“Sinus fibrillation” is not a recognized medical term; people searching for it are likely looking for information on atrial fibrillation (Afib). A normal heart rhythm originates from the sinus node and is called “sinus rhythm.” Afib is an irregular heart rhythm and a serious medical condition.
Understanding Atrial Fibrillation
Atrial fibrillation (Afib) is an irregular and often rapid heart rate that originates in the heart’s upper chambers, called the atria. This condition can lead to blood clots, increasing the risk of stroke and other heart complications. In a healthy heart, the sinoatrial (SA) node, often called the heart’s natural pacemaker, generates a single electrical impulse that initiates each heartbeat, resulting in a regular rhythm. This electrical signal travels through the atria and then to the ventricles, causing them to contract and pump blood efficiently.
With Afib, multiple disorganized electrical impulses fire from various locations in the atria. These chaotic signals overwhelm the SA node’s normal signals, causing the atria to quiver instead of contracting effectively. This quivering, or fibrillation, means blood isn’t efficiently pumped from the atria into the ventricles, leading to blood pooling. This inefficient pumping can cause the ventricles to beat too quickly and irregularly, often between 100 to 175 beats per minute. Afib is the most common type of heart arrhythmia.
Recognizing Atrial Fibrillation
Afib can manifest with various symptoms, though some individuals experience no noticeable signs. Common symptoms include palpitations, feeling like a fluttering, pounding, or racing heartbeat. Shortness of breath, fatigue, dizziness, or lightheadedness may also occur due to the heart’s inefficient pumping of oxygenated blood. Weakness and chest pain are additional symptoms.
Diagnosing Afib involves several non-invasive tests to assess the heart’s electrical activity and structure. An electrocardiogram (ECG or EKG) is a primary diagnostic tool, measuring the heart’s electrical signals through electrodes on the chest and limbs. Because Afib episodes can be intermittent, a standard ECG, capturing only a brief moment, might not always detect the condition. For this reason, a Holter monitor, a portable ECG device, records heart activity continuously for 24 to 48 hours or longer during daily activities.
An event recorder is another device similar to a Holter monitor, but it records heart activity only at specific times, often when symptoms are felt, and can be worn for up to 30 days. Some event recorders can also automatically record when an irregular rhythm is detected. An echocardiogram, which uses sound waves to create images of the heart, helps evaluate blood flow, size and function of heart chambers, and the condition of heart valves. While it doesn’t directly diagnose Afib, it provides important information about the condition’s impact on the heart.
Causes and Management of Atrial Fibrillation
Afib often develops due to underlying heart conditions and risk factors affecting the heart’s electrical system and tissue. High blood pressure is a common cause, leading to stiffening and thickening of heart tissue, altering electrical signal pathways. Other cardiovascular diseases like coronary artery disease, heart failure, and heart valve diseases also increase the risk. Beyond heart-specific issues, conditions such as obesity, diabetes, and an overactive thyroid gland are recognized risk factors. Sleep apnea and excessive alcohol consumption also contribute to Afib, and the risk of developing it generally increases with age, with incidence doubling each decade after 50.
Afib management focuses on two main goals: controlling heart rate and rhythm, and preventing blood clots to reduce stroke risk. Treatment often begins with medications. Rate control medications, like beta-blockers, slow the heart’s lower chambers to allow adequate filling time, even if the irregular rhythm persists. Rhythm control medications aim to restore and maintain a normal heart rhythm. Blood thinners (anticoagulants) are prescribed to prevent blood clots from forming in the atria, significantly reducing stroke risk.
Beyond medication, procedures like cardioversion can reset the heart’s rhythm; for example, electrical cardioversion involves delivering controlled electrical shocks to the chest to normalize the heartbeat, typically under mild anesthesia. Pharmacological cardioversion uses medications administered intravenously or orally to achieve the same rhythm reset. For some individuals, catheter ablation is a treatment option; this minimally invasive procedure uses heat or cold energy to create small scars in heart tissue, blocking faulty electrical signals that cause Afib. Lifestyle modifications are also important in managing Afib and reducing its risk, including maintaining a healthy weight, regular physical activity, limiting alcohol and caffeine, managing stress, and quitting smoking. It is important to consult a healthcare professional for an accurate diagnosis and a tailored treatment plan.