Thrombocytosis in the Setting of Isomerism and a Functionally Univentricular Heart

Timing of Fontan Completion in Children with Functionally Univentricular Hearts and Isomerism: The Impact of Age, Weight, and Pre-Fontan Arterial Oxygen Saturation

Isomerism, or heterotaxy, impacts morbidity and mortality after various stages of univentricular palliation. Timing of Fontan completing in these patients based on preoperative factors has not been investigated previously. The aim of this study was to determine the impact of preoperative factors on various outcomes including length of hospital stay and duration of chest tubes. A cross-sectional study was conducted. Patients with isomerism having undergone Fontan at the Children's Hospital of Wisconsin between 1998 and 2014 were identified. Preoperative, operative, and postoperative data were collected on these patients. Linear regression analysis was conducted to determine preoperative characteristics associated with various postoperative outcomes. Receiver operator curve analysis was also performed to determine the sensitivity and specificity of age and pre-Fontan arterial oxygen saturation in predicting increased length of hospitalization and increased duration of chest tubes. Younger age and lower pre-Fontan arterial oxygen saturation were associated with increased length of hospitalization while younger age, lower pre-Fontan arterial oxygen saturation, interrupted inferior caval vein, and worse pre-Fontan atrioventricular valve regurgitation were associated with increased length of chest tubes. Age, arterial oxygen saturation, pulmonary arteriovenous malformations, interruption of the inferior caval vein, and atrioventricular valve regurgitation should all be taken into consideration when timing Fontan completion in patients with isomerism. Arterial oxygen saturations between 82 and 84% with an approximate age of 3 years appear to be a time at which it is reasonable to consider Fontan in patients with isomerism.

Cardiopulmonary Exercise Testing in Fontan Patients With and Without Isomerism (Heterotaxy) as Compared to Patients With Primary Ciliary Dyskinesia and Subjects With Structurally Normal Hearts

Isomerism, also known as heterotaxy, is a clinical entity that impacts multiple organ systems both anatomically and functionally. The airways and lungs are involved in a great number of these patients, leading to increased sinopulmonary symptoms, increased need for oxygenation, and increased postoperative ventilatory support. Additionally, these patients often have congenital heart disease requiring Fontan palliation. What has not been previously described, and is the focus of this study, is the results of cardiopulmonary exercise testing in those who have undergone Fontan palliation with and without isomerism. We have now compared these finding with those from patients with primary ciliary dyskinesia, as many patients with isomerism have ciliary dyskinesia. We identified patients having the Fontan circulation with and without isomerism who had undergone cardiopulmonary exercise testing, comparing the findings from healthy individuals undergoing exercise, and a comparable number of individuals with primary ciliary dyskinesia but no congenital heart disease. We were able to include a total of 68 patients in our study, with 17 in each of the four groups. Cardiopulmonary exercise testing yielded the best results in healthy patients. All patients with the Fontan circulation demonstrated mixed pulmonary disease, although those with isomerism had greater FVC and FEV1. Exercise times did not differ, although peak consumption of oxygen was greater in those with isomerism. Those with ciliary dyskinesia had only obstructive pulmonary disease and had the lowest FEF25-75 between all groups. Those with isomerism had a lesser degree of obstructive pulmonary disease when compared to those with primary ciliary dyskinesia. Patients with the Fontan circulation with and without isomerism have relatively subtle differences in their cardiopulmonary exercise testing, with both groups demonstrating restrictive lung disease. In regard to obstructive lung disease, those with isomerism tend to be more similar to the patients with primary ciliary dyskinesia than those with the Fontan circulation but without isomerism. The results are likely limited by selection bias and highlight the need for multicentric efforts to characterize cardiopulmonary exercise testing in those patients with pulmonary isomerism.

Characteristics of Hospitalizations for the Glenn Procedure in Those With Isomerism Compared to Those Without

Isomerism, also known as heterotaxy, is a unique clinical entity in which there are mirror imaged findings in the thoracic. In the abdomen, the arrangement of organs can be random. The anatomic findings also have functional consequences. Isomerism has been known to increase morbidity and mortality in those with functionally univentricular hearts. The aim of this study was to determine the impact of isomerism on the Glenn hospitalization. Data from the 1997 to 2012 Kids' Inpatient Database were utilized for this cross-sectional study. Admissions during which a Glenn procedure was done were identified. Next, these admissions were separated into those with and without isomerism. Admission characteristics were then compared in a univariate fashion as well as by regression analysis. Length of hospitalization, cost of hospitalization, extracorporeal membrane oxygenation, and inpatient mortality were the outcomes of interest. A total of 4959 admissions with a Glenn procedure were identified. Of these, 450 were associated with isomerism. The median age at which the Glenn procedure was done was 10 and 13 months in those without and with isomerism, respectively. Neither univariate nor regression analysis demonstrated any significant difference in length of hospitalization, cost of hospitalization, need for extracorporeal membrane oxygenation, and inpatient mortality between those with and without isomerism. Isomerism does not impact the characteristics of the Glenn hospitalization. Those with isomerism did tend to be older when they underwent the Glenn procedure.

Radiologic Considerations in Heterotaxy: The Need for Detailed Anatomic Evaluation

So-called "heterotaxy" is a laterality defect characterized by isomerism of the thoracic organs and random arrangement of the abdominal organs. These findings go beyond anatomic curiosity and have functional implications. It is, thus, of the utmost importance to be able to properly identify these findings. Radiologic studies can be invaluable in determining anomalies in the central nervous, pulmonary, cardiovascular, gastrointestinal, genitourinary, and immunologic systems in patients with isomerism. Here, we review findings associated with isomerism and their importance in the setting of isomerism with the aim of ensuring that radiologists effectively describe findings in these patients and that cardiologists understand the wide variety of congenital malformations that may be present.