Atrial Fibrillation Heart Rate and Pulse Range Explained

Atrial fibrillation, or AFib, is a type of irregular heartbeat that affects the heart's rhythm and can lead to serious complications. Normally, the heart beats in a coordinated and regular rhythm due to electrical impulses that stimulate the atria and ventricles to contract and pump blood throughout the body. This rhythm can be measured by checking the pulse, which typically matches the heart rate. In a healthy adult, the resting heart rate ranges from 60 to 100 beats per minute (BPM).

Understanding the Difference Between Heart Rate and Pulse in AFib

During an episode of atrial fibrillation, the electrical signals in the atria become chaotic, disrupting the normal sequence of heart contractions. As a result, the heart beats irregularly and with varying strength, leading to inconsistent pulse beats that may feel unpredictable or even absent at times. This discrepancy between the actual heart rate and the measurable pulse rate is known as a "pulse deficit."

In AFib, the heart rate can vary significantly, often exceeding the normal resting range. In some cases, the heart may beat over 100 BPM, leading to symptoms such as palpitations, shortness of breath, fatigue, and chest discomfort. These symptoms can vary in intensity depending on the severity and duration of the arrhythmia.

Low Pulse Rate and Its Implications in AFib

Interestingly, some individuals with AFib may experience a slower-than-normal pulse. This can occur when AFib is accompanied by other conduction issues, such as impaired atrioventricular (AV) node function or bundle branch block. In these cases, the pulse may drop below 60 BPM and may include long pauses between beats—sometimes lasting more than 3 or 5 seconds. These prolonged pauses can reduce blood flow to vital organs, potentially causing dizziness, fatigue, or even fainting.

Monitoring and Managing Atrial Fibrillation

Due to the unpredictable nature of AFib, it's essential for patients to undergo comprehensive cardiac monitoring. A 24-hour Holter monitor or extended cardiac rhythm monitoring can help doctors assess the full range of heart rate variability and identify patterns in AFib episodes. This information is crucial for developing an effective treatment plan tailored to the individual patient.

Management strategies may include medications to control heart rate or restore normal rhythm, lifestyle modifications, and in some cases, procedures like cardioversion or ablation. Early diagnosis and consistent monitoring are key to preventing complications such as stroke or heart failure associated with AFib.