Electrical System of a Normal Heart
The first electrical signal comes from the heart’s own natural pacemaker, the sinoatrial node, located in the upper right heart chamber. This node sends a steady stream of electrical signals along a pathway through the heart’s upper chambers. The signals then travel to the junction – the atrioventricular node – between the upper and lower chambers and, finally, move to the lower chambers.
What is atrial fibrillation?
Atrial Fibrillation, or AFib, is a relatively common condition that causes the upper chambers of the heart (the atria) to beat rapidly and in an uncontrolled manner (fibrillation). This uncoordinated, rapid beating of the atria affects the flow of the blood through the heart, causing an irregular heartbeat and sometimes a sensation of fluttering the chest.
When you have an AFib episode, blood is not always pumped completely out of the atrium. If your blood is not flowing correctly, there is the possibility of a blood clot forming. If this blood clot does not dissolve and is pumped out of your heart, it may travel to one of the arteries supplying blood to your brain and cause a blockage leading to a stroke.
What causes atrial fibrillation?
Although AFib can be caused by a number of different factors, sometimes there is no obvious cause for the condition. Some factors that can initiate AFib include excessive alcohol intake, physical stress, medications that stimulate the heart, heart surgery, various heart problems, hyperthyroidism and lung disease. People with risk factors for heart disease, such as high blood pressure or diabetes, are also at increased risk.
What are some symptoms of AFib?
The most common symptoms experienced during an AFib episode include heart palpitations, rapid pulse, shortness of breath, weakness, fatigue, dizziness/light-headedness, fainting and chest pain. There are instances where atrial fibrillation may cause minor symptoms or even none at all. This is caused asymptomatic atrial fibrillation.
Why should I explore treatment for my AFib?
- AFib is a progressive disease that becomes more difficult to treat over time. Your episodes are likely to increase in frequency or intensity as you age, therefore early intervention is key.
- AFib is not life threatening in itself; however, it is important to treat because AFib is responsible for up to 1 in 5 stroke occurrences. It is the leading cause of stroke among people aged 65 and older.
- AFib may sometimes also lead to congestive heart failure where the heart can no longer adequately pump blood.
What are my treatment options for AFib?
- Anticoagulant Medications (blood thinners):
- Prescribed to AFib patents to prevent clotting which can reduce risk of stroke.
- Rate Control Medication:
- Prescribed to AFib patients to slow your heart rate to less than 100 beats per minute.
- Rhythm Control Medication:
- Prescribed to AFib patients to control your arrhythmia if rate control does not work. Referred to as “drug cardioversion.”
- Catheter Ablation:
Pulmonary vein isolation is an effective treatment and standard approach for patients with drug-refractory symptomatic atrial fibrillation. This is accomplished through ablation, which uses 1 of 2 energy sources and modes of application.
- Radiofrequency ablation utilizes a radiofrequency current that is applied in a point-by-point mode, heating the tissue and leading to cellular necrosis.
- Cryogenic ablation induces necrosis by pumping refrigerant (N2O) through a balloon in a single-step mode, thereby freezing the tissue.
Both methods are approved by the US Food and Drug Administration (FDA) for treatment of paroxysmal AF.
What Happens During Cryoablation?
- A doctor inserts the balloon catheter into a blood vessel, usually in the upper leg, and then threads it though the body until it reaches the heart. This narrow tube has an inflatable balloon on one end that engages the pulmonary vein. Using advanced imaging techniques, the doctor is able to guide the catheter to the heart.
- Once the balloon is at the ostium of the pulmonary vein, extreme cold energy flows through the catheter to destroy this small amount of tissue and restore a healthy heart rhythm.
What is Radiofrequency ablation (RFA)?
- Catheter ablation is a minimally invasive procedure that is performed by an electrophysiologist who uses a thin catheter to determine or map where the abnormal electrical signals that trigger AFib are originating in your heart. Guided by this map, the electrophysiologist places a catheter into your heart to pinpoint the source of the abnormal electrical signals.
- Once the source of your arrhythmia is located, a therapeutic catheter transmits radiofrequency waves, generating enough heat to produce a small scar on the targeted part of your heart tissue. This process blocks the abnormal electrical impulses that cause your heart to beat irregularly.
- Catheter ablation can reduce or even eliminate the need for medical treatment of paroxysmal AFib. It can also treat the underlying cause of your irregular heartbeat, decrease your risk of stroke and enable you to return to normal activities.
How do I prepare for the catheter ablation?
Prior to your procedure, check with our office to see what medications you are allowed to take. We may ask you to discontinue your blood thinners several days before your scheduled procedure. Also, if you have diabetes, check with the office to see if these medications need to be adjusted.
Do not eat or drink anything after midnight on the evening before your procedure. You are only allowed a sip of water with your medications – no other liquids or solids are permitted.
You will be changed into a hospital gown prior to your procedure, so you may wear comfortable clothes into the hospital. Please leave any of your valuables, including jewelry at home.
What is the process of the procedure?
Your cardiac ablation will take place in a specialized lab called the electrophysiology (EP) lab, where you will be connected to heart rhythm monitors. You will also be shaved and prepped at this time, which includes an antiseptic scrub of the groin area where the doctor is inserting catheters.
You will then be placed under general anesthesia by one of the hospital’s anesthesia providers. He or she will remain at the head of your bed for the entire procedure, so you are constantly monitored.
Once asleep, your physician will insert several catheters into the blood vessels in your groin, and these catheters will be advanced into the right atrium. A needle will then be used to advance these catheters to the left side of the atria. These catheters will find the abnormally firing cardiac tissue and deliver RF energy or ablate the areas in order to put you back in normal rhythm.
The ablation is done by creating circular scars around your pulmonary veins as they are traditionally the cause of the abnormal firing in your left atrium. With these scars in place, the firing can no longer reach your heart tissue and thus prevents atrial fibrillation from occurring. All four pulmonary veins receive this treatment. Other linear lines may also be created in patients with persistent atrial fibrillation.
A 3-dimensional computerized mapping system is utilized during this procedure to ensure the location of the different catheters in relation to your specific heart anatomy. A 3-D rendering of the heart is created with the help of a 5-spline mapping catheter that resembles a hand.
Once the ablation is complete, the physician will test the heart by speeding it up to a high rate with certain medications on board. This “stress” test is done to ensure that the ablation was successful.
- Atrial fibrillation ablations have a success rate of around 75-80%.
- Atrial fibrillation ablations in our practice take around 2 hours with respect to actual procedure time. You will spend longer at the hospital prior to and after your procedure.
What is a Fluoroless Ablation?
Dr. Makkar has specialized in fluoroless ablations. He was one of the first ones to do fluoroless ablations in the state. This means that he does not need to use x-ray (radiation) during the procedure. Instead, he relies on the 3-D map as well as intracardiac ultrasound to guide the ablation. The lack of x-ray leads to greater safety for the lab staff and most importantly, you. The same procedure performed by other physicians can expose you to an average of 30-50 minutes of fluoroscopy, which is a high dose of radiation equivalent to thousands of X rays.
What is the recovery process following the procedure?
Once the procedure is complete, the catheters will be removed from your groin and pressure will be held at the incision site for several minutes to prevent bleeding. You will then be sent to a recovery unit where you will remain on bed rest for 4-6 hours.
After your ablation, you will be admitted to the hospital. You will be taken to your room and placed on a special monitor, called telemetry. Telemetry consists of a small box connected by wires to your chest with sticky electrode patches. The box causes your heart rhythm to be displayed on several monitors on the nursing unit. The nurses will be able to observe your heart rate and rhythm.
Before you go home, we will discuss the results of your procedure with you and your family/friends. We will also go over at-home instructions as well as discuss when you will need to come into the office for a follow-up appointment.
You may still experience palpitations for some time after the ablation. This is normal for about 8 weeks post-procedure. The procedure can cause some irritation to the heart, therefore it takes some time for everything to settle.
Ablation Discharge Instructions
You will need a 1-2-week post-procedure follow-up appointment with us. Please call us at (602) 698-5820 to schedule this appointment if one was not made for you at the time of your discharge from the hospital. Your follow-up will consist of a reassessment of your symptoms and the electrical activity in your heart with EKG and cardiac monitoring.
What To Expect At Home:
- Bruising of the trunk, groin and leg around the puncture site is normal and should resolve in a few days.
- Palpitations as well as mild chest discomfort that is worsened with breathing are normal – even with a successful ablation. These symptoms should resolve within days to weeks post-procedure.
- You will be sent home with a bandage over the area which can typically be removed the day after the procedure.
- Shower as usual after the bandages are removed. You may gently wash the area with soap and water but do not scrub the puncture site.
- If you discontinued any medications pre-procedure, resume taking them unless told otherwise by your physician upon discharge from the hospital
- Do not lift over 10 lbs. for 5 days post-procedure.
- You may resume physical activity after 1-2 days but avoid any strenuous activity such as exercise for 1 week post-procedure.
- Do not take a tub bath, Jacuzzi or swim for 7 days.
- Discuss with your physician prior to discharge about when it is appropriate for you to return to work.
Call If You Experience:
- Significant redness, heat, swelling, drainage or severe pain at your puncture site. If any bleeding occurs, hold direct pressure at the site with gauze or a band-aid. If the bleeding continues past 10 minutes, call your physician and seek immediate medical attention.
- Fever of 100 degrees or higher. A high temperature can be early signs of infection.
- Lightheadedness, dizziness, numbness, tingling or double-vision.
- Difficulty swallowing.
- Significant shortness of breath.