Advanced cardiac imaging: unlocking mysteries of the heart
By Vikas Veeranna, MD
When it happens, it’s often front-page news: a high school athlete, a rising national sports star or another seemingly healthy person suddenly collapses and dies, saddening and mystifying everyone. The culprit, almost always, is a previously undetected heart condition, often genetic, that was a time bomb waiting to go off.
All of those victims suffered from a specific form of a broad range of diseases of the heart muscle collectively called cardiomyopathy. Though the causes often remain a mystery and the victims may have no warning symptoms, recent advances in cardiac imaging, namely MRIs and PET scans, are making it increasingly possible for doctors to detect, diagnose, differentiate and treat these diseases before it’s too late.
Much of the attention to these sudden cardiac deaths over the past few decades has been around the shocking loss of young, thriving athletes, including nationally known stars like basketball players Reggie Lewis and Peter Maravich and U.S. Olympic volleyball player Flo Hyman. But not all victims are athletes. Many are just average young people, usually in their early teens to late 20s, who suddenly die from an undetected heart condition, sometimes in their sleep.
To understand the risks and responses better, let’s take a closer look at two of the many forms of cardiomyopathy typically affecting younger people:
Hypertrophic Cardiomyopathy (HCM) is the most common genetic disease of the heart. The walls of the heart muscle become thickened and stiff, obstructing blood flow and disrupting the heart's electrical system. HCM is the most prevalent cause of heart-related sudden death in people under 30. It's the most common identifiable cause of sudden death in athletes. Historically, HCM often has gone undetected. But thanks to recent advances in cardio-diagnostic tools like magnetic resonance imaging (MRI), we are increasingly able to pinpoint this disease.
The strongest risk factor for HCM is a family history of the disease. Absent that, a patient with heart murmur, an unexplained fainting episode, an irregular EKG or other suspicious symptoms should be considered for further diagnosis, ultimately including an MRI of the heart. If a patient is found to have HCM and deemed high risk for sudden death, they usually get a defibrillator implant which delivers an electrical current to the heart if needed to get them out of fatal heart rhythms. They also are prescribed specific medications or may need procedures to relieve obstruction to blood flow. With treatment, HCM patients can expect a normal life span with reasonable physical activity, but must limit or completely give up sports involving sudden-burst exertion.
Infiltrative Cardiomyopathy includes a group of heart disorders in which the ventricle walls of the heart become stiff due to buildup of abnormal substances within the heart muscle. These conditions can be inherited or acquired. Cardiac sarcoidosis is one such condition, usually striking between ages 20 to 40’s. It may occur when heart muscle is gradually infiltrated by microscopic clumps of inflammatory cells. It can have many of the same symptoms as heart failure, such as shortness of breath, abnormal rhythms and fluid buildup, but can often be fatal.
Diagnosis is often challenging and needs specialized testing. That can include cardiac MRIs, which may show patches of scarring in the heart muscle, and PET scans, using a special dye that “lights up” areas of active inflammation. These tests are known to pick up even the earliest signs of the disease and also help monitor it during treatment. Treatments include steroids and other heart medications, the insertion of pacemaker and defibrillator and, in extreme cases, heart transplant.
We continue to seek new and better ways to detect and treat these serious, sometimes silent heart diseases. Advanced cardiac imaging has helped us take one step closer to unlocking these mysteries sooner.
Vikas Veeranna, MD, is a cardiologist specializing in advanced cardiac imaging at Berkshire Medical Center.