Several years before I met my wife, when she was in her early twenties, she was diagnosed with cardiomyopathy, also called heart failure or congestive heart failure. The cause was likely related to some sort of viral infection, but there is no way to be sure. What we do know is that her heart muscle is weak and unable to pump blood the way it should.
Over the course of the years since her diagnosis, her heart has, predictably, gotten weaker. Not too long ago, when her heart’s ejection fraction (the percentage of blood her heart pumps out with each beat) dropped below 30 percent, she was strongly advised to have a defibrillator implanted in her chest, which was done. Its purpose is to monitor her heart rhythm and, if it goes haywire, shock it into a normal rhythm. In my wife’s case, her history and her state of heart health argued that she was a prime candidate for sudden cardiac arrest. Even had we not had insurance, that was a procedure that had to be done.
The other day, each of us received a mailer from Baylor Heart Hospital in Plano, inviting us to attend a seminar that evening on preventing sudden cardiac arrest (SCA), one of the dangers facing people with cardiomyopathy. Although my wife already had the defibrillator, she wanted to go to the seminar to see if there might be any new ideas presented about preventing SCA.
It became apparent, early on, that the seminar really was about defibrillators. However, the session was extremely informative. I’m sure we had received the same information from my wife’s cardiologist before her procedure, but when you’re receiving the news for the first time about the need for a lifesaving device, I think you tend to be in shock and it doesn’t all sink it. So it was valuable to go to the session.
I had never completely understood the difference between a heart attack and SCA. It was explained to me as follows: a heart attack is essentially a “plumbing problem” which results from restricted blood flow into the heart, due to clogged arteries and the like, whereas SCA results from an electrical problem that causes the heart’s rhythm to go wildly out of control and to suddenly stop. Most victims of heart attacks survive; 95% of victims of SCA do not. SCA claims about 450,000 lives each year, more than stroke, lung cancer, breast cancer, and AIDS combined. It is the single largest killer in the U.S. Unfortunately, SCA is not well known; there is no “poster child” for SCA.
While the likelihood of SCA in those at risk is less than 5% per year, the likelihood of SCA in people at high risk (people whose ejection fraction is 35% and below) is cumulative. So a person who reaches that risk level at age 50 is very likely to have an event by the time they are 70 or 80. There are no significant warning signs for SCA; it strikes suddenly. If there are any signs at all, they may be that the person feels lightheaded and has heart palpitations. But those symptoms are rare and sudden. Generally, with SCA, the person suddenly loses consciousness and quickly becomes motionless. The person does not breathe, move, or cough. There is no pulse. If a victim of SCA does not receive appropriate treatment (restarting the heart and normalizing the rhythm) within six minutes, he or she will die. That’s the reason for the implantation of a defibrillator. The vast majority (99%) of people with a defibrillator who experience SCA survive. The vast majority (95%) of people without a defibrillator who experience SCA do not. Consider this: the average response time to a call to 911 is 6 to 12 minutes; the SCA victim has only six minutes before he or she dies. Even the fastest response may not be fast enough.
The key message from the doctor who delivered the presentation (I was highly, highly impressed with her: Hafiza Khan, M.D., FACC) was for heart patients, who she advised to be their own advocates. She suggested patients ask their doctors what their ejection fraction is, question whether it has deteriorated since the last visit, and inquire about the need for an implanted defibrillator.
I had double heart bypass several years ago, which was done to prevent me from having a heart attack. Now, I think I’ll ask my cardiologist, next time I visit, what my ejection fraction is; I’d like confirmation that it’s where it ought to be.