Editor’s Note: Genetic testing for ARVC is offered through AU Health’s Cardiology Department.
A two-sentence email from her cousin changed Kathy Dexter’s life and gave her a mission.
“Hey – wanted to catch you up on what we are learning about heart issues in our family. Our daughter has been diagnosed with a very rare disease – Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC), which is a genetic disease.”
Kathy Dexter is encouraging physicians to explore a patient’s family history after learning of her own family’s history of Arrhythmogenic Right Ventricular Cardiomyopathy. Exploring risk factors for the condition has enabled family members to make lifestyle changes that reduce their risk of sudden cardiac arrest.
Then Dexter, the Assistant Dean of Clinical Practice at Augusta University and physician assistant, had a heart scare of her own: chest pains, palpitations, shortness of breath and severe hypertension that led her to take an ambulance to the ER. A cardiac catheterization showed that she had a partial blockage in a coronary artery, but no signs of ventricular dysplasia. She had a complete cardiac workup locally. Subsequent treatment of a hiatal hernia, where the stomach pushes up through the diaphragm, reduced her symptoms.
Dexter, a physician assistant, wrote about her experience in an article titled “Arrhythmogenic Right Ventricular Cardiomyopathy: A Case of Mistaken Identity” in Clinical Advisor.
“My point in writing the article was just to raise awareness,” she said.
Dexter’s family history of sudden cardiac arrest goes back to at least both of her grandfathers, who died at 59 and 60, as well as her father, who was in his 50s.
Her cousin’s daughter, the one mentioned in the email, was only 45 and very active. She had been working out at home and collapsed in her front yard. A neighbor, who was an anesthesiologist, was able to perform CPR until she could get to the hospital and saved her life.
Other family members also began having heart problems. Dexter and her family began wondering if there was a link.
They got genetic testing and some tested positive for a particular gene that is involved in the formation of myocytes in the heart.
“(ARVC is) a condition of the heart muscle. It’s not cardiovascular, so it has nothing to do with the vessels of the heart. It has to do with the muscles that make up the heart,” Dexter said. “What happens is, instead of the muscle cells (myocytes) regenerating like they’re supposed to, they die and eventually turn into fibrotic tissue. Fibrotic tissue can’t expand and contract like the heart needs to. When you have that fibrotic tissue, the ventricles can’t contract anymore. People go into heart failure, or they have fatal heart arrythmias, and they have sudden cardiac arrest and die.”
In many cases, there are no warning signs – the only symptom is a sudden cardiac arrest.
The condition can be linked to a mutation in the desmosomal protein (DSP) gene, which, according to the National Library of Medicine, can be attributed to one copy of an altered gene, which is why it tends to run in families. Several other gene mutations have been implicated in ARVC.
Several of Dexter’s family members underwent genetic testing, which has a specialized program dedicated to ARVC and ARVD (arrhythmogenic right ventricular dysplasia).
Dexter tested negative for the gene, but 12 members of her extended family tested positive. She said if you have the gene, you may get the disease that creates fibrous tissues in the ventricles of the heart, though you may not have sudden cardiac arrest. The key is to continue to follow up with a cardiologist so that disease progression can be monitored. Some people who are positive for the gene will not develop dysplasia. It is impossible to tell who will and who won’t, but participation in competitive sports or activities that stress the heart such as marathon running increase the risk.
Lifestyle changes can help reduce the progression of this often-undiagnosed disease.
The only cure for the disorder is a heart transplant. However, the symptoms can be managed with medication, implanted cardioverter defibrillators (ICD), and cardiac ablation to destroy defects in the electrical conduction system of the heart.
She hopes her article speaks to primary care providers, to encourage them to explore genetic testing with patients who have heart problems and a family history of sudden cardiac arrest.
“This can occur without warning. The person may have no risk factors and have no warning signs. For my family, it has been a long, scary journey,” Dexter said. “The people who have tested positive have changed their lifestyle, so that they have less risk of having that sudden cardiac arrest and having the disease progress.”
