Charlotte, NC
Vikram Karna, MD
Bibhusan Basnet, MD
Atrial fibrillation, also known as AFib, is the most common type of treated arrhythmia, arising from an issue with the heart’s electrical system.
In AFib, electrical signals originate from a location other than the sinoatrial (SA) node. These signals are rapid and compete for the conduction pathway, leading to a state of chaos. Subsequently, the normal coordination of the electrical signal that traverses the heart becomes disrupted; instead of a synchronized progression, the electrical impulses become disorganized. This causes the heartbeat to become quick, irregular, and less efficient. Compared to a healthy heart’s rate of 60-100 beats per minute, the atria start contracting over 300 times per minute. Consequently, blood is not effectively pumped through the heart during episodes of atrial fibrillation.
Many people with atrial fibrillation do not have any symptoms and may not be aware of them. However, you may experience palpitations (fluttering sensation in your chest), shortness of breath, chest pain, dizziness, nausea, fatigue, faintness or confusion, and sweating. You may also have trouble with everyday exercises or activities and experience pain, pressure, tightness, or discomfort over the chest.
Atrial fibrillation is frequently caused by heart disease. These include heart failure, heart valve disease, hypertension, and heart attacks(5 warning signs of heart attack). Obesity, sleep apnea, chronic obstructive pulmonary disease, abnormal heart structure, hyperthyroidism, and alcohol intoxication are other risk factors associated with atrial fibrillation.
The rapid, chaotic heartbeat means less time for atria to relax and contract, resulting in slowed blood flow. When blood does not flow smoothly, there is an increased chance of clot formation in the heart. The blood then can carry these clots to other body areas, called as thromboembolism. These moving clots can be dangerous as these clots get wedged when reaching the smaller blood vessels and decrease blood supply downstream. A blood clot lodged in small blood vessels in the brain reduces blood flow to the brain and causes injury to the brain leading to ischemic stroke. Without treatment, AFib can also cause the ventricles to beat too fast. Over time, this weakens the heart muscle and leads to heart failure.
Your stroke risk depends on age and other risk factors such as heart disease, high blood pressure (hypertension), diabetes, or vascular disease. The CHA2 DS2 -VASc stroke risk tool helps doctors quickly measure your risk of stroke. Each major stroke risk factor carries points. By adding these points, your doctor can determine your stroke risk. Higher total points mean a higher risk of stroke. Your doctor will ask questions about heart and vascular problems and other risk factors for stroke and calculate the risk to see if you need a blood thinner to prevent a stroke.
Your doctor can detect atrial fibrillation in many ways:
Your doctor individualizes the treatment strategy, considering your medical history and symptoms.
Let’s look at some of the possible strategies:
Catheter Ablation:
Catheter ablation involves inserting catheters into the heart to eliminate AFib sources and reduce the number of AFib episodes. Medications can control and maintain a regular heart rate by slowing the electrical signal traveling through the AV node. For patients who don’t have an optimal response to medications, ablation (a procedure that uses heat or cold energy to create tiny scars in the heart to block faulty electrical signals and restore a typical heartbeat) might be the better option.
This procedure destroys the tissue responsible for the arrhythmia. Ablation is not always successful and can result in serious complications such as infection, bleeding, or stroke in rare cases. The risk of recurrent atrial fibrillation is most significant in the first few weeks following the procedure. Sometimes, a pacemaker may be implanted in the system to ensure that your heart generally beats adequately after removing the problematic tissue. If this occurs, your provider may decide to repeat the process.
Plugging or closing off the left atrial appendage(Watchman Device):
The left atrial appendage is a small sac in the muscle wall of your left atrium, known as the left atrial appendage. If you cannot take blood thinners, this procedure prevents clots from forming in the area and causing a stroke. This procedure may be performed concurrently with surgical ablation or cardiac surgery by your provider.
Watchman Procedure For Afib
By closing off the left atrial appendage, blood clots that form within the left atrial appendages are prevented from entering the bloodstream. The device has been shown in clinical trials to provide comparable effectiveness in stroke prevention to warfarin.
The heart normally beats 60 to 100 times per minute, with the beats occurring at regular intervals, creating a steady rhythm. However, when there is any disruption or abnormality in the usual sequence, rate, or coordination of the electrical impulses that regulate the contraction and relaxation of the heart chambers, the beats become irregularly spaced. This irregularity in the heartbeat is known as an abnormal heart rhythm or an arrhythmia.
The blood circulation that occurs with each contraction of the heart is what we feel as the pulse in our body. The number of times the contraction of the heart occurs in a minute is what we call heart rate. When the SA node generates regular electrical impulses, the heart’s chamber contracts consistently and in a steady pattern, referred to as a regular heart rhythm. In simple terms, the regularity of your heartbeat is commonly called heart rhythm.
The heart consists of four chambers, i.e., two atria and two ventricles. Electric signal regularly originates in a small bundle of tissue known as the sinoatrial (SA) node, located in the right atrium- the upper chamber of the heart. It travels along a particular route in the heart called the conduction pathway.
Following the generation of the signal at the SA node, the atria contract, causing blood to flow from the atria into the ventricles. The signal is then routed through the atrioventricular (AV) node and into the muscle surrounding the ventricles leading to the contraction of the ventricles. When the ventricles contract, blood is pumped to the lungs and the rest of the body. This completes one cycle of heart contraction, and the next occurs with the generation of electrical impulses from the SA node.
