Cardioversion refers to the restoring of the heart’s normal rhythm from an abnormal rhythm. Most elective cardioversions are performed to treat atrial fibrillation, a benign heart rhythm disturbance originating in the upper chambers of the heart.
Normally, each heartbeat starts in the upper right chamber (right atrium) of the heart in a region containing specialised pacemaker cells. Each time these cells fire, usually 1 to 2 times per second, they send an organised electrical signal through the heart that result in a coordinated, rhythmic heartbeat.
In patients with atrial fibrillation, instead of the normal organised electrical activity, the atria fibrillate, or quiver, because of chaotic electrical wavefronts that circulate throughout both atria. This can result in less efficient blood pumping and an irregular or fast heartbeat.
Some patients have no symptoms, whereas others may feel rapid heart action, shortness of breath, dizziness or fatigue and a general feeling of being unwell. Depending on your specific medical history and symptoms, your cardiologist may recommend a cardioversion to return your heart to a normal rhythm.
The test will be performed as an inpatient and therefore will require admission into hospital. You will be required to fast for at least 6 hours prior to the procedure.
Take your regular medications the morning of the procedure, unless your doctor advises you otherwise. Your medications should only be taken with a little bit of water. If you are diabetic, you should discuss your insulin or other diabetic medication with your doctor. Bring a list of your medications with you to hospital.
Do not apply any lotions or ointments to your chest as it may interfere with the adhesiveness of the shocking pads.
A cardiologist will be performing the cardioversion, assisted by an anaesthetist and nursing staff. An IV line (drip) will be placed in your arm and medications given to put you into a light sleep. Your throat will also be sprayed with an anaesthetic that will numb your gag reflex, this is to allow your Cardiologist also perform a Transoesophageal Echocardiogram before your Cardioversion if required. Your electrocardiogram, oxygen saturation and other vital signs will be monitored during and after the procedure.
A Cardioversion is where a synchronised electrical current or shock is delivered through the chest wall to the heart through special electrodes or paddles that are applied to the skin of the right upper chest and left lower chest. The purpose of the cardioversion is to interrupt the abnormal electrical circuits in the heart and to restore a normal heartbeat. The delivered shock causes all the heart cells to contract simultaneously, thereby interrupting and terminating the abnormal electrical rhythm without damaging the heart. The heart’s electrical system then restores a normal heartbeat. You will be asleep for the entire procedure.
You will remain in hospital for approximately 3 hours after the cardioversion and will not be allowed to eat or drink for an hour or two, or until your gag reflex returns.
For several hours after the test you may feel sleepy and have a dry throat. As a result of the nature of some of the medications you may not be able to remember much of the test. You will need to have someone to take you home after the procedure as you are unable to drive for 12 hours post procedure.
The Cardiologist will send a report electronically and via post or fax to your referring doctor. You will need to contact your referring doctor to discuss your results and any follow up that maybe required, including medications and appointments.