Cross sectional echocardiographic identification of hypoplastic left heart syndrome and differentiation from other causes of right ventricular overload

Congenital heart disease linked to maternal autoimmunity against cardiac myosin

Structural congenital heart disease (CHD) has not previously been linked to autoimmunity. In our study, we developed an autoimmune model of structural CHD that resembles hypoplastic left heart syndrome (HLHS), a life-threatening CHD primarily affecting the left ventricle. Because cardiac myosin (CM) is a dominant autoantigen in autoimmune heart disease, we hypothesized that immunization with CM might lead to transplacental passage of maternal autoantibodies and a prenatal HLHS phenotype in exposed fetuses. Elevated anti-CM autoantibodies in maternal and fetal sera, as well as IgG reactivity in fetal myocardium, were correlated with structural CHD that included diminished left ventricular cavity dimensions in the affected progeny. Further, fetuses that developed a marked HLHS phenotype had elevated serum titers of anti-β-adrenergic receptor Abs, as well as increased protein kinase A activity, suggesting a potential mechanism for the observed pathological changes. Our maternal-fetal model presents a new concept linking autoimmunity against CM and cardiomyocyte proliferation with cardinal features of HLHS. To our knowledge, this report shows the first evidence in support of a novel immune-mediated mechanism for pathogenesis of structural CHD that may have implications in its future diagnosis and treatment.

Left ventricular growth in selected hypoplastic left ventricles: outcome after repair of coarctation of aorta

BACKGROUND

Models that predict survival in neonates with left ventricular hypoplasia and critical aortic stenosis may not be applicable to neonates with left ventricular hypoplasia and coarctation.

METHODS AND RESULTS

We report 8 infants with severe aortic coarctation and left ventricular hypoplasia. Mean age was 18 days (range 1-48 days), and mean weight was 3.5 kg (range 2.7-4.3 kg). Associated diagnoses included mild aortic stenosis (4), ventricular septal defect (2), and venous anomalies (2). All had coarctation repair as a primary procedure (3 of these had concomitant intracardiac procedures); 7 had subsequent operations. All are alive and well 1.1-6.7 years (mean 3.1 years) after the first surgery. Progressive increases were observed in aortic and mitral diameters, and in left ventricular dimensions, areas, and volumes when the preoperative, earliest postoperative, and most recent echocardiograms were compared.

CONCLUSIONS

Despite severe left ventricular hypoplasia, a two-ventricle repair is possible in selected cases. The prognostic criteria for left ventricular hypoplasia in critical aortic stenosis may not be applicable to infant coarctation. Relief of coarctation may result in the growth of the very small left ventricle, especially when the aortic root and mitral diameters are satisfactory.

Biventricular repair approach in ducto-dependent neonates with hypoplastic but morphologically normal left ventricle

OBJECTIVES

Increased afterload and multilevel LV obstruction is constant. We assumed that restoration of normal loading conditions by relief of LV obstructions promotes its growth, provided that part of the cardiac output was preoperatively supported by the LV, whatever the echocardiographic indexes.

BACKGROUND

Whether to perform uni- or biventricular repair in ducto dependent neonates with hypoplastic but morphologically normal LV (hypoplastic left heart syndrome classes II & III) remains unanswered. Echocardiographic criteria have been proposed for surgical decision.

METHODS

Twenty ducto dependent neonates presented with this anomaly. All had aortic coarctation associated to multilevel LV obstruction. Preoperative echocardiographic assessment showed: mean EDLW of 12.4 +/- 3.03 ml/m2 and mean Rhodes score of -1.73 +/-0.8. Surgery consisted in relief of LV outflow tract obstruction by coarctation repair in all associated to aortic commissurotomy in one and ASD closure in 2.

RESULTS

There were 3 early and 2 late deaths. Failure of biventricular repair and LV growth was obvious in patients with severe anatomic mitral stenosis. The other demonstrated growth of the left heart. At hospital discharge the EDLVV was 19.4+/-3.12 ml/m2 (p = 0.0001) and the Rhodes score was -0.38+/-1.01 (p = 0.0003). Actuarial survival and freedom from reoperation rates at 5 years were 72.5% and 46%, respectively.

CONCLUSIONS

Biventricular repair can be proposed to ducto dependent neonates with hypoplastic but morphologically normal LV provided that all anatomical causes of LV obstruction can be relieved. Secondary growth of the left heart then occurs; however, the reoperation rate is high.

[Clinical and echocardiographic impact of neonatal aortic valvuloplasty]

OBJECTIVES

The selection of patients for balloon aortic valvuloplasty is a vital clinical challenge in neonatal aortic stenosis. The present study was designed to establish possible predicting factors for poor results after balloon therapy.

PATIENTS AND METHODS

2D echocardiographic, Doppler color and clinical variables (grade of cardiac failure, aortic "anulus", mitral anulus, left ventricular diameter, ascending aorta, instantaneous Doppler gradient, and grade of aortic regurgitation) were analyzed in 32 neonates submitted to balloon dilation at 22 +/- 18 days of life. The evaluations were conducted during three periods in respect to balloon therapy (A: before; B: immediately after, and C: mid-term follow-up). The outcome in both, B and C periods was defined as favorable (all survivors with Doppler gradient < or = 70 mmHg and no other intervention on the valve) and unfavorable (death, first stage of univentricularization, valvular replacement or survivors with Doppler gradient > 70 mmHg). Mean values between subgroups were compared by Wilcoxon test; unconditional logistic regression was used to analyze the impact of cardiac failure and anatomic variables (continuous, categorized or Z) on the outcome.

RESULTS

The Doppler gradient decreased from 70 +/- 28 to 34 +/- 14 mmHg after the valvuloplasty, and no changes were detected in the follow-up period (36 +/- 8 mmHg). An immediate favorable result was obtained in 72% of the patients; its consisted of 50% in period C. Nine neonates had an immediate unfavorable outcome (6 deaths and 3 with Norwood operation). In the follow-up, three patients had valvular replacement, one patient Doppler gradient > 70 mmHg and one patient with left ventricular endomyocardial abnormalities died. The severe cardiac failure (odds ratio: 33; CL 2.4-443; p = 0.008) and all categorized anatomic variables (aortic "anulus" < or = 6 mm; mitral anulus < or = 9 mm; ascending aorta < or = 8 mm; left ventricular diameter < or = 13 mm) were related with the immediate poor outcome. At 7.6 years, survival and freedom with no valvular replacement nor reintervention probability rates were 83% and 67%, respectively.

CONCLUSIONS

2D echo Doppler provides essential information about the anatomic and functional lesions coexisting with severe or critical aortic stenosis in neonates. Patients with left heart hypoplasia and severe heart failure should not be candidates for balloon valvuloplasty. The degree of residual aortic regurgitation and endomyocardial abnormalities of the left ventricle play an important role in the mid-term follow-up.

Conditions with right ventricular pressure and volume overload, and a small left ventricle: "hypoplastic" left ventricle or simply a squashed ventricle?

OBJECTIVES

We modeled the utility of preoperative potential left ventricular (LV) volume in predicting postoperative volume in conditions causing LV compression.

BACKGROUND

With right ventricular (RV) overload lesions, LV "hypoplasia" may be primarily due to compression by reverse septal bowing. If so, preoperative potential LV volume should correspond 1:1 with postoperative volume. The potential volume for a given endocardial circumference can be calculated from the maximal potential cross-sectional area (where A = circumference(2)/4pi) and LV length.

METHODS

We studied echocardiographic variables from 22 patients with RV overload lesions perioperatively.

RESULTS

Preoperative LV volume was 15.0 +/- 7.1 ml/m2 (59% of patients had a volume <15 ml/m2); potential volume was 20.0 +/- 9.8 ml/m2. Postoperative volume increased to 28.2 +/- 8.6 ml/m2 (100% of patients had a volume >15 ml/m2). Preoperative potential volume correlated well with, but generally underestimated, postoperative volume (r = 0.75, p < 0.0001). Postoperative increases in both LV circumference and length contributed to this discrepancy.

CONCLUSIONS

In RV overload lesions, LV "hypoplasia" is primarily due not to compression; rather it is due to underfilling. Even "hypoplastic" ventricles can achieve an adequate cavity after operation normalizes loading conditions. Both true and potential preoperative volume can predict postoperative volume well. However, potential volume, which is less prone to underestimating ventricular adequacy, may better help to determine suitability for biventricular repair in lesions of RV overload associated with a "hypoplastic" LV.

Echocardiographic estimation of critical left ventricular size in infants with isolated aortic valve stenosis

With the current trend to performing surgical valvotomy for infantile aortic stenosis without cardiac catheterization, there is a need to develop echocardiographic criteria for adequacy of left ventricular size. The echocardiograms and catheterization data of all 25 infants less than 3 months of age undergoing aortic valvotomy for isolated aortic valve stenosis from September 1980 through July 1990 were reviewed. Significant differences (p less than 0.05) between the survivors and nonsurvivors were noted for age at operation (30 +/- 28 vs. 3 +/- 1.5 days), mitral valve diameter (10.1 +/- 1.7 vs. 7.7 +/- 1.5 mm), left ventricular end-diastolic dimension (18.4 +/- 6.4 vs. 11.4 +/- 3 mm), left atrial dimensions (15.3 +/- 3.8 vs. 10 +/- 2.4 mm), left ventricular cross-sectional area on the parasternal long-axis echocardiogram (4 +/- 1.9 vs. 2 +/- 1.9 cm2) and angiographically determined left ventricular end-diastolic volume (43 +/- 23 vs. 11 +/- 5 ml/m2). There was no difference with respect to patient weight, body surface area, aortic root dimension or left ventricular ejection fraction. Left ventricular cross-sectional area less than 2 cm2 as measured on the parasternal long-axis echocardiogram was found in 5 of 7 nonsurvivors and 0 of 12 survivors, making this a risk factor for perioperative death (p less than 0.05). Left ventricular end-diastolic dimension less than 13 mm was found in 5 of 6 nonsurvivors and 2 of 17 survivors, making this another risk factor for early mortality (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)