The human heart maintains a steady rhythm to efficiently pump blood throughout the body. Sometimes, the heart’s electrical system can malfunction, leading to abnormal heartbeats known as arrhythmias. Atrial Fibrillation (AFib) and Supraventricular Tachycardia (SVT) are two conditions involving rapid heart rates originating in the upper chambers. This article clarifies what each condition entails and compares their seriousness.
Understanding Atrial Fibrillation
Atrial Fibrillation, often called AFib, is an irregular and frequently rapid heart rhythm that originates in the heart’s upper chambers, the atria. Instead of producing a coordinated contraction, the atria beat chaotically, causing them to quiver or “fibrillate.” This uncoordinated electrical activity means blood is not effectively pumped into the lower chambers, the ventricles. Common symptoms of AFib include heart palpitations, which can feel like a fluttering or pounding in the chest, along with fatigue, shortness of breath, and dizziness.
AFib carries significant health considerations, primarily an increased risk of stroke and heart failure. When blood pools in the atria due to inefficient pumping, blood clots can form. If a clot travels to the brain, it can block blood flow and cause a stroke. The rapid and irregular heart rate associated with AFib can over time weaken the heart muscle, potentially leading to heart failure.
Understanding Supraventricular Tachycardia
Supraventricular Tachycardia, or SVT, refers to a rapid heart rate that begins in the upper parts of the heart, above the ventricles. Unlike AFib, SVT involves a regular, though very fast, heart rhythm. The heart rate during an SVT episode can range from 150 to 300 beats per minute. These episodes can start and stop suddenly, lasting from a few seconds to several days.
Individuals experiencing SVT may report symptoms such as a sudden racing heartbeat, chest discomfort, shortness of breath, and lightheadedness or dizziness. While less concerning than AFib, prolonged or very rapid SVT episodes can lead to fainting due to reduced blood pressure. In rare instances, especially if untreated or with existing heart damage, SVT could weaken the heart or, rarely, cause sudden cardiac arrest.
Comparing Severity and Risks
When comparing the seriousness of AFib versus SVT, AFib generally carries a higher risk of severe complications. The primary concern with AFib is its association with an increased likelihood of stroke. The chaotic and inefficient pumping of blood in AFib allows blood to pool in the heart’s upper chambers, raising the chance of blood clot formation. If these clots dislodge and travel to the brain, they can block blood flow, leading to an ischemic stroke. AFib can also lead to heart failure over time due to the heart working inefficiently.
In contrast, SVT, while often causing alarming symptoms, is less threatening to life and rarely leads to stroke. SVT episodes, though uncomfortable, usually do not result in blood clot formation like AFib because the heart’s rhythm remains regular. While SVT can cause fainting or, in rare cases, cardiac arrest, these instances are more likely with underlying heart damage or prolonged, severe episodes. The long-term implications of SVT are less impactful than AFib, which requires ongoing management to prevent serious cardiovascular events.
When to Seek Medical Care
Understanding when to seek medical attention for heart rhythm changes is important for both AFib and SVT. If you experience new or concerning heart palpitations, particularly if they are frequent, bothersome, or last longer than a few minutes, it is advisable to consult a healthcare provider for evaluation. A doctor can perform tests to accurately diagnose the type of arrhythmia.
Immediate medical care is warranted for severe symptoms accompanying a rapid or irregular heartbeat. These symptoms include chest pain or discomfort, severe shortness of breath, significant dizziness or lightheadedness, or fainting. These could indicate a more serious underlying issue or a complication requiring urgent intervention. Do not attempt to drive yourself to the emergency room if experiencing these severe symptoms; call emergency services immediately.
Managing These Conditions
Managing AFib and SVT involves tailored approaches to control symptoms and prevent complications. For AFib, treatment focuses on regulating heart rate and rhythm with medications like beta-blockers and antiarrhythmics. Anticoagulant medications, or blood thinners, are also crucial to reduce the stroke risk associated with AFib. Procedures like electrical cardioversion and catheter ablation can help restore normal heart rhythm.
SVT management often begins with vagal maneuvers, simple techniques that can sometimes stop an episode. Medications, including beta-blockers, may prevent recurrence or manage episodes. For persistent SVT, catheter ablation is a highly effective procedure that can permanently address the underlying electrical issue.