How do you mend a broken heart? Researchers at the Translational Genomics Research Institute (TGen) and Barrow Neurological Institute may have opened the door to finding a way.
In a breakthrough, teams from the Phoenix-based organizations have identified genetic risk factors that are linked to stress-induced cardiomyopathy (SIC), a rare type of heart disease. Its patients generally show no symptoms until they suffer some form of intense emotional or physiological distress. For this reason, the disorder is sometimes referred to as “broken heart syndrome.”
According to the American Heart Association, SIC may be misdiagnosed as a heart attack because the symptoms and test results are similar. More common in women, a part of the heart temporarily enlarges and doesn’t pump well while the rest of the heart functions normally or with even more forceful contractions. While tests show dramatic changes in rhythm and blood substances typical of a heart attack, there’s no evidence of blocked heart arteries in broken heart syndrome.
SIC, also known as or Takotsubo cardiomyopathy, is a poorly understood and likely under-diagnosed phenomenon. In some cases, a drug used to treat a heart attack actually could worsen the condition of patients with SIC.
In a study published in the journal Neurosurgery, researchers reported on the identification of new genetic risk factors through the use of the powerful approach of genomic sequencing. Knowing which patients harbor the genes associated with SIC could help guide their care and treatment before and after they suffer a life-threatening stressor that induces SIC.
Using ultra-high resolution cameras and supercomputers, researchers identified the suspect genes by next generation DNA sequencing, which was done through essentially spelling out the billions of bits of information in the genomes of seven women who exhibited SIC following a brain aneurysm.
“We propose that SIC is an example of a hidden heart disease with a distinct physiological trigger, and suggest that alternative clinical approaches to these patients may be warranted,” says Dr. Yashar Kalani, a chief resident in neurological surgery, assistant professor at Barrow at Dignity Health St. Joseph’s Hospital and Medical Center, and the study’s lead author.
Patients who volunteered for the study were among the 21 victims of hemorrhagic stroke treated at Barrow between 2005 and 2013, and diagnosed with SIC. None had significant prior cardiac history. Barrow is a leading neurotrauma center with more than 300 hemorrhagic stroke patients each year.
“We hypothesize that patients at highest risk for SIC likely live in a compensated state of cardiac dysfunction that manifests clinically only after the heart muscle is stressed,” says Matt Huentelman, associate professor of TGen’s Neurogenomics Division, and the senior author of the study. “We have identified a series of rare genetic changes associated with this disease that may be used for early identification of patients at risk.”
Contributing to this article were Carmelle Malkovich, media relations manager of Dignity Health, and Steve Yozwiak, TGen senior science writer.
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