Senning Procedure for Physiological Atrial Inversion With Left Atrial Isomerism

We present the case of an infant with left atrial isomerism with complex pulmonary and systemic venous connections that resulted in physiological parallel circulation in the setting of ventriculoarterial concordance who was surgically treated using the Senning procedure. This case highlights a rare cause for cyanosis due to poor mixing from a parallel circulation and an issue with nomenclature. (Level of Difficulty: Advanced.).

Reports of 2 Rare Associations of Hypoplastic Left Heart Syndrome

This report describes 2 contrasting yet rare associations of hypoplastic left heart syndrome, 1 in a patient with pulmonary valve stenosis that was successfully surgically palliated and the other in a patient with an intact atrial septum and stenotic bilateral levoatriocardinal veins who was offered comfort care. These cases underscore the point that although both infants were born with hypoplastic left heart syndrome, the outcomes can dramatically differ as a result of anatomic and physiological variables. (Level of Difficulty: Advanced.)

Development of quality metrics for ambulatory pediatric cardiology: Transposition of the great arteries after arterial switch operation

OBJECTIVE

To develop quality metrics (QMs) for the ambulatory care of patients with transposition of the great arteries following arterial switch operation (TGA/ASO).

DESIGN

Under the auspices of the American College of Cardiology Adult Congenital and Pediatric Cardiology (ACPC) Steering committee, the TGA/ASO team generated candidate QMs related to TGA/ASO ambulatory care. Candidate QMs were submitted to the ACPC Steering Committee and were reviewed for validity and feasibility using individual expert panel member scoring according to the RAND-UCLA methodology. QMs were then made available for review by the entire ACC ACPC during an "open comment period." Final approval of each QM was provided by a vote of the ACC ACPC Council.

PATIENTS

Patients with TGA who had undergone an ASO were included. Patients with complex transposition were excluded.

RESULTS

Twelve candidate QMs were generated. Seven metrics passed the RAND-UCLA process. Four passed the "open comment period" and were ultimately approved by the Council. These included: (1) at least 1 echocardiogram performed during the first year of life reporting on the function, aortic dimension, degree of neoaortic valve insufficiency, the patency of the systemic and pulmonary outflows, the patency of the branch pulmonary arteries and coronary arteries, (2) neurodevelopmental (ND) assessment after ASO; (3) lipid profile by age 11 years; and (4) documentation of a transition of care plan to an adult congenital heart disease (CHD) provider by 18 years of age.

CONCLUSIONS

Application of the RAND-UCLA methodology and linkage of this methodology to the ACPC approval process led to successful generation of 4 QMs relevant to the care of TGA/ASO pediatric patients in the ambulatory setting. These metrics have now been incorporated into the ACPC Quality Network providing guidance for the care of TGA/ASO patients across 30 CHD centers.

Ventricular morphology is a determinant of diastolic performance in patients with single ventricle physiology undergoing stage 3 palliative surgery

Patients with single ventricle anatomy undergo staged surgical palliation which results in pulmonary and systemic circulations in series with a single systemic pump. Single right ventricular morphology has been found to be an independent risk factor for worse survival. We sought to compare patients with single left (SLV) and single right (SRV) ventricular morphology to identify hemodynamic differences that may contribute to worse survival in patients with a single right ventricular. Single center, retrospective review of invasive hemodynamic data. All patients with single ventricle anatomy who underwent superior cavo-pulmonary anastomosis (Stage 2 palliation) and/or total cavo-pulmonary anastomosis (Stage 3 palliation) from August 1995 through May 2011 were identified. Patients were compared over time, and SLV and SRV patients were compared. Seventy-nine single ventricle patients (56 % SRV) underwent staged palliation and were analyzed. There was no difference in overall mortality (12 % SLV, 11 % SRV). There was no difference in hemodynamics at pre-Stage 2 catheterization between ventricular morphology, but SRV patients had higher ventricular end-diastolic pressure at pre-Stage 3 catheterization (7.6 vs. 6.4 mmHg, p = 0.026). End-diastolic pressure decreased after Stage 2 surgery for SLV patients, but not SRV patients. Intrinsic differences in morphology, function, and response to performing as the systemic ventricle between single right and left ventricles may lead to an elevated ventricular end-diastolic pressure. This could limit passive flow through the pulmonary circuit and coronary perfusion after Stage 3 palliation and potentially lead to poorer long-term performance for SRV patients.

Right-ventricular global longitudinal strain may predict neo-aortic arch obstruction after Norwood/Sano procedure in children with hypoplastic left heart syndrome

Neo-aortic arch obstruction (NAAO) is a common complication following the Norwood/Sano procedure (NP) for hypoplastic left heart syndrome (HLHS) and is associated with increased morbidity and mortality. However, there is currently no objective method for predicting which patients will develop NAAO. This study was designed to test the hypothesis that hemodynamic changes from development of NAAO after NP in patients with HLHS will lead to changes in myocardial dynamics that could be detected before clinical symptoms develop with strain analysis using velocity vector imaging. Patients with HLHS who had at least one cardiac catheterization after NP were identified retrospectively. Strain analysis was performed on all echocardiograms preceding the first catheterization and any subsequent catheterization performed for intervention on NAAO. Twelve patients developed NAAO and 30 patients never developed NAAO. Right ventricular strain was worse in the group that developed NAAO (-6.2 vs. -8.6 %, p = 0.040) at a median of 59 days prior to diagnosis of NAAO. Those patients that developed NAAO following NP were significantly younger at the time of first catheterization than those that did not develop NAAO (92 ± 50 vs. 140 ± 36 days, p = 0.001). This study demonstrates that right ventricular GLS is abnormal in HLHS patients following NP and worsening right ventricular strain may be predictive of the future development of NAAO.

Head and neck vessel size by angiography predicts neo-aortic arch obstruction after Norwood/Sano operation for hypoplastic left heart syndrome

OBJECTIVES

To identify and predict neo-aortic arch obstruction (NAAO) in children after Norwood/Sano operation (NO) for hypoplastic left heart syndrome (HLHS).

BACKGROUND

NAAO is associated with morbidity and mortality after NO for HLHS and no objective measure has predicted the initial occurrence of NAAO. Computational flow models of aortic coarctation demonstrate increased wall shear stress (WSS) in vessels proximal to the coarctation segment, which we believe also occurs with NAAO. These vessels respond by increasing their luminal diameter to maintain normal WSS. We hypothesized that the relative increase in diameters of head and neck vessels to the isthmus, as measured by angiography, would identify hemodynamically significant NAAO and predict future NAAO.

METHODS

Retrospective review of patients with HLHS and at least one catheterization with aortic angiography after NO. Diameters of head and neck vessels were totaled and divided by the isthmus diameter to give a head and neck index (HNI), which was compared to coarctation index (CI) for identifying and predicting future NAAO.

RESULTS

Forty-four patients were identified, 17 with and 27 without NAAO. Receiver operator characteristic analysis using a value for CI ≤0.5 showed a sensitivity of 47% and specificity of 89%. For HNI, a value >2.65 gave a sensitivity of 77% and specificity of 93%. Three patients who developed NAAO after their initial catheterization had CI >0.5, but abnormally high HNI >2.65.

CONCLUSIONS

HNI is a more robust indicator of hemodynamically significant NAAO than CI and may predict its future occurrence after NO for HLHS.

Anatomically corrected malposition of the great arteries

We present cardiac magnetic resonance images of a 6-year-old with a suspected great artery abnormality in the setting of mesocardia, atrial situs solitus, D-looping of the ventricles, and anatomically corrected malposition of the great arteries with subaortic and subpulmonary conus.

Cardiac transplantation after the Fontan or Glenn procedure

OBJECTIVES

The purpose of this study was to review the clinical course and outcome of cardiac transplantation after a failed Glenn or Fontan procedure.

BACKGROUND

Late complications of the Glenn or Fontan procedure, including ventricular failure, cyanosis, protein-losing enteropathy, thromboembolism, and dysrhythmias often lead to significant morbidity and mortality. If other therapies are ineffective, cardiac transplantation is the only therapeutic recourse. Transplantation in this unique population presents significant challenges in the operative and perioperative periods.

METHODS

The anatomic diagnoses, previous operations, clinical status, and indications for transplantation were characterized in patients transplanted after a Glenn or Fontan procedure. Outcomes after transplantation, including postoperative complications and mortality, were reviewed. Comparisons were made between survivors and nonsurvivors.

RESULTS

Primary orthotopic cardiac transplantation was performed in 35 patients (mean age 15.7 +/- 8.5 years) with a mean follow-up of 54 +/- 46 months. A total of 11 patients had undergone a Glenn shunt and 24 patients a Fontan procedure. Indications for transplantation were a combination of causes including ventricular dysfunction, failed Fontan physiology, and/or cyanosis. Ten patients died <or=2 months after transplantation; nine of the deaths occurred in the Fontan patients. Overall, one-year survival was 71.5%, and five-year survival was 67.5%. Survival was not significantly different between patients transplanted after a Glenn or Fontan procedure and patients transplanted for other etiologies.

CONCLUSIONS

Cardiac transplantation can be performed successfully in patients with end-stage congenital heart disease after a Glenn or Fontan procedure, with outcomes similar to transplantation for end-stage heart failure secondary to other etiologies.

Endovascular stent implantation in the pulmonary arteries of infants and children without the use of a long vascular sheath

Endovascular stent implantation for pulmonary artery stenosis requires the use of a long, large-bore vascular sheath to insure precise implantation without embolization or malposition. A long vascular sheath may be difficult to position and usage may be associated with vascular compromise and/or hemodynamic embarrassment, especially in infants and small children. We report a new technique for pulmonary artery endovascular stent implantation without the use of a long sheath. From December 2000 to May 2001, 10 patients underwent implantation of 13 Palmaz Corinthian premounted biliary transhepatic stents for pulmonary artery stenosis. Median age was 0.8 years (range, 0.5-18.5) and median weight was 11.8 kg (range, 4.6-65). Patient diagnoses were tetralogy of Fallot (five), double outlet right ventricle (three), branch peripheral pulmonary artery stenosis (two), single ventricle s/p cavopulmonary shunt (one), and truncus arteriosus (one). All Palmaz Corinthian stents were delivered uncovered on Cordis Opta LP balloon catheters via short sheaths (6-7 Fr); super-stiff guidewires were not always necessary. These stents, with a maximal expanded diameter of 12 mm, were placed for peripheral pulmonary artery stenosis as a definitive procedure or at the pulmonary artery bifurcation in patients who were expected to undergo future open heart surgery. The stents were initially implanted on 4, 6, or 8 mm balloon catheters and further expanded if needed. Stents were placed in the right pulmonary artery alone in three patients, left pulmonary artery alone in four patients, and side-by-side stents were implanted simultaneously in three patients. All thirteen stents were implanted successfully in the desired location without stent malposition or embolization. Mean angiographic diameter increased from 2.5 +/- 1.5 to 5.7 +/- 1.4 mm (P < 0.01) and peak systolic ejection gradients decreased from 44 +/- 22 to 14 +/- 11.6 mm Hg (P < 0.01). The uncovered delivery of the premounted Palmaz Corinthian stent allowed for precise and safe endovascular stent implantation without the hemodynamic and technical problems associated with long vascular sheath usage. This technique is useful for the palliation of proximal pulmonary artery stenosis and is effective definitive treatment for peripheral pulmonary artery stenosis in small infants and children.