Catheter ablation of atrioventricular junction via retrograde route in a patient with single ventricle.

Radiofrequency catheter ablation of the atrioventricular junction (AVJ) was performed by the retrograde route in a 19-year-old woman with atrial fibrillation and single ventricle following the bidirectional Glenn procedure. Two energy applications resulted in complete atrioventricular block and dependence on an epicardial ventricular pacemaker.

Early developmental outcome after the Norwood procedure for hypoplastic left heart syndrome.

OBJECTIVE: To assess intellect and adaptive behavior in children with hypoplastic left heart syndrome (HLHS) who had undergone at least two surgical stages of the Norwood procedure. METHODS: Fourteen children with HLHS >3 years of age participated in the study. The patients underwent intelligence quotient (IQ) testing, and their parents were interviewed regarding their children's adaptive behavior. Results were compared with those of 10 family controls. Outcomes were studied for possible correlation with perioperative variables. RESULTS: Among the HLHS patients, the median scores for full scale IQ and adaptive behavior were 88 and 91, respectively (normal = 100 +/- 15). One child met criteria for mental retardation. Family controls scored generally higher than did HLHS patients, but only differences in adaptive behavior were statistically significant. A negative correlation was found between stage I circulatory arrest time and full scale IQ. CONCLUSIONS: Children with HLHS most often function in the low-normal range of intelligence and adaptive behavior. A prolonged circulatory arrest time may result in decreased intellectual function.

Survival and risk factor analysis for the Norwood procedure for hypoplastic left heart syndrome.

The optimal approach to hypoplastic left heart syndrome (HLHS) is controversial. The palliative Norwood operation, cardiac transplantation, and no surgical intervention have all been advocated. Centers that perform the Norwood operation have met with varied results, and conflicting reports exist regarding factors predictive of stage I outcome. From January 1990 to January 1996, 67 patients with HLHS were admitted with intent to perform the staged Norwood procedure. Fourteen patients did not undergo surgery. In the 53 patients treated surgically, outcome was reviewed, and 10 potential risk factors for first stage mortality were analyzed. Forty-one infants survived the Norwood I operation to hospital discharge (77% of the surgically treated patients and 61% of the entire group, including those who did not undergo operation) with 6 additional deaths 3 to 5 months after operation. Univariate analysis showed cardiopulmonary bypass time and circulatory arrest time to be significant risk factors for hospital mortality. Multivariate analysis revealed only cardiopulmonary bypass time as significant (p <0.01). Of the 15 prenatally diagnosed newborns who underwent surgery, 11 survived (p = 0.72). Ten of 11 patients with preoperative organ damage survived (p = 0.42). Among the 35 bidirectional Glenn (Norwood II) and Fontan (Norwood III) procedures performed, there were 2 deaths. The 5-year actuarial survival for patients who underwent operations was 61%. The Norwood procedure is a favorable option for the infant with HLHS. Surgical survival may be affected by a prolonged cardiopulmonary bypass time, but is not affected by other factors analyzed, including prenatal diagnosis and preoperative organ damage.

Survival of MHC-deficient mouse heterotopic cardiac allografts.

The immunologic mechanisms involved in the destruction of murine cardiac allografts were evaluated using MHC-deficient mice. Specifically, we examined the survival of immediately vascularized heterotopic adult cardiac grafts deficient in MHC class I, MHC class II, or both MHC class I and II antigens following transplantation to allogeneic hosts. We observed indefinite cardiac graft survival when donors lacked MHC class II or both MHC I and II antigens. In parallel experiments, we studied the survival of cardiac grafts harvested from normal donors in recipients severely depleted of either CD4 (class II-deficient mice) or CD8 (class I-deficient mice) T cells. Graft survival was dramatically prolonged in the absence of CD4 but not CD8 T cells. Collectively, our results demonstrate that the interaction of host CD4 T cells with donor class II antigens is critical to the rejection of murine cardiac grafts.