Growth Of Left Heart Structures Research Articles

Kiosk 5R-TC-08 - Role of Systemic-pulmonary Collateral Flow on Growth of Left Heart Structures with Left Ventricular Recruitment

Kiosk 5R-TC-08 - Role of Systemic-pulmonary Collateral Flow on Growth of Left Heart Structures with Left Ventricular Recruitment

Erratum to: Critically Underdeveloped Left Heart Morphology Associated with Prematurity and Low Birth Weight: Conditional Staged Rehabilitation Towards Biventricular Repair and Time-Related Growth of Left Heart Structures.

This is a case report of premature low birth weight infant with hypoplasia of left heart structures and a large malaligned VSD who underwent successful staged approach of biventricular repair. We obtained qualitative and quantitative echocardiographic, MRI, and conventional catheterization data to support stepwise strategy towards LV rehabilitation to sustain adequate cardiac output. A thorough and intense follow-up has shown significant growth of left heart structures and favorable clinical status following staged biventricular repair. Our data indicate usefulness of qualitative and quantitative advanced complimentary multi-imaging modalities in predicting the postnatal growth potential of critically underdeveloped left heart structures.

Staged Left Ventricular Recruitment and Biventricular Conversion for Patients With Borderline Left Heart

A borderline left heart may be present in patients with hypoplastic left heart syndrome or an unbalanced atrioventricular canal defect. Traditionally, such patients have been managed either by high-risk biventricular repair in infancy or during the neonatal period, or by definitive single-ventricle palliation. In this article, we present an approach for staged left ventricular recruitment that promotes gradual rehabilitation of left heart structures and allows delay in the commitment to either a single-ventricle pathway or a biventricular pathway. The rationale, techniques, and early results are described.

Feasibility and safety of biventricular repair in neonates with hypoplastic left heart complex.

Hypoplastic left heart syndrome is a spectrum of structural cardiac malformations characterized by variable underdevelopment of the left heart-aorta complex. A minority of patients having a milder degree of left ventricular hypoplasia, described as hypoplastic left heart complex (HLHC), may be selected for biventricular repair. The objective of this study was to assess the outcome of the biventricular approach in HLHC. We evaluated retrospectively 30 neonates diagnosed with HLHC from the "12 de Octubre" University Hospital, following established criteria. We analyzed the echocardiographic data recorded just after birth and at last follow-up after surgery. All patients were operated on in the neonatal period using various surgical techniques. There were no early deaths and only 1 late death after a mean follow-up of 62.9 ± 43.8 months. All patients presented a significant growth of the left ventricular structures, with a Z-score increase of 1.17 ± 1.05 for mitral annulus, 1.72 ± 1.23 for aortic annulus, and 1.33 ± 1.46 for left ventricular end-diastolic diameter. Postoperatively, 18 patients showed a left valvular stenosis, and 17 patients underwent a reoperation and/or an interventional procedure. Freedom from surgery or interventional catheterizations at 1, 3 and 5 years was 53, 49 and 43%, respectively. The 29 current survivors are all in a good functional status. In our experience, we achieved good results from biventricular repair in patients with HLHC, with a significant growth of left heart structures and an excellent clinical status at a medium-term follow-up. Nevertheless, there was a high rate of reoperations and/or interventional catheterizations.

Growth of left heart structures following the hybrid procedure for borderline hypoplastic left heart

The 'hybrid' procedure is an alternative to the Norwood operation in classical hypoplastic left heart syndrome to support the systemic circulation until subsequent palliation. This approach has been extended to infants with the borderline development of left heart structures. We investigated whether or not a hybrid procedure for 'borderline' cases of underdevelopment of the left heart would lead to any improvement in the growth of those structures relative to body size or would impact on eventual repair. Serial echocardiograms were reviewed in cases in whom left heart development was judged borderline for adequacy to support the systemic circulation. z-scores of left heart structures and aortic discriminant scores were plotted sequentially following the hybrid procedure and random-coefficient linear-mixed models were applied to quantify growth rates. Seven infants met the inclusion criteria. At birth, the median (range) of aortic discriminant scores was -2.67 (-3.26 to -1.22), suggesting that a biventricular repair would not be feasible. Following a hybrid procedure, aortic discriminant scores increased with time and three infants were managed with a biventricular repair. The rate of change was significantly higher in infants who achieved a biventricular repair compared with those who did not (P = 0.01). The hybrid procedure allows time for growth of left heart structures in selected infants, and serial echocardiography may assist in identifying those children who may ultimately achieve a biventricular circulation.

Outcome and Growth Potential of Left Heart Structures After Neonatal Intervention for Aortic Valve Stenosis

The purpose of this study was to determine trends of growth of left heart structures after intervention for neonatal aortic valve stenosis. The growth potential of left heart structures in neonatal aortic valve stenosis after relief of obstruction might influence risk for subsequent outcomes. From 1994 to 2004, 53 patients underwent neonatal (< or =30 days old) balloon aortic valve dilation. Factors associated with time-related outcomes (death, reintervention, aortic valve replacement) and longitudinal changes in normalized left heart dimensions were sought. The median age at intervention was 3.5 days (range 1 to 30 days). During a median follow-up of 3.2 years ranging up to 10.9 years, there were 31 reinterventions on the aortic valve in 21 (40%) patients and 7 deaths (13%). The presence of moderate or severe left ventricular (LV) endocardial fibroelastosis was the only independent predictor for time-related mortality (hazard ratio 22.1; p = 0.004), and a smaller initial aortic valve annulus z-score was a significant independent predictor for aortic valve replacement (hazard ratio 0.63 per 1-U change; p = 0.007). Aortic valve annulus, aortic sinus, and LV dimension z-scores significantly increased over time, whereas mitral valve z-scores remained below normal. The structure's initial z-score and concomitant size of other left heart structures were significant independent factors associated with subsequent z-scores. There is potential catch-up growth of the aortic valve and LV over time for neonates after intervention for aortic valve stenosis. However, the continued hypoplasia of the mitral valve warrants further consideration in the long-term management of these patients.

Left Heart Obstructive Lesions and Left Ventricular Growth in the Midtrimester Fetus

Isolated case reports that suggest the potential for development of left heart hypoplasia late in gestation provide the only information about the in utero natural history of left heart obstructive lesions. We reviewed the prenatal and postnatal echocardiograms of 21 fetuses with left heart obstructive lesions, including 15 with serial antenatal study, to elucidate the antenatal natural history of this spectrum of disease and to identify features indicative of postnatal disease severity. Ventricular, atrioventricular valve, and great artery dimensions were measured and growth curves were developed with comparisons to data from 47 normal fetuses. Fetuses were divided into groups according to whether postnatally the left heart was capable (group 1, n = 10) or incapable (group 2, n = 7) of supporting the systemic circulation in the presence of a patent aortic valve. Group 3 (n = 4) included fetuses with aortic atresia. At the initial examination (21.7 +/- 3.4 weeks' gestation), left heart dimensions were normal or reduced, with the most diminutive measurements in group 3. Three fetuses in group 2 and most in group 1 had normal initial left heart dimensions. Subsequent growth of left heart structures either paralleled normal growth or was reduced, the latter resulting in the development or progression of left heart hypoplasia. All left heart dimensions grew more slowly in group 2 and group 3 than in group 1 (P < .05). Other prenatal features observed only in groups 2 and 3 included reversed (n = 10) or bidirectional (n = 1) foramen ovale flow and retrograde distal arch flow (n = 9). Initial midtrimester mitral valve and ascending aorta z scores and the growth rates of all left heart structures correlated strongly with postnatal left ventricular end-diastolic dimension (P = .0007 to .03, r = .57 to .82) and could be additional indicators of postnatal disease severity. One group 1 fetus developed severe aortic stenosis late in gestation. The potential for the in utero development or progression in severity of left heart obstruction and hypoplasia in left heart obstructive lesions necessitates serial prenatal study in affected fetuses carried to term.

Growth of the hypoplastic ascending aorta after radical palliation

Surgical treatment of hypoplasia of the ascending aorta is a difficult problem. An approach using proximal pulmonary artery to distal aorta bypass with distal pulmonary artery banding was employed in 19 patients with an ascending aorta less than 6 mm in diameter but a patent aortic outflow. There were 11 male and 8 female neonates and infants, and weight ranged from 2 to 4.5 kg (median weight, 3.5 kg). Four patients had transposition of the great arteries, 12 had subaortic stenosis, and 5 had interrupted aortic arch. There was one operative death. Cerebral cyanosis developed in 3 of the 4 patients with transposition of the great arteries and necessitated additional operations within the first year postoperatively. Therefore, palliation with a pulmonary artery to descending aorta conduit and banding was abandoned in such patients. All 14 surviving patients with normally related great arteries had successful palliation and growth of left heart structures. Subsequent procedures included a Fontan/Damus procedure in 1 patient, patch aortoplasty and pulmonary arterioplasty in 5 patients, arch reconstruction with aortic valvulotomy and pulmonary arterioplasty in 2, double arch reconstruction in 2, and simple patch aortoplasty with plans for subsequent pulmonary arterioplasty and ventricular septal defect closure in 1. Results demonstrate that in patients with a hypoplastic ascending aorta, this radical method of palliation can result in growth of right and left heart structures and thus provides the possibility of biventricular repair.