortic coarctectomy. CONCLUSIONS: Among patients with partial atrioventricular canal, there is an important subgroup with clinical signs of heart failure in the first year of life. Left-sided obstructive lesions and complex mitral valve anomalies seem to play a fundamental role in the clinical evolution and prognosis of these patients. The echocardiographic mitral valve diameter may be useful for determining the correct surgical indication.

ET(A)/ET(B) receptor antagonist bosentan inhibits neointimal development in collared carotid arteries of rabbits.

The contribution of endothelin to the genesis of neointimal development in collared rabbit carotid arteries, a widely accepted model of atherosclerosis, was investigated. Three sets of rabbits were studied. In the first group, a non-occlusive, biologically inert silastic collar was positioned around the right carotid artery of the rabbit. In another group, the application of the collar was accompanied by endothelial denudation via a Fogarty arterial balloon catheter, while the third group of animals underwent only endothelial denudation. After two weeks, intimal hyperplasia of a similar degree was observed in all groups. The administration of the nonselective ET(A)/ET(B) receptor antagonist Bosentan, significantly reduced both the neointimal area and the intima/media area ratio in all groups. However, the beneficial effects of Bosentan were less pronounced in balloon injured vessels than in collared ones. The results of the present study indicate that i) endothelin has a key role in the development of intimal hyperplasia following arterial collaring, ii) the contribution of endothelin to intimal hyperplasia is greater in collared arteries that in balloon injured ones, and iii) the nonselective ET(A)/ET(B) receptor antagonists are potential tools for the prevention of intimal hyperplasia.

Patient selection for repair of complete atrioventricular canal guided by echocardiography.

OBJECTIVE: Two-dimensional, Doppler and color-flow echocardiography is accepted as a safe diagnostic tool to guide the surgical treatment of certain congenital heart defects. Its role for surgical indication in patients with complete atrioventricular canal (cAVC) is described in this paper. METHODS: Between July 1989 and January 1995, 80 patients with cAVC underwent primary repair in our Institution. In 73 surgery was guided only by echocardiography (Group I), while in the remaining 7 patients (Group II) cardiac catheterization was performed because of unclear diagnosis and/or suspected associated malformations. RESULTS: Echocardiography showed an overall sensitivity of 100% and specificity of 93% in detecting associated malformations. DISCUSSION: Based on these data and on the knowledge of the natural history of pulmonary vascular changes in patients with cAVC we think that echocardiography might be adequate for selection of infants with uncomplicated forms of cAVC for primary repair.

Left ventricular outflow tract obstruction in atrioventricular septal defects: a pathologic and morphometric evaluation.

Subaortic stenosis has been described with increasing frequency as an ominous feature of atrioventricular septal defect (AVSD), especially following surgical correction of the anomaly in non-Down's syndrome patients. In order to study the surgical anatomy of the left ventricular outflow tract in this malformation, 48 hearts featuring AVSD were examined. Obstructive lesions were classified into unequivocal forms (class A, 13.5%) and potential ones (class B, 10.8%). In the remaining hearts (class C, 75.7%) no obstruction was noted. In class A, subaortic stenosis was due to exaggeration of the anticipated anomalous arrangement of atrioventricular valve tensor apparatus, to the persistence of a subaortic muscular infundibulum, and to a discrete fibrous diaphragm. A potential for subaortic stenosis is provided by the unwedged position of the aortic valve. The left ventricular outflow tract is transformed into a long, forward-displaced fibromuscular channel. Morphometric analysis showed in AVSD (with both common annulus and separate orifices) a significantly (p less than 0.01) lower inflow/outflow tract ratio, and a significantly (p less than 0.01) lower right ventricular/left ventricular outflow length ratio than normal hearts. These results suggest that AVSD is characterized not only, as commonly stated, by inflow tract shortening, but by outflow tract lengthening as well. On these anatomical grounds, nearly all cases of AVSD could harbor the potential for subaortic stenosis; however, this becomes a real hazard (class B) only when associated with forward displacement of the left anterior papillary muscle, or direct insertion on the ventricular septum of the anterior bridging leaflet, and it may be converted to an actual obstruction by the effects of surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Pulsatile flow and atherogenesis: results from in vivo studies.

Compliance mismatch between prosthetic vascular replacement (possibly stented) and native artery is considered to be an important factor in implant failure due, e.g., to vascular remodeling, tissutal growth or intimal hyperplasia (IH). From an in vivo study involving altered vascular mechanics (and, consequently, compliance mismatch), carried out using the Moncada model of atherosclerosis development and smooth muscle cell (SMC) proliferation, the hemodynamic assessment was followed by means of real-time multigated ultrasound profilometry, of collared carotid artery using two different models: non-constrictive and constrictive plastic collars, wrapped around the vessel. The experiments provided the real-time measurement of velocity profiles in vivo and the subsequent estimation of wall shear stresses, locally responsible for the altered hemodynamics. Endothelium modifications were correlated with local hemodynamic alterations by using statistical regression analysis of the development of intimal hyperplasia and the mechanical stimulus applied to the endothelium by means of the two different manipulation models. Different correlations were found between wall shear rate and IH in the two models, showing the importance of the vascular pulsatility in determining SMC proliferation. This result could be useful in minimizing the negative consequences of clinical interventions such as graft and/or stent implantation.

Extracorporeal circulation in ewe's foetus: towards a reliable foetal cardiac surgery protocol. A comparison of two cases.

UNLABELLED: Foetal cardiac surgery is the ultimate goal in the treatment of congenital cardiac malformations. The aim of our research is to elucidate some of the features of the necessarily invasive experimental protocol to be used in an animal model of foetal cardiac surgery. In particular, we assessed the foetal placental reactivity to prolonged cardiac bypass in steady-flow conditions. METHODS: Two cases were selected to show the outcome of prolonged (> 30 minutes) extracorporeal circulation (ECC) instituted without oxygenator under steady-flow assistance. Following the instrumentation of the animal (placement of pressure, flow and myocardial fiber length transducers) and the baseline recordings, a 60-minute bypass period was established with an axial turbopump (Hemopump 14 Fr), after systemic heparinisation and artero-venous cannulation. At the end of the circulatory assistance, the cannulae were removed and a 90 minute observation period followed. The cardiac function was assessed by means of indirectly obtained P-V loops. RESULTS: Case A showed a marked reduction in the end-systolic pressure-volume relationship (ESPVR) during ECC, corresponding to a rightward shift of the P-V loop, with a gradual recovery after the assisted circulation. On the contrary, case B was subjected to progressive placental dysfunction, as evidenced by haemogasanalytical data. Consequently, the haemodynamic data also outlined a negative outcome, with high ESPVR values after bypass. CONCLUSIONS: The present study, while confirming the possibility of cardiac intervention in the foetus, underlines the critical role of minimally invasive protocol to limit both foetal stress and placental dysfunction.

Effects of isoflurane versus halothane on myocardial contractility in rabbits: assessment with transthoracic two-dimensional echocardiography.

The effects of isoflurane versus halothane on cardiac contractility were evaluated by two-dimensional (2D) transthoracic echocardiography in rabbits. The relationship between the left ventricular end-systolic wall stress (LVESWS) and the velocity of heart rate corrected circumferential fibre shortening (Vcfc) was used. Arterial blood pressure, heart rate, left ventricular pressure and transthoracic 2D echocardiogrphic data were determined at 1 MAC (minimum alveolar concentration) of halothane or isoflurane, both with 50% nitrous oxide. Drug-induced changes in pre- and afterload were performed in all study animals to assess the left ventricular contractile response over a wide range. LVESWS and Vcfc were calculated on videotape recorded M-mode tracings. Mean heart rate and arterial blood pressure were not significantly different between the two groups. Myocardial contractility under isoflurane/nitrous oxide anaesthesia was significantly higher than under halothane/nitrous oxide anaesthesia at 1 MAC. The results of the present study confirm data obtained from humans and other animal species and suggest that, in rabbits, myocardial contractility is best preserved by inhalation of isoflurane. Isoflurane should therefore be preferred over halothane, especially in cases of prolonged anaesthetic procedures.