Timely diagnosis of Fabry disease can prevent irreversible structural changes in the heart, a study reports.
In their research, “Echocardiographic Assessment of Patients with Fabry Disease,” a Canadian team reviewed the characteristics of heart abnormalities associated with Fabry disease. Their article appeared in the Journal of the American Society of Echocardiography.
The heart contains four chambers — the right and left atriums and the right and left ventricles. An atrium is smaller than a ventricle and has thinner, less muscular walls. A receiving chamber for blood, it is connected to the veins that carry blood to the heart.
The ventricles are the larger, stronger pumping chambers that send blood out of the heart. They are connected to the arteries that carry blood away.
The most common structural change in Fabry patients’ hearts is thicker left ventricle walls. Patients can have other heart abnormalities as well, however. These include an enlarged atrium, impaired function of atriums and ventricles, a heart valve disease, and a wider than normal aorta, the body’s main artery.
Doctors can use echocardiography to detect these problems. It provides them wtih a picture of the heart’s structural and functional abnormalities.
“A more precise and comprehensive characterization of Fabry cardiomyopathy using conventional and novel echocardiographic techniques may lead to earlier diagnosis, more accurate prognostication, and timely treatment,” the researchers wrote.
In Fabry patients, thicker left ventricle walls are caused by glycolipids building up in heart muscle fiber. Without treatment, the walls become thicker as the disease progresses. This hallmark is more common among men, and usually appears at an earlier age than in women.
Another manifestation of Fabry disease is thickening of papillary muscles — small ventricle muscles connected to valves — and valve function impairment. Fabry patients are more likely to have this abnormality than people with similar heart conditions. Still, enlarged papillary muscles are not enough by themselves to denote Fabry disease, the researchers reported.
A person with a thicker left ventricle wall is also likely to have a smaller right ventricle. This structural change promotes right ventricle dyfunction, which increases a person’s risk of hospitalization and death.
Some studies have reported that glycolipids can accumulate in atrium cells, which are responsible for the electrical stimulus that controls atrium beat rhythm. By changing the cells’ activity, the deposits can lead to irregular heartbeats and an enlarged atrium — a condition that occurs in about 30% of cases. There is also evidence that glycolipid deposits can cause atrium dysfunction regardless of other heart abnormalities.
In addition, about 57% of Fabry patients have thicker mitral valves and 47% thicker aorta valves. These abnormalities usually cause only mild valve dysfunction or valve disease, however.
Enzyme replacement therapy is the gold standard for treating Fabry disease. It reverses the effects of the faulty alpha-galactosidase A enzyme linked to the disease.
A number of clinical trials have shown that enzyme replacement therapy can reverse the heart manifestations of Fabry syndrome. But some studies have failed to show that the therapy’s benefits are long-lasting.
Whether it can ultimately lead to better disease outcomes also remains unclear.
The researchers suggested that timely detection of Fabry disease’s cardiac manifestations could improve enzyme replacement therapy’s effectiveness and give patients a better chance at heart recovery.
Using advanced imaging techniques such as three-dimensional echocardiography could help with this task and pave the way for additional therapy developments, they said.