Antiarrhythmic medications  slow down rapid heartbeats  and regulate irregular or premature heartbeats. Generally, these drugs work by block- ing chemical reactions that promote  electrical conduction.  They act to either suppress abnormal electrical impulses or slow down transmission of impulses as they are conducted through  heart tissue. As a result, your heart beats more rhythmically and you experience fewer symptoms.

You may be given these medications  intravenously  during an emergency situation, or they may be prescribed for you to take orally for an inde?nite  period.  Certain  antiarrhythmics, such as amiodarone,  cause side effects such as increased sensitivity to sunlight. This drug may also affect your vision, the thyroid, or the lungs. Many people are surprised to learn that an antiarrhythmic drug can in fact cause an arrhythmia or make an existing one more frequent or more severe.

You and your doctor  will need to carefully consider  the balance of bene?ts and risks of medication. Your doctor will also do thorough test- ing and monitoring, either with Holter monitoring, electrophysiologic studies, or both, to determine what drug works best for you. The electrophysiologic  testing  indicates  how well a medication  is controlling your symptoms, exactly how it alters your heart’s rhythm, and how well it protects your heart from an arrhythmia induced during the study.

Apart  from  these  antiarrhythmics, medications  such  as calcium channel blockers  or beta-blockers   may be prescribed.

If you have atrial ?brillation,  which can make you more susceptible to blood clots, you will probably  also take an anticoagulant or an antiplatelet  medication  . As with all medica- tions, drug interactions  with antiarrhythmics are always a concern;  be sure to let your doctor  know about other  medications  you are taking, including over-the-counter drugs and herbal remedies.