Imaging and Outcome
By comparing magnetic resonance and echocardiographic images of the heart with the medical history of people with HLHS, physicians and scientists will be able to develop better methods of assessing heart function and predicting outcomes.
Children with hypoplastic left heart syndrome (HLHS) are usually treated with a multistage cardiac surgery. The final operation in the treatment plan is called a Fontan operation, after which the patient has a "Fontan circulation."
People with HLHS and a Fontan circulation rely on the right ventricle to provide their entire cardiac output, produce sufficient blood pressure and ensure blood flow to all of their organs. As the right ventricle was not designed for this task, people with HLHS are likely to develop a progressive decline in right ventricular function and performance.
In the Todd and Karen Wanek Family Program for HLHS at Mayo Clinic, physicians and scientists are working together to better understand the natural history and predictors of long-term right ventricular performance in people with HLHS. To do this, researchers are focused on improving how cardiac performance is assessed so that declines in cardiac function can be detected — and therefore managed — as early as possible.
The primary objective of the imaging and outcome team in the Program for HLHS is to:
- Improve clinicians' ability to noninvasively assess right ventricular function in HLHS, as well as in other complex forms of congenital heart disease where the right ventricle is required to support systemic (aortic) circulation
Additional objectives include:
- Improving the understanding of the natural history and complications encountered by people with HLHS after surgical palliation
- Predicting which single right ventricle patients may be at greatest risk of developing clinically significant right ventricular dysfunction
- Defining the frequency with which first-degree relatives (biological parents and siblings) of people with HLHS have undetected congenital cardiac malformations
- Describing the cardiac phenotype (anatomical and functional) associated with the genotypes defined by studies in the program's human genetics component
- Supporting eventual clinical trials in cardiac stem cell therapy for the failing right ventricle by defining the best clinical algorithm for quantitating systemic right ventricular performance
In pursuit of these objectives, investigators are:
Constructing a detailed HLHS digital database. To enable clinical information to be correlated with novel imaging data — which will assist in the discovery of predictors of late right ventricular performance and dysfunction — researchers are creating a robust digital database.
For each HLHS patient, the database will include comprehensive clinical descriptions of the cardiac malformation; clinical and surgical history; clinical and functional status at the time of study; cardiac biomarker levels; results of echocardiography and cardiac magnetic resonance imaging (cMRI) scans; and detailed descriptions of genetic and cardiopoietic stem cell profiles as obtained by studies in the program's regenerative strategies component.
- Obtaining detailed cardiac images. To quantitate right ventricular performance in people with HLHS, investigators are contemporaneously conducting echocardiographic examinations and cMRI scans. Imaging results are then correlated to the digital database (described above) in an effort to determine the best noninvasive strategy for repetitive assessment of right ventricular performance.
- Determining the frequency of cardiac defects in relatives. Some evidence suggests that relatives of people with HLHS may be at an increased risk of having subtle structural heart disease. By performing a standard transthoracic echocardiogram, researchers are trying to determine the frequency of undiagnosed congenital cardiac malformations in those family members.
- Linking images to genetics. After gathering imaging and clinical information from people with HLHS, researchers are correlating this data with the individual's molecular genetics profile and the characteristics of his or her patient-specific induced pluripotent stem cell-derived cardiac myocytes.
If you have questions about HLHS imaging and outcome research within the program or would like to learn more about research participation opportunities, please contact: