Like a snake, the heart disease known as ARVD, or arrhythmogenic right ventricular dysplasia, can silently sneak up on its victims, strike violently and kill. Those with the condition -- typically athletic 20-to-40 year-olds -- may feel palpitations in their chest or fainting sensations and see their doctor, but for many, an out-of-control, wildly racing heart is their first symptom -- and their last.
"The heart rapidly speeds up and they die, a significant portion of them before they've ever been diagnosed," says cardiologist Hugh Calkins, M.D. 
| Using high-speed MRI to freeze the motion of the heart, Hugh Calkins is able to obtain clear images of fatty and scarred tissue in the right ventricle. |
ARVD is a result of abnormal cardiac tissue. In a normal heart, the healthy smooth muscles lining the right ventricle enhance conduction of the electrical current that produces a heart beat. But in ARVD patients the tissue on the wall of the right ventricle is fatty and scarred, causing the current to short circuit and triggering the life-threatening arrhythmias. What's especially troubling about this condition, Calkins says, is that it's treatable. An implanted defibrillator that shocks the heart back to a regular rhythm can correct the deadly arrhythmia when it occurs and give a patient with ARVD a full life. The problem is that the condition has been almost impossible to diagnose until it's too late. Conventional imaging techniques simply haven't been able to detect the subtle strands of scarred and fatty tissue that signify the disease in the tiny, shaking wall of the right ventricle. "We are looking at a very small space, about 1-to-2 millimeters wide, that's moving every 15 milliseconds with breathing and the beat of the heart," explains radiologist David Bluemke, M.D. "All this movement blurs out the fat signals in conventional MRI." Now, however, thanks to new, high-speed MRI scanners and careful testing, Bluemke and Calkins are improving the outlook for ARVD patients. MRI has become much more central to diagnosis. Using the new technology, the two physicians have been able to freeze the motion of the heart and capture crisp, detailed images. "It's made a night and day difference in detection," Bluemke says. To confirm the diagnosis, the images are correlated with other test results, like electrocardiography records of the electrical activity of the heart. Today, Calkins and Bluemke know for certain if a patient with suspicious palpitations has ARVD and warn the person immediately of the insidiousness of the condition. "Getting the right diagnosis for these patients and doing it quickly is key," Bluemke says. "People have died waiting for their diagnosis."
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