|4/4/2013 11:10:00 AM|
Viral heart disease reasons unknown
|NewsTribune photo/Amanda Whitlock|
Unlike an arterial blockage that could impact a specific part of the heart, cardiomyopathy is a condition that affects the function of the entire heart. Some causes of cardiomyopathy are well understood, such as alcoholism, but doctors have a more limited understanding of viral cardiomyopathy, or heart failure induced by the same viruses linked to colds and flu.
|NewsTribune photo/Amanda Whitlock|
Think you can’t ‘catch’ heart disease? Think again. Cardiologist Steven Lome said some forms of heart failure are viral in origin, meaning the same viruses linked to colds, flu and mononucleosis can embed in the heart cells and cause trouble. Lome says not to worry: Many people will contract viral cardiomyopathy, recover quickly and never know they had it. Blockages resulting from bad diets and sedentary lifestyles, as well as bad genes, remain the biggest source of heart disease today.
James Nixon of Ottawa was so weak and short of breath he had trouble showering and getting dressed in the morning.
Nixon finally went to the emergency room in September 2011 and wasn’t terribly surprised when preliminary tests showed he had pneumonia.
What did surprise him was tests showed he also had congestive heart failure, or cardiomyopathy. Even more stunning, his doctor told him it surely was a virus — and maybe a household bug such as the flu — that cut down his heart function.
“I was pretty shocked,” Nixon said. “At that time, I was only 39 years old. That was the last thing I expected to hear when I went to the doctor.”
Most Americans understand that a bad diet and sedentary lifestyle can lead to arterial blockages that cause heart attacks and ischemic cardiomyopathy, or obstructive heart failure.
Not as many Americans know what Nixon has learned the hard way: Some forms of heart failure are non-ischemic — that is, not linked to blockages — and some strains can be acquired through the same contagions that cause colds or flu.
Steven Lome, a cardiologist who practices in Peoria and Peru, acknowledged that more than half of all heart diseases — and maybe up to 90 percent — are caused by blockages linked to bad lifestyles and bad genes. Nevertheless, he said, “It is still common for a weakened heart to be from non-obstructive causes.”
One known cause of non-ischemic cardiomyopathy is alcoholism.
“Alcohol is a big, major contributor,” Lome said. “As few as three or four drinks a day can cause somebody’s heart to weaken and cause alcoholic cardiomyopathy.
“But this is different in everybody,” he added. “I have one patient who drinks two 24-packs a day, and his heart is fine.”
Other causes are not as well understood, so doctors use the term “idiopathic cardiomyopathy” to describe heart failure induced by unknown or uncertain causes.
Doctors know, for example, that viruses can invade the heart cells and disrupt heart function. Research has linked heart failure to dozens of viruses including familiar ones such as hepatitis C, the H1N1 flu virus and Epstein-Barr, one of the viruses linked to mononucleosis.
Unfortunately, current technology does not allow doctors to diagnose which virus has caused a person’s heart to fail.
That was true for Nixon, whose family history is riddled with heart disease. Doctors were sure he had viral cardiomyopathy, but to this day no one can say just what bug bit him.
Chances are it was something familiar — and something that perhaps could have been avoided by washing hands or covering the mouth. As difficult as it is to completely avoid picking up these bugs, wiping them out poses a near-impossible challenge for scientists whose hands are full trying to eradicate cancer and AIDS.
“The problem is there are about 200 viruses that cause the common cold, though only about 20 or so have been strongly linked with viral cardiomyopathy,” Lome said. “That’s the whole problem with curing the common cold: We could probably spend billions of dollars and knock out one of those 200 and have 199 left.”
As if pinpointing the heart-threatening bugs weren’t challenging enough, doctors aren’t altogether sure how many people are at risk.
Doctors estimate that 1 percent to 3 percent of the population is at risk of developing a viral cardiomyopathy. Firm numbers are hard to come by, however, because most people don’t know they have viral cardiomyopathy unless it manifests life-threatening symptoms — and a good many will recover without ever knowing that bugs invaded their hearts.
“Fortunately, at least a third if not more people who develop a viral cardiomyopathy completely recover on their own without medical therapy, which is great,” Lome said. “But there is a good percentage — estimates are around a third of people — their heart will remain permanently weakened.”
Nixon was among the unlucky remainder. He initially shrugged off his ailment as a bad respiratory bug and later found he had a less-than-common heart ailment.
Nixon’s conclusion was not unreasonable. Lome readily allowed that people suffering from scratchy throats, runny noses and coughing can reasonably assume they’ve caught a cold — and not non-ischemic cardiomyopathy.
The bugaboo to watch for is shortness of breath, particularly if the patient had been in good shape. Other symptoms include fluid retention: If the limbs or feet swell, it could be a warning sign the heart is too weak to expel fluids that would otherwise be urinated.
Nixon recalled that he had an alarming lack of energy.
“No matter how much sleep I got, it wouldn’t go away,” he said. “Each day simple things were getting harder to do. It got to the point where I had a hard time walking from my kitchen to the living room, which is maybe 15 feet.”
Doctors treated him and installed a pacemaker, which has him steadily returning to good health. Indeed, Lome said doctors still are learning about the causes of idiopathic cardiomyopathy but have made great leaps in treating it with medicine and medical implements.
And while immuno-compromised patients (those with HIV, for example) need to be extra-vigilant with cold and flu viruses, Lome noted that viral cardiomyopathy remains “relatively rare.”
“The common cold is common; that’s why they call it that,” Lome said. “It’s so common yet we don’t hear of people developing heart failure because of it. That’s the reason not to worry.
“But even though it’s rare, millions of people get infected with these viruses every year in the United States. So even if it’s a small percentage of people, it still adds up to a good number.”
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