Ventricular function deteriorates with recurrent coarctation in hypoplastic left heart syndrome

Abstract

Background: Recurrent coarctation (re-CoA) after stage I palliation in hypoplastic left heart syndrome (HLHS) is deleterious. We studied whether re-CoA had an effect on ventricular systolic function.

Methods: Retrospectively reviewed were HLHS patients surviving stage I Norwood palliation (stage I) and cavopulmonary shunt (CPS) between January 2004 and February 2007. Echocardiographic right ventricular fractional area change (RV-FAC) was used to evaluate ventricular systolic function after stage I, before CPS, and before Fontan procedures. Cardiac catheterization and magnetic resonance imaging data before CPS were reviewed to assess re-CoA, using a coarctation index (CI = isthmus diameter/descending aortic diameter).

Results: Fifty-one patients were included, and 21 had a CI of less than 0.75 (mean, 0.82 +/- 0.19; 21). Twelve patients required arch balloon dilation between CPS and Fontan. The change of RV-FAC for all patients between stage I and CPS was -2.2% +/- 9.6%. Pearson correlation coefficient demonstrated a significant correlation between lower CI values and lower RV-FAC at the pre-CPS echocardiogram (r = .35, p = 0.03); and lower CI values and greater decrease in RV-FAC between stage I and pre-CPS evaluation (r = 0.40, p = 0.018). At follow-up pre-Fontan, RV-FAC for patients who underwent balloon dilation for re-CoA recovered to a level that was inferior but not significantly different from that of patients who did not need balloon dilation.

Conclusions: Recurrent aortic arch obstruction after stage I for HLHS is associated with worse RV systolic function at the time of stage II operation. Timely intervention on the re-CoA results in recovery of RV function.

Fig 1.

Mean change in right ventricular fractional area change (RV-FAC) for patients with recurrent coarctation was calculated using a coarctation index (CI) of 0.75 or higher as a cutoff value. Patients with a CI of less than 0.75 had a significantly lower RV-FAC at the pre-cavopulmonary shunt (CPS) evaluation than patients with a CI of 0.75 or higher. (Stage I = Norwood palliation.)

Fig 2.

The correlation is shown between coarctation index (CI) values and the difference in right ventricular function fractional area change (RV-FAC) between the post-stage I evaluation and the pre- cavopulmonary shunt (CPS) evaluation (ΔS1-S2 RV-FAC). A lower CI is associated with a greater decrease in RV function between stage I discharge and pre-CPS evaluation

Fig 3.

For patients who underwent balloon dilation for recurrent coarctation, mean right ventricular-fractional area change recovers to a level at the pre-Fontan assessment that is not significantly different from that of patients who did not need balloon dilation for recurrent coarctation. (CPS = cavopulmonary shunt.)