The Importance of QT/QTc Prolongation: A Case Study
- PDF / 2,330,357 Bytes
- 2 Pages / 648 x 864 pts Page_size
- 43 Downloads / 202 Views
I N T E R V A L P R O L O N G A T I O N 38s
The Importance of QT/QTc Prolongation: A Case Study
Morilyn A. Agin, PhD Pfizer Global Research and Development, New London, Connecticut
Corrrspondrncr Addrrss Marilyn A. Agin, Pfizer Global Research and Development, 2800 Plymouth Road, Ann Arbor. MI 48105 (email: Marilyn.Agin@pfizmcom).
You never know when something you learned at work can save your life. I was fortunate to be able to attend a QT interval workshop at my office. During the class, I learned a lot about the electrical function of the heart as well as about medicines that can cause QT prolongation, a change in the way the electrical signal moves through the heart. QT prolongation is important because it can sometimes lead to a potentially fatal heart arrhythmia know as torsades de pointes. Torsades is very rare. It never occurred to me during the workshop that I might be one of those rare cases. I had just begun taking an antiarrhythmic agent used for the treatment of atrial tachycardia, a rapid heartbeat originating in the upper part of the heart. In the workshop, I had learned that a prolonged QT interval could be one of the risk factors for torsades. As a safety precaution, my physician carefully monitored my heart rate during the first few days after I began taking the new medication. A few hours after taking my fifth morning dose, I suddenly felt the blood leave my head and my knees go weak. I thought I was going to faint. After sitting for a few minutes to calm down, I began to wonder if I was having a
bad reaction to the antiarrhythmic medication. I knew from attending the QT interval workshop that this drug was on the list of drugs associated with QT prolongation and torsades. I had also learned that fainting was one of several symptoms associated with this heart arrhythmia. Based on these two pieces of information, I decided to go to the hospital rather than back to bed to "sleep off" the side effect. I really believe that this decision saved my life. On arrival at the hospital, I told the admissions nurse that I was being treated with an antiarrhythmic agent and was having a bad side effect-an unstable and rapid heart rhythm. I was whisked back to the special cardiac unit in the emergency room. After hooking me up to a variety of electrocardiogram machines, the physicians soon confirmed what 1 had suspected potentially fatal torsades de pointes was indeed the problem. The electrocardiogram for torsades is so distinctive that I recognized it from the PowerPoint slide shown during the workshop. Fortunately, I remembered that the instructor had discussed the administration of magnesium sulfate as a primary treatment for torsades de pointes. So, I began telling the emergency room
Drug InformatimJoumd, Vd. 39. pp. 38.5-386,2005 0092-8615/2005 Information AFsociation. Inc. Ph'nted in the USA. AII rightF m d . cowright 0 2005
386
QT/QTc
INTERVAL PROLONGATION
medical staff that they needed to give me magnesium sulfate to stop the arrhythmia. I would like to tell you that they immediately believe
Data Loading...
