Atrial Fibrillation: Key Characteristics and Insights

Atrial fibrillation (AFib) is one of the most common types of arrhythmia encountered in cardiology. It is characterized by rapid, irregular, and disorganized electrical activity in the atria of the heart. This abnormal rhythm can cause the atria to beat at an astonishing rate of 350 to 600 beats per minute, significantly faster than the normal heart rhythm.

Irregular Heartbeat: A Defining Feature

Under normal conditions, the heart maintains a steady and regular rhythm. However, in atrial fibrillation, this rhythm becomes completely irregular. This irregularity is a hallmark of AFib and can often be detected through pulse examination or electrocardiogram (ECG) testing.

Variability in Heart Sounds

Another notable characteristic of atrial fibrillation is the variation in heart sound intensity. Because the heart's contractions and relaxations become unpredictable, the heart may not pump blood effectively. As a result, the heart sounds heard through a stethoscope can appear inconsistent and irregular.

Pulse Deficit: When Pulse Rate Lags Behind Heart Rate

One of the more unique aspects of AFib is the phenomenon known as "pulse deficit." Normally, the pulse rate matches the heart rate. However, during atrial fibrillation, the heart may begin to contract again before it has fully filled with blood. This results in weak contractions that fail to generate enough blood flow to create a palpable pulse in peripheral arteries. Consequently, the pulse rate measured at the wrist may be lower than the actual heart rate detected by auscultation.