What to know about variable heart rhythms and AFib
An Ohio State cardiac electrophysiologist shares what to know about heart rhythms and AFib.
Antiarrhythmic medications are used to treat arrhythmias. An arrhythmia is an abnormal heartbeat that causes your heart to beat too quickly or too slowly. Types of fast arrhythmias include atrial fibrillation, atrial flutter, supraventricular tachycardia, ventricular tachycardia and premature heartbeats. Antiarrhythmic medications are used only to treat rapid heart rhythms. (Slow arrhythmias are called bradycardia and are treated with a pacemaker.)
Antiarrhythmic medications include several types of medications that are designed to help restore and maintain the normal rhythm of the heart. There are four main types of these medications:
Sodium channel blockers – These medications block the sodium channel of the heart muscle cells which decreases the speed of electrical conduction. These medications include procainamide (Procan SR, Procanbid, Pronestyl), quinidine (Quinaglute, Quinidex), disopyramide (Norpace), flecainide (Tambocor) and propafenone (Rythmol and Rythmol SR). Each of these medications has a unique set of features and side effects.
Beta blockers – The primary goal of beta blockers is to slow down your heart rate. This will reduce your heart rate during an episode of your abnormally fast heart rhythm. This type of medication is primarily used to control the heart rate during an arrhythmic episode and may also reduce the number of episodes that you experience.
Potassium channel blockers – These medications block the potassium channel in the heart muscle cell and help prevent arrhythmias by lengthening the time of the electrical impulse between heartbeats. These medications include sotalol (Betapace), dofetilide (Tikosyn) and ibutilide (Corvert, which can be administered only intravenously), amiodarone (Pacerone, Cordarone) and Dronedarone (Multaq). Each of these medications has unique side effects.
Calcium channel blockers – These medications are designed to slow the heart rate when experiencing an abnormal heart rhythm. They are also often used to treat high blood pressure. Examples of calcium channel blockers include diltiazem (Cardizem, Cartia) and verapamil (Tiazac, Calan).
The goal of therapy with an antiarrhythmic medication is to prevent recurrences of an abnormal, fast arrhythmia. Some patients who take an antiarrhythmic medication will unfortunately still experience some episodes of the heart rhythm problem. Therefore, the goal with these patients is to significantly reduce the frequency and duration of an abnormal heart rhythm problem while avoiding side effects of the medication.
Selection of an antiarrhythmic medication
To determine the antiarrhythmic medication that will be best for your condition, your physician will consider the health of your heart (as indicated by your ejection fraction or pumping function of the heart muscle, measured through an echocardiogram), your type of heart rhythm problem and any other medical problems you may be experiencing, such as kidney, liver or lung disease. You may also be enrolled in Ohio State’s Antiarrhythmic Medication Clinic. This clinic is directed by pharmacists at Ohio State who specialize in the use of antiarrhythmic medications and will monitor you for side effects and interactions with other medications.
For some patients, it will be suggested that they be admitted to the hospital before starting the antiarrhythmic medication. Patients are typically admitted to Ohio State’s Arrhythmia Unit, located on the seventh floor of the Ross Heart Hospital. The staff on this floor is specially trained for the management of antiarrhythmic medication. Our physicians and pharmacists have established specific protocols for starting and monitoring antiarrhythmic medications. The main reason for being hospitalized is so your heart rhythm can be continuously monitored and assessed for any changes as a result of the new medication. Most patients experience no symptoms but changes in your heart rhythm may indicate that the dosage or type of medication should be changed.
Antiarrhythmic medications are very useful in helping to control heart rhythm problems, but they must be tailored to each individual’s specific needs and do have side effects. To minimize any side effects, several different tests are performed to monitor the safe use of this medicine even after you are discharged from the hospital. You may be monitored by a team of specialized pharmacists at our Antiarrhythmic Medication Clinic for side effects and possible interactions with other medications.
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