When George Michael passed away on December 25, his death was initially categorized as “unexplained but not suspicious.” Today, the coroner investigating Michael’s death revealed that the singer died from natural causes, People reports, including cardiomyopathy with myocarditis and fatty liver.
To understand these conditions—and just how common they are—Health spoke with Brian Choi, MD, co-director of Advanced Cardiac Imaging at the George Washington University School of Medicine and Health Sciences. (Dr. Choi did not treat Michael.)
Cardiomyopathy and myocarditis can both be causes of heart failure, says Dr. Choi, a broad term used to describe the heart’s inability to pump as much blood as it should. In dilated cardiomyopathy, the heart’s blood flow is decreased because its left ventricle becomes enlarged and weakened.
In the United States, the prevalence of dilated cardiomyopathy is estimated to be about 1 in 2,500 people. The condition usually develops in the third or fourth decade of life, says Dr. Choi, but it’s more likely to cause serious problems as one gets older.
The most common type of dilated cardiomyopathy is idiopathic—meaning there is no obvious cause. But the condition can also be triggered by lifestyle or environmental factors, such as coronary artery disease, heavy alcohol use, or exposure to amphetamines, cocaine, certain toxins, or chemotherapy drugs.
Other chronic health conditions, such as diabetes, thyroid disease, and HIV can also contribute to the development of cardiomyopathy. “When someone presents with a cardiomyopathy, we screen for all of these things to figure out exactly what are the possible causes,” Dr. Choi says. “Sometimes we still can’t figure it out, and we need a biopsy to look at the heart muscle itself.”
But in Michael's case, says Dr. Choi, it sounds as if the coroner has attributed the singer's cardiomyopathy to myocarditis—an inflammation of the heart wall that is usually caused by one of several common viruses. (Fatty liver disease, he says, has many possible causes, and may or may not also be related to these heart conditions.)
“When a virus settles into the body, it’s usually attacked by the immune system,” Dr. Choi explains. “But sometimes there can be an autoimmune effect, when the immune system attacks the heart instead of the virus.” For some people, their hearts recover quickly—but for others, their hearts becomes weaker and start to dilate, or become bigger, as a result.
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Doctors aren’t sure why some people have this reaction, but they suspect that genetics may play a role. “For the majority of people who get these viruses, nothing happens to their heart,” says Dr. Choi.
Myocarditis is rarely related to lifestyle factors, says Dr. Choi—and, for the most part, both dilated cardiomyopathy and myocarditis are “rare events that are typically out of one’s control.”
From a prevention standpoint, people should still focus on avoiding the more common causes of heart failure—such as high blood pressure, uncontrolled diabetes, lack of exercise, poor diet, smoking, and excessive alcohol consumption. “If there’s a public health message to be shared, it’s that these risk factors—which we actually do have control over—contribute to heart failure much more than getting a virus or developing cardiomyopathy,” he says.