What is Cardioversion? Purpose, Levels/Procedure & Results

Cardioversion is a medical procedure that helps restore your heart's normal rhythm when it's beating irregularly or too fast. Think of it as a gentle "reset" for your heart, similar to restarting a computer that's running slowly. This safe, well-established treatment can quickly bring relief if you're experiencing certain heart rhythm problems.

Your heart has its own electrical system that controls how it beats. Sometimes this system gets disrupted, causing your heart to beat in an irregular pattern called an arrhythmia. Cardioversion works by delivering a controlled electrical shock or using medications to help your heart remember its proper rhythm again.

What is cardioversion?

Cardioversion is a procedure that corrects abnormal heart rhythms by restoring your heart's natural electrical pattern. There are two main types: electrical cardioversion, which uses a brief electrical shock, and chemical cardioversion, which uses medications.

During electrical cardioversion, doctors place special paddles or patches on your chest while you're under light sedation. The device then sends a quick, controlled electrical pulse to your heart. This pulse interrupts the chaotic electrical signals causing your irregular heartbeat and allows your heart's natural pacemaker to take control again.

Chemical cardioversion works differently but achieves the same goal. Your doctor gives you medications through an IV or by mouth that help regulate your heart's electrical activity. This approach takes longer than electrical cardioversion but can be just as effective for certain types of rhythm problems.

Why is cardioversion done?

Cardioversion is recommended when you have certain heart rhythm disorders that aren't responding to other treatments or are causing concerning symptoms. The most common reason is atrial fibrillation, where the upper chambers of your heart beat chaotically instead of in a coordinated way.

You might need cardioversion if you're experiencing symptoms like chest pain, shortness of breath, dizziness, or extreme fatigue due to your irregular heartbeat. These symptoms happen because your heart isn't pumping blood effectively when it beats irregularly.

Your doctor may also recommend cardioversion for other rhythm problems like atrial flutter, where your heart beats too fast in a regular pattern, or certain types of ventricular tachycardia. Sometimes cardioversion is done as a planned procedure, while other times it's needed urgently if your symptoms are severe.

The procedure is particularly helpful for people whose heart rhythm problems are relatively new or happen in episodes. If you've had irregular rhythms for a long time, cardioversion might still work, but your doctor will need to evaluate your specific situation carefully.

What is the procedure for cardioversion?

The cardioversion procedure typically takes place in a hospital or outpatient clinic where you'll be closely monitored throughout the process. You'll be connected to machines that track your heart rhythm, blood pressure, and oxygen levels before, during, and after the procedure.

For electrical cardioversion, you'll receive medication through an IV to help you relax and sleep lightly during the procedure. Once you're comfortable, your doctor will place electrode pads on your chest and sometimes on your back. The cardioversion machine will then deliver one or more brief electrical shocks to reset your heart rhythm.

The actual shock lasts only a fraction of a second, and you won't feel it because of the sedation. Your medical team will monitor your heart rhythm immediately after each shock to see if your normal rhythm has returned. If the first shock doesn't work, your doctor might try again with a slightly higher energy level.

Chemical cardioversion follows a different timeline. You'll receive medications through an IV, and your medical team will monitor you for several hours as the drugs work to restore your normal rhythm. This process is gentler but takes longer, sometimes several hours to see full results.

How to prepare for your cardioversion?

Preparing for cardioversion involves several important steps to ensure the procedure goes smoothly and safely. Your doctor will give you specific instructions based on your individual situation, but there are some common preparations you'll need to follow.

You'll typically need to stop eating and drinking for at least 6-8 hours before the procedure, especially if you're having electrical cardioversion with sedation. This precaution helps prevent complications if you need to vomit while sedated.

Your doctor might adjust your medications before the procedure. If you take blood thinners, you'll usually need to continue them or start them several weeks before cardioversion to reduce your risk of blood clots. Never stop or change your medications without talking to your healthcare team first.

You should arrange for someone to drive you home after the procedure, as the sedation can make you drowsy for several hours. It's also helpful to wear comfortable, loose-fitting clothing and remove any jewelry, especially necklaces or earrings that might interfere with the electrode placement.

Your doctor may order additional tests before the procedure, such as an echocardiogram to check your heart's structure or blood work to ensure your body is ready for the treatment. These tests help your medical team plan the safest approach for your specific situation.

How to read your cardioversion results?

Cardioversion results are typically measured by whether your heart rhythm returns to normal and stays that way. Success is usually defined as achieving and maintaining a normal heart rhythm called sinus rhythm for at least 24 hours after the procedure.

Immediately after cardioversion, your medical team will monitor your heart rhythm on an electrocardiogram (EKG) to see if the procedure worked. A successful cardioversion will show a regular heart rhythm with a normal rate, typically between 60-100 beats per minute.

Your doctor will also assess how you feel after the procedure. Many people notice an immediate improvement in symptoms like shortness of breath, chest discomfort, or fatigue once their heart rhythm normalizes. However, some people feel tired for a day or two as their body adjusts to the rhythm change.

Long-term success is measured over weeks and months. Your doctor will schedule follow-up appointments to monitor your heart rhythm and may recommend wearing a heart monitor for a period of time to track how well your heart maintains its normal rhythm.

It's important to understand that cardioversion doesn't cure the underlying condition that caused your irregular rhythm. The procedure resets your heart rhythm, but you may need ongoing treatment with medications or other therapies to prevent the rhythm problem from returning.

How to maintain your heart rhythm after cardioversion?

Maintaining your normal heart rhythm after cardioversion often requires ongoing care and lifestyle adjustments. Your doctor will likely prescribe medications to help keep your heart in its normal rhythm and prevent future episodes of irregular heartbeat.

Taking your medications exactly as prescribed is crucial for long-term success. These might include antiarrhythmic drugs to maintain your heart rhythm, blood thinners to prevent clots, and medications to control your heart rate. Each medication plays a specific role in keeping your heart healthy.

Lifestyle changes can significantly improve your chances of staying in normal rhythm. Regular exercise, as approved by your doctor, helps strengthen your heart and improve your overall cardiovascular health. Managing stress through relaxation techniques, adequate sleep, and healthy coping strategies also supports heart rhythm stability.

Avoiding triggers that might cause your irregular rhythm to return is equally important. Common triggers include excessive alcohol consumption, caffeine, certain medications, and significant stress. Your doctor can help you identify your specific triggers and develop strategies to avoid them.

Regular follow-up appointments allow your healthcare team to monitor your progress and adjust your treatment plan as needed. Don't hesitate to contact your doctor if you notice symptoms returning or if you have concerns about your heart rhythm.

What is the best outcome for cardioversion?

The best outcome for cardioversion is achieving and maintaining a normal heart rhythm that allows you to feel well and participate in your daily activities without symptoms. Success rates vary depending on the type of rhythm problem you have and how long you've had it.

For atrial fibrillation, cardioversion is immediately successful in about 90% of cases, meaning your heart rhythm returns to normal right after the procedure. However, maintaining that normal rhythm long-term is more challenging, with about 50-60% of people staying in normal rhythm for one year.

The best outcomes typically occur in people who have had irregular rhythms for a shorter time, have smaller heart chambers, and don't have significant underlying heart disease. People who maintain healthy lifestyles and take their medications consistently also tend to have better long-term results.

Even if your rhythm eventually becomes irregular again, cardioversion can often be repeated successfully. Many people undergo the procedure multiple times over the years as part of their ongoing heart rhythm management.

What are the risk factors for cardioversion failure?

Several factors can increase the likelihood that cardioversion won't work or that your irregular rhythm will return soon after the procedure. Understanding these risk factors helps you and your doctor make informed decisions about your treatment.

The length of time you've had irregular rhythm is one of the most important factors. If you've been in atrial fibrillation for more than a year, cardioversion is less likely to be successful long-term. This happens because your heart muscle changes over time when it beats irregularly.

The size of your heart chambers also affects success rates. People with enlarged atria (the upper chambers of the heart) are more likely to have their irregular rhythm return after cardioversion. This enlargement often develops over time when the heart works harder due to irregular beating.

Underlying heart conditions can make cardioversion less effective. These include heart valve problems, coronary artery disease, heart failure, or cardiomyopathy. Your doctor will evaluate these conditions and may recommend treating them before or alongside cardioversion.

Other medical conditions that can affect cardioversion success include thyroid disorders, sleep apnea, high blood pressure, and obesity. Managing these conditions well before cardioversion can improve your chances of success.

Age itself isn't necessarily a barrier to cardioversion, but older adults may have more underlying health conditions that affect the procedure's success. Your doctor will consider your overall health rather than just your age when recommending treatment.

Is it better to have electrical or chemical cardioversion?

Both electrical and chemical cardioversion can be effective, but the best choice depends on your specific situation, the type of rhythm problem you have, and your overall health. Your doctor will recommend the approach that's most likely to work safely for you.

Electrical cardioversion is generally more effective and works faster than chemical cardioversion. It successfully restores normal rhythm in about 90% of people with atrial fibrillation and takes only minutes to complete. This makes it a good choice when you need quick results or when medications haven't worked.

Chemical cardioversion may be preferred if you have certain health conditions that make sedation risky, or if your irregular rhythm is relatively new and might respond well to medications. It's also sometimes used as a first approach in younger, healthier people with recent-onset atrial fibrillation.

The recovery process differs between the two approaches. After electrical cardioversion, you'll need time to recover from the sedation, but the procedure itself is over quickly. Chemical cardioversion takes longer but doesn't require sedation, so you can go home sooner once your rhythm is stable.

Your doctor will consider factors like your age, other health conditions, medications you take, and how long you've had irregular rhythm when recommending which type of cardioversion is best for you.

What are the possible complications of cardioversion?

Cardioversion is generally a safe procedure, but like any medical treatment, it does carry some risks. Understanding these potential complications helps you make an informed decision about your treatment and know what to watch for afterward.

The most serious but rare complication is stroke, which can occur if a blood clot forms in your heart and travels to your brain. This risk is why your doctor will typically prescribe blood thinners before and after the procedure. The risk of stroke is very low when proper precautions are taken.

Skin irritation or burns at the electrode sites can occur with electrical cardioversion, but these are usually minor and heal quickly. Your healthcare team uses special gels and techniques to minimize this risk. Some people experience temporary redness or mild soreness where the electrodes were placed.

Temporary rhythm disturbances can happen immediately after cardioversion as your heart adjusts to its new rhythm. These usually resolve on their own within a few hours, but your medical team will monitor you closely to ensure your heart rhythm remains stable.

Some people experience brief drops in blood pressure during the procedure, which is why you'll be monitored continuously. Your healthcare team is prepared to treat this if it occurs, and it rarely causes lasting problems.

Memory problems or confusion can occur after electrical cardioversion due to the sedation, but these effects are temporary and typically resolve within a few hours. Having someone available to drive you home and stay with you is important for this reason.

Rarely, cardioversion might trigger more serious rhythm problems, but your medical team is equipped to handle these situations immediately. The procedure is performed in a controlled environment with emergency equipment readily available.

When should I see a doctor after cardioversion?

You should contact your doctor immediately if you experience chest pain, severe shortness of breath, dizziness, or fainting after cardioversion. These symptoms could indicate that your heart rhythm has become irregular again or that other complications have developed.

Call your healthcare provider if you notice your heart beating irregularly or if you feel like your heart is racing, skipping beats, or fluttering. These sensations might mean your irregular rhythm has returned, and early intervention can often help restore normal rhythm more easily.

Seek immediate medical attention if you develop signs of a stroke, including sudden weakness on one side of your body, trouble speaking, sudden severe headache, or vision changes. While stroke after cardioversion is rare, it's important to recognize these warning signs.

You should also contact your doctor if you have unusual swelling in your legs or ankles, as this could indicate heart failure or other complications. Similarly, if you feel much more tired than usual or have trouble breathing during normal activities, these could be signs that your heart isn't working as well as it should.

Don't hesitate to reach out if you have concerns about your medications or if you're experiencing side effects that worry you. Your healthcare team wants to ensure you're comfortable and that your treatment is working effectively.

Schedule your follow-up appointments as recommended, even if you feel well. Regular monitoring helps catch any problems early and allows your doctor to adjust your treatment plan if needed.