(February 17, 2009 - Insidermedicine) In this video, Dr. Richard Stein, MD, FACC, discusses what he would do if he had an irregular heartbeat and had been diagnosed with long QT syndrome. Dr. Stein is a Professor of Medicine in the Charney Division of Cardiology at NYU's Langone Medical Center.
At the American Heart Association's scientific sessions in New Orleans, we caught up with Dr. Richard Stein, who was a professor of medicine in the Charney Division of Cardiology, and director of the Urban Community Cardiology program, at New York University's Langone Center.
What is long QT syndrome
Dr. Stein: It is a reading on a electrocardiogram, and there is a QRS wave, which is the contraction of your heart; and then there is the T wave, which is the repolerization of your heart, electrically getting ready to contract again. From the beginning of the Q wave to the end of the T wave, on the electrocardiogram, is your QT interval. Now it normally changes with heart rate, so we correct it, essentially, by dividing it by the square root of the millisecond or time between each heart beat, essentially bringing everyone down to a heart rate of 60, with a one second time delay between each beat. And normally speaking, most of us should walk around with just a little bit of under a second, about 450 milliseconds, or 450 thousandth of a second. When you get up to 460-480 we get very concerned. When you get over 480, it becomes clearly a long QT syndrome, and then we are concerned that you are at risk of dying suddenly. This is in many instances an abnormal gene that carry, so one of the things that will make you more concerned is if you knew of someone in your mother or father's or your family, who had died suddenly. And in that case, you should actually seek the attention, not even of a general cardiologist, but the cardiologist who specializes in cardiac arrhythmias, a cardiac electrophysiologist, or EPS trained cardiologist.
Is long QT syndrome heritable?
Dr. Stein: At the end of the day, if you've had a first order relative that has died suddenly, if you have yourself experienced episodes of fainting or syncope, sudden dropping, which would be this arrythmia that would self terminate, it is called a tricia tachycardia, and one of the characteristics of people with these genetic abnormalities is they have so called "NSVT", non-sustained ventricular tricia tachycardia. So if your heart goes into a very rapid beat but it only lasts 10 or 15 seconds, you'll drop, you'll faint, but it will be back to normal and profusing your brain and you'll wake up again. So if you have these sudden episodes of syncope or loss of consciousness, if you have a first order relative that has died suddenly, and you have a long QT; the odds are very significant that you have inherited this problem.
What test are used to diagnose long QT syndrome?
Dr. Stein: It's the simple electrocardiogram that a physician or nurse can perform in the office. In today's world, two thirds of those are actually interpreted by a computer, and they are done accurately. And they will measure and correct this QT interval from the beginning of one wave to the end of another, and if that is long, getting up to and exceeding half of a second, then you have long QT syndrome.
What are the implications of long QT syndrome?
Dr. Stein: Well, the implications are that you have a risk of dying suddenly. If you have some of the types that risk can be more common during the extremes of exercise or stress, because your own norepinephrine or adrenaline in your blood actually can promote the same process that the QT syndrome is promoting. In some instances, it can occur during sleep, and in some instances it seems to be just a random event. You could be sitting or talking and suddenly it happens. It's a not uncommon and increasingly appreciated cause of otherwise healthy people, either playing sports or right after their sport events, dying suddenly.
How is long QT syndrome managed?
Dr. Stein: It is managed really for the patients who have either QT One or Two, we can reduce but not obliterate your chance of dying suddenly by giving you a drug called a beta blocker. If you have any long QT syndrome, there is series of drugs and drug combinations which can make it a lot worse, and widen the QT, and we think increase your risk of sudden death. Combinations of antibiotics, very common ones like Aritha Myson, can bind with some decongestants, combined with some antifungal medications, are all drugs that can increase your QT further, and increase your risk. So, what I tell my patients to do after they have gotten their list, and it is a constantly changing list, go on Google and type in "Long QT Drugs", and there is a website, Long QT Drugs, and you see if the drug that your doctor wants you to take or you are currently taking is on that list, and if you have a long QT syndrome or a borderline long QT syndrome, then you should really stop the drug and discuss it with the doctor. Because in some of these genetic abnormalities that make up the QT syndrome, it is necessary for us to actually put in an automatic defibrillator. If we think your risk of having your heart fibrillate and you die is significant enough, then this device which would automatically monitor your heart then defibrillate you. This is sort of a micro version of what you see on television when they put the paddles on the guy and, the beep suddenly starts to look regular on the monitor. These are smaller shocks but they are delivered directly to the inside wall of the heart, and they will have the same effect, they will basically convert you back to normal sinuous rhythm and save your life.
Are there any surgical procedures for long QT syndrome?
Dr. Stein: There is not surgical for this, we are talking about channels that are so thin that you would need an electron microscope to visualize them. Single ions that we conceptually know move across those channels but we have no way of seeing or touching. And, the only mechanism we have is really implanting a device, although, so that is a surgical event, where the electrophysiologist will put something about the size of half your fist and much flatter, under your wall of your muscle of your chest and, putting the electrodes and leads into your heart, to monitor your heart beat.
If I had an irregular heartbeat and was diagnosed with prolonged QT syndrome...
Dr. Stein: If I had a episode of sudden fainting or two, or a relative of mine had died suddenly without any medical clear understanding, then I would get an electrocardiogram, an EKG done, and if the doctor or nurse reading this said your QT interval is long, I would then, obviously, go see an electrophysiologist to have this evalutated. I would expect my bloods to be sent off for the genetic tests that could confirm that I did indeed have a Long QT because of a genetic abnormality. I would understand that I would check periodicly, especially if I was going on a new medication, that the medication wouldn't make this situation worse. I would expect in most instances, that I would be put on a medication if I had what we call Long QT One, a beta blocker, and that I would very likely need an implanted defibrillator. This is really right on the edge of cusp of our knowledge and yearly there are big changes made in this field, mostly by our level of knowledge and understanding getting greater. So it's important that you both: see and electrophysiologist if you are uncomfortable with the idea of getting a defibrillator, which I would not think anyone wouldn't be, and get a second opinion unless you've arrived at this person with already having done that. Then really ask that person to have you talk to a few of their patients that have had these in, and understand what the impact has been on their lives and how they have managed it. Because it is now a managable phenomena to keep you from dying early of this disease.